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2021-09-01 | The authors propose a freezing method for liquidating the consequences of oil spills using liquid nitrogen. For freezing flat surfaces contaminated with oil, a cryogenic device with a set of two-zone modules is developed. Contaminants located in hard-to-reach places or places with complex surface relief are treated with a pistol-type liquid nitrogen sprayer. A prototype pistol-type device has been created, experimental studies demonstrate the effectiveness of the proposed solution. Based on the proposed cryogenic devices, mathematical models have been developed for calculating the main parameters of freezing contaminated soil with liquid and gaseous nitrogen — the duration of the process and the final temperature. A calculation of these parameters of the oil freezing process is necessary for practical implementation of the proposed cryogenic devices, and the calculation methods used are applicable for any technogenic pollution. | Equipment for Rapid Freezing of Oil Contaminated Soil by Liquid Nitrogen for Its Subsequent Utilization | 10.1007/s10556-021-00950-9 |
2021-09-01 | Peculiar characteristics of squeeze casted hybrid aluminum matrix composites (AMCs) enable it as an appropriate candidate for various manufacturing applications but also make their machining challenging. For that reason, wire electric discharge machining (WEDM) has been preferred over conventional machining processes for the cutting squeeze casted Al2024/Al_2O_3/W hybrid composite in this study. The presence of nanoparticles in the material affects the machining performance of wire electrodes. Therefore, molybdenum and zinc-coated wires have been chosen, and cryogenic treatment has been applied to improve their machining performance. To analyze the effects of cryogenic treatment, the machining efficiency of cryogenic treated (CT) wire has been compared with non-treated (NT) wire. Besides wire type, four key input variables including pulse duration (T_ON), wire feed rate (F_R), wire runoff speed (S_W), and wire tension (T_W) have also been optimized to improve the imperative response measures including cutting speed (CS), surface roughness (SR), and kerf width (KW). Microstructural analysis of NT wire depicts a high concentration of micro-voids, micro-cracks, and deep craters, while the surface of CT wire has been observed relatively fine after the machining. Comparative analysis of both wire electrodes has declared that CT wire yields 26.96% and 15.10% superior results for CS and SR respectively, and 6.92% deprived results for KW than NT wire. Grey relational analysis (GRA) has been practiced for multi-objective optimization and presented T_ON = 3 μs, F_R = 13 m/min, S_W = 11 m/min, and T_W = 10 g as an optimal set of input variables to achieve 75.1% and 72.5% overall results with NT and CT wire, respectively. | Cryogenic treatment analysis of electrodes in wire electric discharge machining of squeeze casted Al2024/Al_2O_3/W composite | 10.1007/s00170-021-07521-5 |
2021-09-01 | Shape memory alloys (SMAs) have been explored to develop applications in several areas due to their differential capacity to recover deformations, in addition to the elastic deformation and suffered in the martensitic phase, through heating. In applications where SMAs are used as actuators, they are subject to structural and functional fatigue. The present work aims to investigate the effects of deep cryogenic treatment on the cyclic behavior of the Ni_54Ti_46 alloy under thermomechanical loading. A comparative experimental study, between the treated and the non-cryogenic materials, is performed in terms of the number of cycles until failure and the evolution of the recoverable strain and plastic strain. The cryogenic treatment consisted of immersion of sample in liquid nitrogen at − 196 °C for 6, 12, 24, and 36 h. During the tests, four levels of uniaxial heating stress and cooling rates of approximately 10 °C/s and − 13 °C/s were considered. The evolution curves of recoverable deformation show that the treated material increases on average up to 3% compared to the non-cryogenically-treated material. Using the S – N curves generated, it was observed that the fatigue life decreased with the deep cryogenic treatment, and the largest observed average reduction was 25% for 6 h of immersion. | Cryogenic Treatment Effect on Cyclic Behavior of Ni_54Ti_46 Shape Memory Alloy | 10.1007/s40830-021-00338-x |
2021-09-01 | Abstract Titanium alloys are well known with their superior properties such as corrosion resistance, specific strength; however, machining and shaping of this material are quite tricky and costly. In the present study, an attempt was made to improve the machinability of Ti–6Al–4V alloy by conducting deep and shallow cryogenic treatment. For this purpose grade, 5 in ASTM B348 titanium alloy was supplied as bar material. Cryogenic treatment was conducted to both annealed and aged state Ti–6Al–4V alloy. Machinability of different heat-treated materials was tested by using a CNC wire electro discharge machining machine. The test results were evaluated by material removal rate, surface roughness and surface hardness of the machined surface. Additionally, the electrical conductivity of different heat-treated specimens was measured. An XRD test was conducted to understand the internal changes happened with the effect of heat treatment. The results of the study show that the application of cryogenic treatment to both annealed and aged samples improved the machinability and electrical conductivity and provides better surface roughness of machined surfaces. This study suggests an alternative approach to improve the machinability of Ti–6Al–4V alloy and presents a characterization study about the effect of cryogenic treatment on Ti–6Al–4V alloy. Graphic Abstract | Improvement of the Machinability of Ti–6Al–4V Alloy Wire Electro Discharge Machining with Cryogenic Treatment | 10.1007/s12540-020-00667-z |
2021-09-01 | Cryogenic treatment is a useful method for improving the mechanical and tribological properties of a wide range of materials, especially steels. However, the results regarding the effect of this treatment on the corrosion resistance are scarce, particularly in the case of martensitic stainless steels. In our research, the influence of cryogenic treatments on the properties of two different martensitic stainless steels, namely AISI 420 and AISI 440C, is investigated. Their microstructures are studied by scanning electron microscopy and X-ray diffraction and correlated with their corrosion resistance. The electrochemical behavior of steels is studied by measuring open-circuit potential and in the course of experiments using cyclic anodic potentiodynamic polarization. It is found that the cryogenic treatment does not affect the pitting resistance of AISI 420 steel but it significantly reduces the ability of AISI 440C to achieve passivation. | Influence of Cryogenic Treatments on the Electrochemical Behavior of Two Martensitic Stainless Steels | 10.1007/s11003-021-00541-2 |
2021-08-24 | Unconventional shale gas reservoir requires fracture network for exploitation from nano-Darcy shale where reservoirs have a space-to-space variation. This study is aimed to investigate the potential of Mancos Shale formation for the purpose of hydrocarbon recovery using numerical analysis of cryogenic liquid treatment. In this study, at first, the core samples of Mancos Shale from the Late Cretaceous (upper Cretaceous) geologic development were treated before and after cryogenic liquid nitrogen for different treatment times specifically 30, 60, and 90 min, respectively. Later, the numerical simulation is used to determine the overall gas production under different confining stress scenarios with different treatment times. In this study, the candidate reservoir is simulated on a simple layer cake model having a thickness 450 ft to simulate production scenarios for different ranges of permeability and porosity. The simulation results for the Mancos shale gas reservoir are obtained with net confining stress ranging from 1000 to 7000 psi. The simulation reveals that the recovery obtained before fracture treatment was 0.0004 SCTR with quite a low production. Nevertheless, an increase in the exposure time of cryogenic treatment through the liquid nitrogen LN_2 process enhanced the gas recovery to a maximum level of 2.2 SCTR at confining stress of 7000 psi. Hence, simulation studies have shown that cryogenic liquid nitrogen treatment has a profound effect to increase the production of shale gas. | Analysis of Mancos Shale gas production scenarios under various stress mechanisms | 10.1007/s12517-021-08190-0 |
2021-08-16 | Fluorescence sensing of glutathione by tailor-made chemical sensors is a prospective technique, which could provide simple, fast, and visual detection. Herein, a fluorescence sensor based on vanadium oxide quantum dots (VO_x QDs) and permanganate (MnO_4^−) has been designed for monitoring glutathione. The bifunctional VO_x QDs, possessing rich redox chemistry and robust fluorescence (exhibiting fluorescence near 505 nm upon excitation at 450 nm), were synthesized via cryogenic-mediated liquid-phase exfoliation. In the presence of MnO_4^−, VO_x QDs induced the spontaneous formation of MnO_2 nanosheets which caused the fluorescence quenching. However, the subsequent introduction of glutathione could trigger MnO_2 reduction to Mn^2+, and the fluorescence was recovered. Based on this phenomenon, an “on-off-on” fluorescence sensor for glutathione detection was established. Under the optimal conditions, this sensor allowed detection of glutathione in the linear range of 0.5–100 μM with a detection limit of 0.254 μM. Additionally, the proposed strategy revealed the selectivity toward glutathione and the potential of practical application in the analysis of human serum, vegetable, and fruit samples. Graphical abstract | On-off-on fluorescent sensor for glutathione based on bifunctional vanadium oxide quantum dots induced spontaneous formation of MnO_2 nanosheets | 10.1007/s00604-021-04958-z |
2021-08-01 | Abstract The natural gas entering the liquefaction cycle usually consists of nitrogen, ethane, propane and also heavier hydrocarbons which are economically explainable to be separated from methane, considering that their heating values are higher than methane. In this paper, a hybrid system is developed and analyzed for liquefied natural gas, natural gas liquids and power tri-generation using LNG/NGLs recovery system, absorption–compression combined refrigeration, organic Rankine cycle and solar parabolic trough collectors. This integrated structure produces 54.12 kg s^−1 NGLs, 66.52 kg s^−1 LNG and 278.5 MW net power output. Specific power consumption, thermal and exergy efficiencies of the hybrid system are 0.3771 kWh kg^−1 LNG, 78.38% and 84.47%, respectively. The pinch method is used to extract the heat exchanger network related to the multi-stream heat exchanger of the hybrid system. To simulate the integrated structure, MATLAB programming, HYSYS and TRNSYS software with the weather conditions of Bandar Abbas city in Iran are used. The effect of natural gas composition entering the cycle on system parameters is studied and reported. Results show that with the reduction in methane percentage in natural gas to 55 mol%, specific power consumption increases to 0.6004 kWh kg^−1 LNG, and thermal efficiency decreases to 71.61%. The integrated structural behavior at different operating conditions is used to investigate the sensitivity analysis. Graphic abstract | Energy, exergy and pinch analyses of an integrated cryogenic natural gas process based on coupling of absorption–compression refrigeration system, organic Rankine cycle and solar parabolic trough collectors | 10.1007/s10973-020-10158-3 |
2021-08-01 | X-ray crystallography is the most powerful tool for obtaining structural information about protein molecules, affording accurate and precise positions for all of the atoms in the protein except for hydrogen. However, hydrogen species play crucial roles in the physiological functions of enzymes, including molecular recognition through hydrogen bonding and catalytic reactions involving proton transfer. Neutron crystallography enables direct identification of the positions of hydrogen species. [NiFe]-hydrogenase from Desulfovibrio vulgaris Miyazaki F is an enzyme that catalyzes the reversible oxidation of molecular hydrogen. It contains a bimetallic Ni–Fe active site for the catalytic reaction and three Fe–S clusters for electron transfer. Previous X-ray structure analyses of the enzyme under various oxidation conditions have revealed that the active site changes its coordination structure depending on the redox state. In the inactive air-oxidized form, an oxygen species was identified between the Ni and Fe atoms, whereas in the active H_2-reduced form, subatomic-resolution X-ray structure analysis and single-crystal EPR analyses indicated a hydride ligand between the two metal atoms. However, the assignment of the hydride moiety by X-ray crystallography remains controversial, and the proton transfer pathways in the molecule are still ambiguous. To allow neutron diffraction experiments, large crystals of [NiFe]-hydrogenase were prepared by the vapor diffusion method with the macroseeding technique according to the two-dimensional phase diagram (protein concentration vs. precipitant concentration). Neutron diffraction data were collected at approximately 2.0 Å resolution at cryogenic temperature using a gas-stream cooling system to trap short-lived intermediates in the catalytic reaction. | The Challenge of Visualizing the Bridging Hydride at the Active Site and Proton Network of [NiFe]-Hydrogenase by Neutron Crystallography | 10.1007/s11244-021-01417-0 |
2021-08-01 | Abstract Finite volume methods were used to study the process of gas expansion in the stage of a turboexpander unit (TEU) in a three-dimensional, nonstationary setting. The main objectives of the work are to verify the calculation methodology based on a real experiment, to obtain a qualitative and quantitative agreement of data for further studies of the processes occurring in the flow path of the stage of a turboexpander unit, namely, phase transitions during condensation of impurities in the bulk. Due to the fact that the experiment is only preliminary tests, there is no reliable data on the intermediate values of the macroparameters; therefore, the verification of the proposed method was carried out only in terms of the temperature at the outlet from the diffuser and the isentropic efficiency. The calculation technique used in this work, thanks to the use of sliding interfaces, made it possible to study the turboexpander unit not in parts but with the help of a unified calculation model, taking into account the leaks and overflows of the working fluid (helium). In the course of calculations, the fields of velocity, pressure, and temperature were obtained in the longitudinal and cross sections of the turboexpander unit as well as on its walls. A simplified h , s -process diagram, and the values of isentropic efficiency are determined for several points. The proposed calculation method, applied for a specific model of a turboexpander unit, can be extrapolated to other variants of the flow paths of microturbine expander units for boundary conditions and operating modes close to the original variant. To prepare an extended calculation method, it is necessary to carry out additional studies as well as to establish the limits of applicability of the finite volume method on a larger data set. | Numerical Simulation of the Gas Expansion Process in a Turboexpander Unit by the Finite Volume Method | 10.1134/S0040601521070089 |
2021-08-01 | The material having high strength to weight ratio is constantly in high demand for automotive industries to increase fuel efficiency. With this view, AZ91/5SiC (an Mg-based Particulate Metal Matrix Composites (PMMCs)) is fabricated using an in-house developed stir casting setup and characterized through Field Emission Scanning Electron Microscopy (FESEM) with Energy-Dispersive X-ray Spectroscopy (EDS) analysis. However, the machinability of PMMCs is found to be lower due to the existence of harder ceramic constituents and appropriate cutting fluid strategies are required to follow to combat this situation. But limited studies are available identifying the impact of recently developed sustainable cooling and lubrication techniques on machining performance when PMMCs is turned. To fill this bridge, customized setups of minimum quantity lubrication (MQL), cryogenic and CryoMQL machining with LN_2 have been developed to provide eco-friendly cutting fluid approaches to turn AZ91/5SiC. The cutting force, energy consumption, surface roughness ( R _ a ) and chip breakability index ( C _ in ) have been analyzed for MQL, cryogenic and CryoMQL techniques with variation in process parameters. By considering the average value of all turning tests, 64.65% and 40.39%; and 11.49% and 7.13% higher value of cutting force and energy consumption is found correspondingly for cryogenic and CryoMQL machining respectively as compared to MQL technique respectively. Overall, 25.59% and 18.35% lower values of R _ a have been observed for CryoMQL technique as compared with MQL and cryogenic machining respectively. The powder type chips with comparable higher values of C _ in have been found in all three cooling and lubrication techniques. | Application of Environmentally-friendly Cooling/Lubrication Strategies for Turning Magnesium/SiC MMCs | 10.1007/s12633-020-00588-x |
2021-08-01 | This study focuses on the effects of various cutting speeds and cutting conditions including dry, CO_2, HPC and flood on the surface integrity characteristics of the machined NiTi alloy. Machining-induced affected layer, microstructure, microhardness and XRD analysis are considered to assess the surface integrity characteristics of NiTi alloy. The findings from this current study reveal that as the cutting speed increased, the depth of the machining-induced layer decreased. While the microhardness value of the machined samples increased in all of the cutting conditions compared to the as-received hardness, the greatest increase was in the CO_2 condition, with 36%. The highest peak intensities of the B2 main austenite XRD peaks occurred at the cutting speed of 70 m/min. The full width at half maximum values of the XRD peaks increased in all of the cutting conditions, especially at the cutting speed of 20 m/min, and this situation supports the microhardness increase. The smallest crystallite size occurred under the CO_2 condition at the cutting speed of 20 m/min, while the highest dislocation density occurred under the HPC condition at the same cutting speed. | The Effect of Flood, High-Pressure Cooling, and CO_2-Assisted Cryogenic Machining on Microhardness, Microstructure, and X-ray Diffraction Patterns of NiTi Shape Memory Alloy | 10.1007/s11665-021-05854-6 |
2021-07-23 | The Shanghai High repetition rate XFEL and Extreme Light Facility (SHINE), an advanced XFEL project, is now being built at Shanghai Advanced Research Institute (SARI), Chinese Academy of Sciences. It includes a hard X-ray free electron laser and a 100 pW intense laser facilities with overall length of 3.1 km. The XFEL part including an 8 GeV LINAC and 3 undulator lines is cooled with forced superfluid and supercritical helium at 2 K/4 K. The cryogenic system of SHINE consists of test facility cryogenic system (TFCS), accelerator cryogenic system (ACCS), and undulator cryogenic system (UNCS). A dedicated control system based on Experimental Physics and Industrial Control System (EPICS) will be built to automate the cryogenic system with process control, PID control loops, real-time data acquisition and storage, alarm handler and human machine interface. It is capable of automatic recovery as well. This paper describes details of control system structure, interfaces, controllers and the integration under EPICS framework. | The cryogenic control system of SHINE | 10.1140/epjti/s40485-021-00066-7 |
2021-07-10 | High-strength materials are hard to machine with ordinary tools and necessitates tool inserts of high strength and hardness to machine them. One of the methods to improve the physical properties of an insert material is cryogenic treatment which involves the treating of materials at low temperatures. In the current experiments, two multilayer carbide tool inserts WS40PM and F40M were analyzed by cryogenically treating them. Three class of cutting tool inserts were taken for comparison: untreated, cryogenically treated and cryogenically treated and tempered (CTT). The microstructural changes were observed through scanning electron microscopy, and the change in microstructure of all classes of tool inserts was compared and contrasted. Hardness of the tool inserts was measured using Vickers microhardness tester, and the variation of crystallite size in tool inserts was examined through X-ray diffraction studies. Rate of tool wear (through flank wear) was observed by performing shoulder milling operation on the mild steel EN8 grade steel at constant velocity in a CNC vertical machining center using treated and untreated tool inserts. The results showcased the increase in insert hardness, microstructure and tool life of treated tools when compared with untreated tool inserts. Highest hardness was achieved for CTT tool inserts and was found to be 1142 HV for WS40PM and 1483 for F40M inserts, respectively. From the flank wear studies, F40M inserts experienced a wear of 203 µm and WS40PM inserts experienced 269 µm upon machining EN8 grade steel. | Effect of deep cryogenic treatment on tool life of multilayer coated carbide inserts by shoulder milling of EN8 steel | 10.1007/s40430-021-03100-7 |
2021-07-01 | Abstract The development of a system for noncontact positioning and transport of cryogenic fuel targets (CFTs) is an important task in the inertial confinement fusion (ICF) program. In this paper, we investigate the possibility of constructing a levitation system for accelerating the CFT magnetic carrier along a superconducting tape guide made of HTSC materials. | HTSC GUIDE FOR NONCONTACT TRANSPORT OF CRYOGENIC FUEL TARGETS USING A MAGNETIC CARRIER | 10.3103/S1068335621070022 |
2021-07-01 | Prosthesis production for hips, knees, and other human body elements, including dental implants and spine screws, requires eliminating any risk of material damage or contamination. Five-axis milling is the most suitable technique to manufacture tailor-made prostheses for different personalized sizes with affordable costs. Human life expectancy is growing, so the demand of a higher prosthesis lifecycle and manufacturing optimization is a current necessity. In this work, a robust five-axis milling process using cryogenic CO_2 as coolant fluid is presented and applied to a Ti6Al4V knee implant. Ti6Al4V (grade 5 and grade 23) alloys are very difficult to cut without lubri-cooling using oil emulsion coolant; however, this emulsion implies risks from introducing little oil drops entrapped in surface roughness valleys, hampering the cleaning process before patient’s surgery. CO_2 reduces this risk uncertainty, making machining operations more feasible and suitable regarding environmental sustainability. In terms of feasibility, the surface finishing, roughness, and residual stresses was analysed, obtaining a standard of IT4-IT5, N4 and compressive stresses, respectively. Virtual simulation of machining is also a key in five-axis to make a more robust industrial process. | A reliable clean process for five-axis milling of knee prostheses | 10.1007/s00170-021-07220-1 |
2021-07-01 | Abstract — The paper presents the results of studies on the effect of heat treatment modes on the microstructure, hardness, and wear mechanism under the action of pulsating contact stresses of C80W1 and 90CrSi5 tool steels. It was revealed that cryogenic treatment no later than half an hour after quenching reduces the volume fraction of retained austenite from 9 to 5 vol % in C80W1 steel and from 5 to 3 vol % in 90CrSi5 steel. The low content of the volume fraction of retained austenite in combination with the increased silicon content in 90CrSi5 steel reduced its wear resistance at contact stresses with an amplitude of 1300 ± 65 MPa in comparison with C80W1 steel. Cryogenic treatment of C80W1 steel reduced the period of high wear resistance from 30 000 to 12 000 loading cycles. For 90CrSi5 steel, the effect of cryogenic treatment on wear characteristics is insignificant due to a slight decrease in the amount of retained austenite (from 5 to 3 vol %). The implementation of the research results is promising at enterprises for the production of hardware products using a stamping tool for punching, drawing, and cold heading with maximum stresses on the engraving of the tool of the order of 1300 ± 65 MPa. The material of punches and dies can be C80W1 steel, hardened by quenching in water from a temperature of 780°C and tempering at 200°C and not subjected to cryogenic treatment. | Effect of Retained Austenite on the Wear Resistance of C80W1 and 90CrSi5 Tool Steels | 10.3103/S1068366621040127 |
2021-07-01 | During cryogenic turning of metastable austenitic stainless steels, a deformation-induced phase transformation from γ-austenite to α’-martensite can be realized in the workpiece subsurface, which results in a higher microhardness as well as in improved fatigue strength and wear resistance. The α’-martensite content and resulting workpiece properties strongly depend on the process parameters and the resulting thermomechanical load during cryogenic turning. In order to achieve specific workpiece properties, extensive knowledge about this correlation is required. Parametric models, based on physical correlations, are only partly able to predict the resulting properties due to limited knowledge on the complex interactions between stress, strain, temperature, and the resulting kinematics of deformation-induced phase transformation. Machine learning algorithms can be used to detect this kind of knowledge in data sets. Therefore, the goal of this paper is to evaluate and compare the applicability of three machine learning methods (support vector regression, random forest regression, and artificial neural network) to derive models that support the prediction of workpiece properties based on thermomechanical loads. For this purpose, workpiece property data and respective process forces and temperatures are used as training and testing data. After training the models with 55 data samples, the support vector regression model showed the highest prediction accuracy. | Predicting the martensite content of metastable austenitic steels after cryogenic turning using machine learning | 10.1007/s00170-020-06160-6 |
2021-07-01 | The shallow cryogenic (subzero) treatment (SCT) effect on the mechanical properties of the bimetallic casting used in the crushing industry has been investigated. Examination methods include sand casting, heat treatment and SCT, Charpy impact test, optical microscope, scanning electron microscope, microanalysis of the chemical composition (energy dispersive spectroscopy—EDS), x-ray diffraction, and hardness measurement. Two bimetallic castings (single casting containing two layers, one of low-carbon cast steel-LCCS-back up part and other high Cr cast iron-HCCI-working part) have been prepared by the sand casting method. They have been subjected to diffusion annealing at 1040 °C for 5 h. One of them was quenched in pressurized air till 100 °C and was tempered at 270 °C for 3 h and, and the other one has been subjected to SCT at − 84 °C for 24 h and then tempered at 270 °C for 3 h. The impact toughness values before and after SCT are determined five Charpy specimens per point. Hardness values and metallography of samples have been analyzed and compared. A remarkable change was observed in hardness and impact energy/toughness before and after SCT. | Shallow Cryogenic Treatment (SCT) Effects on the Mechanical Properties of High Cr Cast Iron: Low-Carbon Cast Steel Bimetallic Casting | 10.1007/s40962-020-00532-0 |
2021-07-01 | With outstanding mechanical advantages such as high strength, light weight, high rigidity, low thermal expansion, good resistance corrosion, and high vibration resistance, carbon fiber–reinforced polymer (CFRP) is becoming increasingly popular in the automotive, aerospace, and medical spheres. For the CFRP machining, the biggest drawback is the effect of moisture on the mechanical properties caused by the cooling liquid and tool geometry. The appreciable body of study on the influence of wetness on the mechanical quality of carbon fiber–reinforced plastic has shown that there is no suitable use for lubrication fluids in the composite industry. However, there is a significant impact on the CFRP machining capabilities caused by the geometry of the cutting tool and cryogenic liquid cooling. This paper investigated the optimal choice of the parametric combinations in the CFRP drilling process. The optimization method was proposed using the Fuzzy interference system based on grey relation analysis. The experiment data was designed according to the Taguchi method. The twist angle of the drill, the coolant gas, and the feed rate were considered as the parameter inputs while observing several multi-responses such as thrust force and temperature generated during drilling process. The optimal result, as well as the case with highest grey fuzzy reasoning grade (GFRG), indicated that the low feed rate combined with the high twist angle drill in the hybrid cryogenic CO_2-N_2 gas condition tended to minimize the value of the response output. The verification experiment results showed a good correlation with the optimal analytical result. The analysis of variance results also showed that the reliability of the data was satisfactory. | Multi-objective optimization of carbon fiber–reinforced polymer drilling process based on grey fuzzy reasoning grade analysis | 10.1007/s00170-021-07224-x |
2021-07-01 | Abstract Constitutive modeling of CoCrFeMnNi high-entropy alloy (HEA) at cryogenic temperature (77 K) and room temperature (293 K) has been investigated. The effect of temperature on deformation behavior such as twinning, forest hardening, and back stress hardening has been established. The enhanced ductility and strength of CoCrFeMnNi HEA at 77 K are due the combination of sub-grain structure, twinning, and dislocations. This phenomenon is explained in terms of quantitative values of twin volume fraction, inter-twin spacing, and dislocation density. The isotropic kinematic constitutive model is constructed with a critical twinning stress parameter to obtain the criteria for twinning initiation. The developed finite element model simulation results at 77 K and 293 K are in good agreement with the experimental data. The model displays a smooth increase in the twin volume fraction until fracture point (maximum twin fraction region). Also, different modeling parameters are obtained for each temperature to account for the changing deformation behavior. Graphic Abstract | Constitutive Modeling with Critical Twinning Stress in CoCrFeMnNi High Entropy Alloy at Cryogenic Temperature and Room Temperature | 10.1007/s12540-020-00818-2 |
2021-07-01 | Abstract A mass-economic assessment of replacement of aviation kerosene with cryogenic fuel is carried out based on the analysis of the mass sensitivity to the initial change in the aircraft parameters and on an example of transferring the Tu-204 aircraft to liquefied natural gas (Tu-206 project). | Alternative Fuel in Transport Aviation and Estimation of Its Application Efficiency | 10.3103/S1068799821030016 |
2021-07-01 | Abstract The experimentally obtained dependence on pressure P of the reduced tension E of the electric field, E / N ( N is the gas concentration), in the positive column of the glow discharge in neon at 77 K and pressure 20–200 Pa is simulated. The discharge plasma is described by the model in the diffusion-drift approximation. As a result of modeling, the сhemi-ionization rate of metastable neon atoms at 77 K is obtained to be 0.64 × 10^–9 cm^3 s^–1. It is found that, with increasing pressure, the effect of the rate of processes with the participation of metastable atoms on the relative accuracy of modeling the dependence E / N on P increases. | The Chemi-ionization Rate Constant of Metastable Neon Atoms in a Glow Discharge at Cryogenic Temperature | 10.1134/S1990793121040242 |
2021-06-24 | Densities of an air-like binary mixture (0.2094 oxygen + 0.7906 nitrogen, mole fractions) were measured along six isotherms over the temperature range from 100 K to 298.15 K at pressures up to 8.0 MPa, using a low-temperature single-sinker magnetic suspension densimeter. The measurements were carried out at T = (100, 115, and 130) K in the homogeneous gas and liquid region, and at T = (145, 220, and 298.15) K in the supercritical region (critical temperature T _C = 132.35 K); in total, we present results for 52 ( T , p ) state points. The relative expanded combined uncertainty ( k = 2) of the experimental densities was estimated to be between 0.03 % and 0.13 %, except for four values near the critical point. The largest error is caused by the magnetic suspension coupling in combination with the mixture component oxygen, which is strongly paramagnetic; the resulting force transmission error is up to 1.1 %. However, this error can be corrected with a proven correction model to an uncertainty contribution in density of less than 0.044 %. Due to a supercritical liquefaction procedure and the integration of a special VLE-cell, it was possible to measure densities in the homogeneous liquid phase without changing the composition of the liquefied mixture. Moreover, saturated liquid and saturated vapor densities were determined at T = (100, 115, and 130) K by extrapolation of the experimental single-phase densities to the saturation pressure. The new experimental results were compared with the mixture model of Lemmon et al . for the system (nitrogen + argon + oxygen) and the GERG-2008 equation of state. | Density Measurements of an Air-Like Binary Mixture over the Temperature Range from 100 K to 298.15 K at Pressures up to 8.0 MPa | 10.1007/s10765-021-02871-4 |
2021-06-16 | This paper presents the comparative analysis of M-35 high-speed steel tool with the cryogenic and conventional heat treatment process. Phase transformation is an effective way to improve the tool material properties. The investigation observes the influence of the cryogenic process on roughness and tool wear of M35 single point cutting tool. It observed that for a cryogenic tool due to an increase in the hardness, the resistance of the work piece become low. Moreover, scanning and microscopy performed using a scanning electron microscope to analyses the variation in microstructure characteristics. The analysis of variance (ANOVA) technique has employed to investigate the highest contributing factor process parameters with experimental validation. The tool steel electrodes are carried out with heat treatment that gives the desired results. The treatment at a very low temperature at cryogenic state is carried out. | Tool Wear and Surface Roughness in M 35 Single Point Cutting Tool Steel Under Non-cryogenic and Cryogenic Condition | 10.1007/s40735-021-00551-2 |
2021-06-01 | Regenerative cooling of thrust chamber is the unique solution for the thermal management of high heat flux generated inside the combustion chamber of Cryogenic rocket engine. Heat is transferred from combustion hot gas to coolant through the channels provided on inner copper shell, thereby cools the inner wall of the nozzle. A novel technique of providing copper foam inside the channels will act as an infinite fin and also act as barrier for coolant stratification. This will improve the heat transfer to the coolant and reduce the nozzle wall temperature. Heat transfer improvement with copper foam inserts to the coolant channel is demonstrated through experiments with simulated fluids. Experiments are conducted with simulated hot gas chamber and coolant channels using water as the coolant. Copper foam with high porosity is selected to fill the channels. Hot tests are carried out with copper foam filled coolant channels and measured the coolant temperature rise and pressure drop across the channels. Tests are repeated with similar hot gas condition, but without inserting copper foam inside the channels. A substantial enhancement in heat transfer to the coolant is observed with copper foam inserts experiments, which will reduce the wall temperature. This gives a good handle on the life cycle improvement of multi-start cryogenic engines for future space transportation systems. This paper details the specification of copper foam, hardware design, experiments and measurements, and the application of the augmentation of heat transfer coefficient in operating cryogenic engines. | A Technology for Improving Regenerative Cooling in Advanced Cryogenic Rocket Engines for Space Transportation | 10.1007/s42423-020-00071-0 |
2021-06-01 | Magnesium alloys are biocompatible materials that are not only used in biomedical implants but also in many engineering load-bearing applications due to their high strength to density ratio. However, machining of these alloys is somehow challenging, for example, magnesium alloy (AZ31B) is prone to ignition risk at relatively low temperatures during various machining processes. This ignition risk can be avoided by performing machining under cryogenic conditions. In the present research work, 2D finite element-based analysis of orthogonal cutting process of magnesium alloy (AZ31B) is performed considering both cryogenic and dry machining environments. Finite element simulations are performed by varying the cutting speed and uncut chip thickness. A widely employed, damage-based Johnson-Cook flow stress model is exploited to perform coupled thermo-mechanical cutting simulations. Cutting forces and temperatures are the major output parameters of interest in the work. The resultant cutting forces predicted by FE analysis for cutting speed of 100 m/min and for uncut chip thickness of 0.1 mm vary by 19% and 16% for cryogenic and dry machining conditions, respectively, when compared with available experimental results from literature, whereas, in the workpiece body, temperature variations of 14% and 2% have been found for cryogenic and dry machining conditions, respectively. Promising results of numerical model may help to further investigate and optimize the process. | Numerical investigations of cutting temperature and cutting forces in cryogenic assisted turning of magnesium alloy | 10.1007/s00170-021-06989-5 |
2021-06-01 | In Indian Space Research Organization (ISRO), the studies for the development of cryogenic propulsion were initiated in early 1980’s. The first cryogenic turbopump design (C12) in ISRO was made for 12 tonne (T) thrust engine identified for Geosynchronous Satellite Launch Vehicle (GSLV). The C12 turbopumps have undergone only initial developmental and design validation tests. The specific objective of attaining indigenous capability to launch Indian National Satellite-II (INSAT-II 2.5 T) spacecraft to geo transfer orbit (GTO) led to the need for developing a high-performance stage combustion (SC) cycle cryogenic engine. This cryogenic upper stage (CUS) engine forms the third stage of GSLV-MarkII (GSLV-MkII) launch vehicle (LV). The design check, development, extensive qualification and acceptance tests for these turbopumps were carried out and turbopumps are being used in GSLV-MkII LV. The need for launching 4 T class satellite to GTO led to the development of a high thrust 20 T cryogenic engine (CE-20). The design and development of these turbopumps were indigenously carried out. These turbopumps are rotor dynamically configured and its bearings and seals were indigenously developed. Turbopumps for CE-20 engine has successfully undergone development, qualification and acceptance tests and is being used in GSLV-MkIII vehicle. CE-20 engine turbopumps are the first indigenously designed, realised and qualified high speed turbopump in ISRO. To increase the payload capability of GSLV-MkIII LV and to meet ISRO’s future LV programme, Liquid Propulsion Systems Centre (LPSC), has taken up the development of a 200 T semicryogenic engine (SE-2000). Preliminary design review (PDR) of turbopumps are completed, hardware realisation and developmental tests are in progress. | Development of Turbopump Systems for Cryogenic and Semicryogenic Propulsion Systems of ISRO | 10.1007/s41403-020-00189-5 |
2021-05-25 | The European Spallation Source (ESS) is a neutron-scattering facility funded and supported in collaboration with 13 European countries in Lund, Sweden. Cryogenic cooling at ESS is vital particularly for the linear accelerator, the hydrogen target moderators, a test stand for cryomodules, the neutron instruments and their sample environments. The paper will focus on the control system design for the different cryogenic subsystems, hardware and software selected, industry and in-house development, advantages and disadvantages of the chosen setup and operational experience. There is also a lessons learned, feedback from providers and stakeholders and an outlook for further development described. | ESS Cryogenic Controls Design | 10.1140/epjti/s40485-021-00065-8 |
2021-05-01 | The microstructure evolution and the pitting corrosion resistance of a supermartensitic stainless steel after deep cryogenic treatment process were clarified through X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy (TEM) and electrochemical methods. The results showed that the microstructure of supermartensitic stainless steel mainly consisted of reversed austenite, tempered martensite, and M_23C_6 carbides after tempering. The deep cryogenic treatment promoted the refinement of the martensite laths and the precipitation of the carbides in comparison with the traditional process. TEM analysis indicated that the segregation of Si atoms at the boundary was found at the interface between carbide and martensite. The pitting corrosion potential of the specimens subjected to deep cryogenic treatment decreased with the elevated tempering temperature, and the lowest pitting corrosion potential was found at the tempering temperature of 650 °C. The sensitivity of the pitting corrosion potential was attributed to the precipitation of M_23C_6 carbides and Si atoms segregation. Si atoms segregation engendered the formation of Cr-depleted zone near M_23C_6 and impeded the recovery of Cr-depleted zone. | M_23C_6 precipitation and Si segregation promoted by deep cryogenic treatment aggravating pitting corrosion of supermartensitic stainless steel | 10.1007/s42243-020-00514-w |
2021-05-01 | This paper focused on the performance of tungsten carbide end mills in machining of AISI H13 hot work tool steel under dry and wet conditions. The tool performance was evaluated in terms of resultant cutting force (Fc), average surface roughness (Ra) and tool life. In the milling tests, four categories of end mills were used: untreated (U), cryo-treated (CT), cryo-treated and tempered uncoated (CTT) and TiAlN/TiN multilayer coated (MLC). The tests were performed at four cutting speeds (80, 100, 120, 140 m/min), three feeds (0.08, 0.12, 0.16 mm/rev) and a depth of cut (2 mm). The test results showed that the lowest values of Fc and Ra were obtained with the use of MLC end mills. However, the cryogenic treatment was also effective on decreasing Fc and Ra. In addition, while the CTT end mills provided a slight improvement in tool life under dry conditions, they showed a remarkable improvement of 126.1% in comparison with the untreated ones under wet conditions. Although the CTT end mills exhibited a superior performance to U and CT ones, the MLC end mills were much more resistant to abrasive wear. This study is organized into two parts (WC-Co and HSS) to observe the effects of deep cryogenic treatment on performance of two different tool materials and to compare cryo-treated end mills with multilayer coated ones. This part is related to the cryogenic treatment of tungsten carbide end mills, whereas part two is regarding cryo-treated HSS end mills. | Performance of Multilayer Coated and Cryo-Treated Uncoated Tools in Machining of AISI H13 Tool Steel—Part 1: Tungsten Carbide End Mills | 10.1007/s11665-021-05656-w |
2021-05-01 | This part of the study aimed to investigate the effects of cryogenic treatment applied to uncoated high speed steel (HSS) end mills on cutting forces (Fc), surface roughness (Ra), and tool life. The milling tests were performed at four cutting speeds (40, 50, 60, and 70 m/min), three feeds (0.018, 0.024, and 0.03 mm/rev), and a depth of cut (2 mm) under dry and wet conditions. Three categories of uncoated HSS end mills were used in the tests: conventional heat treated (CHT), cryo-treated (CT), cryo-treated and tempered uncoated (CTT), and TiAlN/TiN multilayer coated (MLC) end mills. The test results showed that the lowest values of Fc and Ra were measured with the use of MLC end mills. However, the cryogenic treatment provided in a reduction in Fc and Ra values. In addition, under wet conditions, the CTT end mills exhibited better performance than the CHT ones by 71.4%. The test results showed while cryogenic treatment is a useful and cheap application in steels, it does not have the ability to compete with coating technology in terms of tool life in milling of hot work tool steel. This paper is organized into two sections. In the first section, cutting performance of cryo-treated and multilayer coated end mills is evaluated. In the second section, performance comparison of cryo-treated WC-Co (Part 1), HSS (Part 2), and MLC end mills in milling of AISI H13 hot work tool steel is presented. | Performance of Multilayer Coated and Cryo-treated Uncoated Tools in Machining of AISI H13 Tool Steel—Part 2: HSS End Mills | 10.1007/s11665-021-05657-9 |
2021-05-01 | The conventional process employed for the removal of N_2 in a natural gas upgrading facility is cryogenic distillation (CD) and entails a significant investment outlay. Operation of the CD unit occurs at approximately 40 bar and − 120 °C, provided by a suitable refrigeration system. At such a low temperature, significant pre-treatment of the feed gas is required to prevent hydrate formation, solidification of CO_2 and heat exchanger corrosion damage from mercury. In the current study, the conventional nitrogen removal unit (NRU) using CD is compared to the use of an optimized 9-step pressure vacuum swing adsorption (PVSA) detailed process model employing a Takeda carbon molecular sieve as the adsorbent. The PVSA unit preferentially adsorbs N_2 based upon kinetic selectivity of the carbon molecular sieve. Nitrogen rejection by PVSA allows a higher tolerance to the contaminant levels over CD. The impact of this advantage on the overall performance of the entire natural gas upgrading process is evaluated by analysing, in HYSYS, the unit operations upstream and downstream of the CD unit. By employing dimethylethanolamine solvent for acid gas scrubbing and relocating the C_2+ fractionation unit upstream of the NRU, the natural gas upgrading process is shown to be more profitable for the production of pipeline gas from raw natural gas at flow rates of up to 40 MMscfd (versus the currently accepted breakeven at 15 MMscfd) using PVSA instead of CD for the NRU. | Economic assessment of a natural gas upgrading process using pressure vacuum swing adsorption for nitrogen removal | 10.1007/s10450-021-00302-2 |
2021-05-01 | Abstract 2219 Al–Cu alloy transition rings are widely used in launch vehicles. However, the coarse and agglomerated second-phase Al_2Cu particles significantly deteriorate the mechanical properties and ductility of 2219 Al–Cu alloy rings manufactured by traditional thermal deformation processes. In this study, cryogenic deformation (− 190 °C) is applied for the manufacturing of 2219 Al–Cu alloy rings to alleviate this problem. The effects on the evolution of second-phase Al_2Cu particles and the mechanical properties of the T8-aged samples were examined in comparison with the results of room-temperature (25 °C) and conventional thermal deformation at 480 °C. The results indicate that cryogenic deformation can effectively produce high-density dislocations and strongly crush coarse particles, promoting the dissolution of Al_2Cu particles and improving their distribution in the Al matrix when combined with subsequent solution treatment and rolling processes. As the deformation temperature was decreased from 480 to −190 °C, the area fraction of the coarse particles was decreased from 1.55 to 0.47%, while their mean size was decreased from 11.8 to 8.3 μm. Correspondingly, the uniformity and density of the precipitates after T8 aging were improved. Thus, the mechanical properties of the T8-aged samples were improved with decreasing deformation temperatures; the average ultimate tensile strength, yield strength, and elongation were increased by 20 MPa, 22 MPa, and 3.1% at room temperature. Graphic Abstract | Effects of Cryogenic Deformation on Second-Phase Al_2Cu Particles and Mechanical Properties of 2219 Al–Cu Alloy Rings | 10.1007/s12540-019-00468-z |
2021-05-01 | Liquid nitrogen(LN2) cryogenic machining is a green, sustainable, and high-performance machining technology. LN2 cryogenic machining of TC4 can significantly strengthen the local cooling environment of cutting, accelerate the heat dissipation, thus effectively reduce the cutting temperature, and suppress the generation of thermal stress, reduce the residual tensile stress on the workpiece surface. In this paper, a finite element model(FEM) of numerical prediction is established to analyze the effect of LN2 cryogenic machining on residual stress distribution. Firstly, mechanism analysis of surface residual stress is carried out to explore the source of residual stress during TC4 cryogenic turning. Next, to observe residual stress distribution clearly, the cutting zone separation model is designed, and then, the material model is built to reflect the change of material properties. Then, a FEM of the numerical prediction made up of explicit dynamic solution module and standard static solution module is established to simulate residual stress distribution; after that, residual stress can be ultimately acquired by linear superposing the above two module simulation results. Based on FEM proposed in this paper, the effect of LN2 cryogenic machining on surface residual stress distribution of TC4 is analyzed, and it is indicated that LN2 cryogenic machining can reduce the residual tensile stress effectively. Finally, the experiment is carried out, and the results show that the general trend of the prediction model is the same as that of the experimental results, which greatly verify the availability of the prediction model. Research provides some reference for the numerical prediction and suppression of residual stress in the future. | Numerical prediction of machining-induced surface residual stress for TC4 cryogenic turning | 10.1007/s00170-021-06805-0 |
2021-04-13 | The BEPCII project is for upgrading the Beijing Electron Positron Collider to reach a higher luminosity. The cryogenic system has been firstly designed and deployed in BEPCII, which provides cooling capacity for SRF cavities, SCQ and SSM. The cryogenic control system consists of Siemens PLC for the refrigerator control and “PLC + IOC” for superconducting device control. The BEPCII machine commissioning with beam started in October 2006. This paper describes the design and the development of the cryogenic control system. | The cryogenic control system of BEPCII | 10.1140/epjti/s40485-021-00064-9 |
2021-04-01 | Abstract Analytical expressions to calculate the geometrical characteristics of ac high-voltage high-current cryogenic current leads have been presented. An algorithm to calculate the temperature dependence of specific resistance and thermal conductivity coefficient of technical copper at low temperatures depending on the metal purity has been developed and described. | Methods to Determine the Characteristics of AC Cryogenic Current Leads | 10.3103/S1068371221040088 |
2021-04-01 | In this paper, effects of the cooling mode used in grinding of Hardox 500 on the material grindability, ground surface integrity, and multi-pass micro-scratching wear resistance are investigated. Three modes are experimented: dry grinding, soluble oil, and cryogenic cooling modes. Results showed that the cryogenic cooling achieved high levels of work hardening and compressive residual stresses. Moreover, it was found that the cryogenic cooling improves the multi-pass micro-scratching wear resistance of Hardox 500 comparatively with the polished state and ground surfaces under dry or soluble oil conditions. The improvement rates of the wear volumes generated by the cryogenic cooling represent 46% and 63% of the volumes generated for the polished state when scratch load of 10 N and 20 N were applied respectively. These improvements are discussed based on the integrities of the scratched surfaces and sub-surfaces. | Effects of the cooling mode on the integrity and the multi-pass micro-scratching wear resistance of Hardox 500 ground surfaces | 10.1007/s00170-021-06719-x |
2021-04-01 | The usage of cryogenic fluid is increasing in the machining industries especially to cut the materials having a lower machinability like Nimonic 90, a nickel-based alloy. However, the comparison of flood coolant and LCO_2 as a cryogenic fluid based on machining performance has not been found for machining Nimonic 90. In this regard, this study compares LCO_2 and conventional mineral oil-based flood coolant on the basis of machining performance while turning Nimonic 90. The effect of turning process parameters (cutting speed ( v _ c ), feed ( f ), and depth of cut ( a _ p )) and cutting fluids has been identified by analyzing machinability indicators like cutting force, flank tool wear, power consumption, surface roughness in terms of R _ a , and chip morphology. Increment of 34%, 25%, and 24% in cutting forces has been observed for cryogenic turning using LCO_2 in comparison with wet machining when the values of a _ p are 0.75, 0.50, and 0.25 mm, respectively. A decrement of 63% tool wear has been seen in LCO_2 cryogenic fluid in contrast to wet machining at higher values of v _ c , f , and a _ p . The superior surface finish has been found in wet machining, while lesser power consumption was recorded for LCO_2 as a cutting fluid. Cryogenic machining provided better chip breakability in comparison with wet machining. | Machinability analysis of nickel-based superalloy Nimonic 90: a comparison between wet and LCO_2 as a cryogenic coolant | 10.1007/s00170-021-06793-1 |
2021-04-01 | This study investigated the effect of deep cryogenic treatment (−140 °C) on the wear resistance, hardness, wear rate and electrical conductivity of X153CrMoV12 steel. The results showed that with deep cryogenic treatment, the friction coefficient was increased by 64.67% compared to that of traditional heat treatment. In addition, it was observed that fine carbide was formed, the carbide rate increased, and the particles were homogeneously dispersed by the deep cryogenic treatment. The difference in the wear rate of deep cryogenic treatment 2 (Cry-2) and deep cryogenic treatment 1 (Cry-1) sample was 33.6 and 29.6% higher than that of the conventional heat treatment (CHT) sample, respectively. The microhardness value of Cry-2 and Cry-1 sample was 9.9 and 8.3% higher than that of the CHT sample, respectively. With Cry-2, the wear rate was reduced by 50.7% compared to CHT samples. | Investigation of the Effect of Deep Cryogenic Process on the Tribological Properties of X153CrMoV12 Mold Steel | 10.1007/s11665-021-05599-2 |
2021-04-01 | This research work investigated the influence of friction stir processing under cryogenic treatment on the wear and corrosion behavior of an extruded AZ31B alloy. The experimental work that employed rotational speeds of 800, 1000, and 1200 rpm have been used, keeping the tool feed rate constant at 60 mm/min. The wear mechanism of the AZ31B alloy and cryogenic friction stir processed specimens were studied using a high magnification of SEM images. A lower wear rate was attained under cryogenic conditions which are around 20% better than the base metal. The results revealed the achievement of a lower corrosion rate at the rotational speed of 1000 rpm. The presence of fine grains and the absence of defects in the processed region lead to higher hardness. | Wear and Corrosion Behavior of Cryogenic Friction Stir Processed AZ31B Alloy | 10.1007/s11665-021-05636-0 |
2021-03-10 | Abstract Stanene (Sn)-based materials have been extensively applied in industrial production and daily life, but their potential biomedical application remains largely unexplored, which is due to the absence of the appropriate and effective methods for fabricating Sn-based biomaterials. Herein, we explored a new approach combining cryogenic exfoliation and liquid-phase exfoliation to successfully manufacture two-dimensional (2D) Sn nanosheets (SnNSs). The obtained SnNSs exhibited a typical sheet-like structure with an average size of ~ 100 nm and a thickness of ~ 5.1 nm. After PEGylation, the resulting PEGylated SnNSs (SnNSs@PEG) exhibited good stability, superior biocompatibility, and excellent photothermal performance, which could serve as robust photothermal agents for multi-modal imaging (fluorescence/photoacoustic/photothermal imaging)-guided photothermal elimination of cancer. Furthermore, we also used first-principles density functional theory calculations to investigate the photothermal mechanism of SnNSs, revealing that the free electrons in upper and lower layers of SnNSs contribute to the conversion of the photo to thermal. This work not only introduces a new approach to fabricate 2D SnNSs but also establishes the SnNSs-based nanomedicines for photonic cancer theranostics. This new type of SnNSs with great potential in the field of nanomedicines may spur a wave of developing Sn-based biological materials to benefit biomedical applications. 2D Sn nanosheets (SnNSs) were prepared through the combination of cryogenic exfoliation and liquid-phase exfoliation. The functionalized 2D SnNSs have good stability, superior biocompatibility, high photothermal conversion efficiency, and multimode imaging capability. | Cryogenic Exfoliation of 2D Stanene Nanosheets for Cancer Theranostics | 10.1007/s40820-021-00619-1 |
2021-03-01 | Background High energy photon source (HEPS) is the fourth-generation light source, which uses a large number of high-performance insertion devices to generate synchrotron radiation. The control system is an important part of the insertion device (ID). Purpose Cryogenic permanent magnet undulator (CPMU) is one kind of IDs that works in liquid nitrogen temperature and ultra-high vacuum environment, and its control system is more difficult and complex than in-air ID. The design of the control system for CPMU will be introduced in detail. Method The sub-systems include high-precision magnetic gap control, safety protection, measurement and compensation of magnetic gap at cryogenic temperature and cryogenic temperature monitoring. Mature, reliable, stable technical schemes are designed to meet the technical specifications of sub-systems. Results The experiment results show that the magnetic gap motion accuracy can be controlled within 0.2–0.3 μm under the step size of 1 μm. The safety protection system has been tested in turn, and the predetermined protection can be achieved. The average value of magnetic gap cold contraction is 1.512 mm measured by optical micrometer, and the compensation is realized by software. The average temperature of the main magnet structure measured by the temperature sensors is 81.0 K, and the temperature gradient is 0.7 K/m. The temperature monitoring is reliable and stable. Conclusion The CPMU control system which is based on EPICS has been successfully applied to the CPMU prototype, and the test results have met the design specifications. | Control system for cryogenic permanent magnet undulator (CPMU) of high energy photon source (HEPS) | 10.1007/s41605-020-00227-4 |
2021-03-01 | The results of an experimental study of the mechanical properties of carbon fiber-reinforced plastics (CFRP) made by the “wet” winding method in the temperature range of room temperature to −196°C with different reinforcement schemes are presented. The temperature dependences of strength, plasticity and elasticity characteristics of these materials in tensile and three-point bending tests are obtained. The elastic modulus of CFRP with a longitudinal scheme of reinforcement in a given temperature range is at the level of 160 GPa. The ultimate stress of the material at room temperature is 1370 MPa. The temperature dependence of this characteristic is close to linear and practically coincides with that of bending. The low-temperature hardening, estimated by the change in the value of the ultimate stress due to cooling, reaches 39%. The mechanical characteristics of CFRP with a transverse reinforcement scheme both in tension and in bending in the considered temperature range have rather low values and are determined mainly by the matrix properties. When cooling from 20 to −196°C, the elastic modulus of CFRP with a ±45° reinforcement scheme increases by 55%, and its low-temperature hardening is 40%. At the same time, the elastic modulus and ultimate stress are six to eight and ten times, respectively, lower than the similar characteristics of CFRP with the longitudinal reinforcement scheme. Fracture of such a composite at all investigated temperatures occurs locally by shifting at an angle of 45° because of delamination of the material. | Mechanical Properties of Carbon Fiber-Reinforced Plastics at Cryogenic Temperatures | 10.1007/s11223-021-00281-3 |
2021-03-01 | The effects of traditional heat treatment (quenching and then tempering) and deep cryogenic treatment on the microstructure and mechanical properties of a low-carbon high-alloy martensitic bearing steel were studied by Rockwell hardness test, X-ray diffractometry, scanning electron microscopy and transmission electron microscopy. The results show that the deep cryogenic treatment promotes the transformation of the retained austenite to martensite during cooling, which leads to the hardness of the sample after deep cryogenic treatment higher than that at the quenched state. Also, the carbon content in the martensite matrix after different treatments was calculated and the results indicated that deep cryogenic treatment can promote the segregation of carbon atoms in martensite to dislocations. The segregated carbon atoms act as and grow into nuclei for the formation of fine carbide particles during subsequent tempering. And this resulted in the fact that the hardness of the tempered experimental steel after deep cryogenic treatment is higher than that without deep cryogenic treatment. | Effects of traditional heat treatment and a novel deep cryogenic treatment on microstructure and mechanical properties of low-carbon high-alloy martensitic bearing steel | 10.1007/s42243-020-00527-5 |
2021-03-01 | Cryogenic cooling is attributed as a green option to counter the high temperatures developed in machining process. The parameters specific to the cryogenic cooling such as jet radius and jet location have controlling influence on the machining performance. Inconel 718 is one of the most prominent aeronautic alloys, mainly used in the aerospace industry due to its high strength and ability to retain properties at very high temperatures. Inconel 718 is a hard to cut material due its low thermal conductivity and work hardening behavior. The present study that investigates the impact of cryogenic cooling using liquid nitrogen coolant on orthogonal turning of Inconel 718 for different values of jet radius, jet location and cutting speeds. The study incorporated a finite element model to simulate the different machining test conditions. The virtual assessment of cryogenic cutting process is beneficial for the decision making that how these parameters can contribute towards final decision making. The dissipation of heat at cutting edge and presence of jet of cryogenic coolant was simulated and analyzed for different jet radii, jet locations and cutting speeds. The study detected shear angle and evaluated chip compression ratio to understand the plastic deformation and related effects. The study revealed that cutting temperature decreased with increasing flow of LN2 at the cutting edge while the cutting force increased with high flow of coolant. | Role of jet radius and jet location in cryogenic machining of Inconel 718: a finite element method based approach | 10.1007/s12008-020-00703-7 |
2021-03-01 | In this study, a low-dropout voltage regulator (LDO) system composed of two LDOs, which can operate in the temperature range of 77–400 K, has been developed. Cryogenic and typical transistor models of the 180 nm UMC CMOS process have been employed in the design process. Both LDOs can provide a load current of 100 mA while generating four different output voltage levels (0.9 V, 1.2 V, 1.5 V, 1.8 V). The LDO system provides 70 mV, 60 mV, 60 mV, and 50 mV dropout voltages at 77 K, and 111 mV, 108 mV, 110 mV, and 82 mV dropout voltages at 400 K, for the output voltage levels 0.9 V, 1.2 V, 1.5 V, and 1.8 V, respectively. Post-layout simulation results of the overall LDO system present that the output voltage varies by 30 mV over the broad range of temperatures from 77 K to 400 K. | A wide-temperature range (77–400 K) CMOS low-dropout voltage regulator system | 10.1007/s10470-020-01715-9 |
2021-03-01 | The versions of nonlinear defining relations and characteristics of nonlinear fracture mechanics controlling and simulating the service life, survivability, and durability of parts of modern power and energy structures operating at low, cryogenic temperatures are investigated. | Low-Temperature Crack Resistance of Cryogenic Structures | 10.1007/s11223-021-00291-1 |
2021-03-01 | The materials used in variable temperature conditions are required to have excellent thermal fatigue performance. The effects of laser shock processing (LSP), solid solution and aging treatment (T6), and cryogenic treatment (CT) on both microstructure and thermal fatigue performance of ZCuAl_10Fe_3Mn_2 alloys were studied. Microstructure and crack morphology were then examined by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The result showed that, after being subjected to the combination treatment of T6+CT+LSP, the optimal mechanical properties and thermal fatigue performance were obtained for the ZCuAl_10Fe_3Mn_2 alloy with the tensile strength, hardness, and elongation of 720 MPa, 300.16 HB, and 16%, respectively, and the thermal fatigue life could reach 7,100 cycles when the crack length was 0.1 mm. Moreover, the ZCuAl_10Fe_3Mn_2 after combination treatment shows high resistance to oxidation, good adhesion between the matrix and grain boundaries, and dramatically reduced growth rate of crack. During thermal fatigue testing, under the combined action of thermal and alternating stresses, the microstructure around the sample notch oxidized and became loose and porous, which then converted to micro-cracks. Fatigue crack expanded along the grain boundary in the early stage. In the later stage, under the cyclic stress accumulation, the oxidized microstructure separated from the matrix, and the fatigue crack expanded in both intergranular and transgranular ways. The main crack was thick, and the path was meandering. | Effects of laser shock processing, solid solution and aging, and cryogenic treatments on microstructure and thermal fatigue performance of ZCuAl_10Fe_3Mn_2 alloy | 10.1007/s41230-021-0072-4 |
2021-03-01 | Accurate detection of quantum states is a vital step in the development of quantum computing. Image-charge detection of quantum states of electrons on liquid helium can potentially be used for the readout of a single-electron qubit; however, low sensitivity due to added noise hinders its usage in high-fidelity and high-bandwidth (BW) applications. One method to improve the readout accuracy and bandwidth is to use cryogenic amplifications near the signal source to minimize the effects of stray capacitance. We experimentally demonstrate a two-stage amplification scheme with a low power dissipation of $${90}\,\upmu \hbox {W}$$ 90 μ W at the first stage located at the still plate of the dilution refrigerator and a high gain of $${40}\,\hbox {dB}$$ 40 dB at the second stage located at the 4 K plate. The good impedance matching between different stages and output devices ensures high BW and constant gain in a wide frequency range. The detected image-charge signals are compared for one-stage and two-stage amplification schemes. | Cryogenic amplification of image-charge detection for readout of quantum states of electrons on liquid helium | 10.1007/s10909-020-02552-w |
2021-03-01 | AA 6082-T6 extruded flat bars were reduced to four different thicknesses, viz., 2 mm, 3 mm, 4 mm and 5 mm, using room temperature rolling and subsequently solution treated to obtain homogenized grain structure. These solution treated plates were subjected to cryogenic temperature rolling by immersing in liquid nitrogen before each pass to achieve thickness reductions of 50%, 66.66%, 75% and 80% to 1 mm final thickness. These samples with different cryogenic rolling strains and the same final thickness, clamped on the periphery, were subjected to normal high-speed impact by conical nosed cylindrical projectiles over a velocity range of 50–250 m/s and the projectile impact and residual velocities were recorded. These experimentally measured projectile impact and residual velocities were fitted into Lambert and Jonas model to characterize its parameters. Predicted Lambert and Jonas ballistic limit velocity wise, the samples with 75% reduction performed better when compared with other reductions. The maximum (i.e. 72.5 J) and the minimum (i.e. 15.28 J) energies were dissipated by the sample with 66.66% reduction shot at impact velocity of 216.99 m/s and the sample with 80% reduction impacted at velocity of 243.49 m/s, respectively. The samples with 66.66% reduction demonstrated outstanding energy dissipation, especially at higher impact velocities, in contrast to the samples with other reductions. | Behavior of Thermo-Mechanically Processed AA 6082 Aluminium Alloy Impacted by Conical Projectiles | 10.1007/s40870-020-00265-5 |
2021-03-01 | Background Liquid xenon time projection chamber (LXe TPC) is widely used in high-energy physics experiments such as particle detection and neutrino (or neutrinoless) double beta decay. The charge readout accuracy of the LXe TPC directly affects the measurement results and success of the experiments. Because liquid xenon needs to maintain a cryogenic temperature between 162 and 165 K at atmospheric pressure, the charge generated in the LXe TPC always needs to be read out in the cryogenic environment for minimizing the input capacitance, which has effect in determining the output noise of the charge amplifier. Purpose Design a charge readout electronics system applicable to LXe TPC and research a data analysis method to get the exact amount of charge by analyzing the waveform at that output of the designed electronics system. Methods Design a multi-channel charge-reading application specific integrated circuit (ASIC) that can operate in the cryogenic environment. The signals and power supply of the ASIC are connected to an electronics system at room temperature through micro-coaxial cables. The electronics at room temperature complete the sampling of the ASIC output. A data acquisition device receives the sampled waveform data and calculates the charge measurement resolution by Gaussian fitting. Results The designed ASIC and selected micro-coaxial cable can work in stable condition under the cryogenic environment of 165 K. The analyzed integral nonlinearity of the charge measurement of the chip is 0.83% in the range from 1 to 50 fC, and the charge measurement resolution of the chip is lower than 900 $$\hbox {e}^-$$ e - RMS. Conclusion In this paper, a preliminary study of the charge readout method based on the system structure of self-developed ASIC, micro-coaxial cable, and data readout electronics is completed for LXe TPC. The system test results indicate that the designed ASIC can work normally in the cryogenic temperature of 165 K with a high dynamic range and good linearity of the charge measurement. Further work can be done to reduce the charge measurement resolution of the system to 200 $$\hbox {e}^-$$ e - RMS. | Study on low noise cryogenic charge readout electronics for liquid xenon time projection chamber | 10.1007/s41605-020-00219-4 |
2021-03-01 | When machining metastable austenitic stainless steel with cryogenic cooling, a deformation-induced phase transformation from γ-austenite to α′-martensite can be realized in the workpiece subsurface. This leads to a higher microhardness and thus improved fatigue and wear resistance. A parametric and a non-parametric model were developed in order to investigate the correlation between the thermomechanical load in the workpiece subsurface and the resulting α′-martensite content. It was demonstrated that increasing passive forces and cutting forces promoted the deformation-induced phase transformation, while increasing temperatures had an inhibiting effect. The feed force had no significant influence on the α′-martensite content. With the proposed models it is now possible to estimate the α′-martensite content during cryogenic turning by means of in-situ measurement of process forces and temperatures. | Impact of the thermomechanical load on subsurface phase transformations during cryogenic turning of metastable austenitic steels | 10.1007/s10845-020-01626-6 |
2021-03-01 | The device, the principle of operation and the test results of the apparatus for cryogenic freezing of oils designed to isolate impurities characterized by a high-melting state under atmospheric environmental parameters are considered. It was found that in the mode of extracting wax substances and phospholipids with an average rate of bubbling nitrogen vapor through an oil layer w = 2.2 m/sec, the best results for extracting impurities of wax substances and phospholipid compounds with a high-melting structure are obtained. At a higher rate of bubbling nitrogen vapor through an oil layer ( w = 2.5 m/sec or more), the freezing process is carried out with a high cooling rate, which adversely affects the nature of the high-quality agglomeration of high molecular weight impurities containing waxy and phospholipid fractions, and the final filtrate of frozen-out oil does not fully meet the requirements of the standard for physicochemical parameters. | Cryogenic Bubbling Purification of Vegetable Oils from Impurities | 10.1007/s10556-021-00859-3 |
2021-03-01 | Microstructure and mechanical properties in core of a carburizing 20CrNi2MoV bearing steel subjected to cryogenic treatment were investigated. Conventional treatment sample was quenched and tempered at 180 °C for 2 h. Cryogenic treatment samples were quenched, cryogenically treated at − 80 and − 196 °C for 4 h, slowly returned to room temperature and thereafter tempered at 180 °C for 2 h, and finally tempered at 180 °C for 2 h. The scanning electron microscope, electron backscattering diffraction, X-ray diffraction and transmission electron microscope were adopted for microstructure characterization. The results show that cryogenic treatment increases the fraction of high-angle grain boundaries and the precipitation of finely dispersed carbides in the matrix, decreases the volume fraction of inter-lath retained austenite, and hence improves the strength and hardness. Compared with the conventional treatment, the hardness, yield strength and ultimate tensile strength of the steel after cryogenic treatment are increased by 11.7%, 12.6% and 18.3%, respectively, while the impact energy is decreased by 9.8%. | Microstructure and mechanical properties in core of a carburizing 20CrNi2MoV bearing steel subjected to cryogenic treatment | 10.1007/s42243-020-00516-8 |
2021-03-01 | Although the performance of electronic devices in extreme temperature ranges has been extensively studied, the interconnections, which are still mainly Sn-based materials, require thorough observation and assessment to support the mechanical and electrical stability in subzero to cryogenic temperature environments. An in-depth assessment is required because of the nature of Sn, which has a ductile-to-brittle transition temperature of approximately −60°C. Sn-1Ag-0.5Cu (wt.%) (SAC105) solder joints were subjected to shear testing at room temperature and at −196°C at liquid nitrogen temperature. Isothermal aging at 150°C for 50–500 h prior to cryogenic temperature testing indicated further degradation under certain aging conditions. The study presented here investigates the maximum shear strength variations for SAC105 single solder joints with NiAu and Cu-organic solderability preservative (Cu-OSP) pad surface finishes using a multibond tester with a 10-μm shear height and 100-μm/s shear speed. An increase in the maximum shear strength was observed at liquid nitrogen temperature compared to that at room temperature due to an increase in the yield strength and loss in ductility of the solder material in response to the low-temperature environment. The maximum shear strength decreased with isothermal aging due to the crack propagation path variation. Fracture locations were identified between the Ni pad and the (Cu, Ni)_6Sn_5 interface for the NiAu surface finish components, and Cu-OSP surface finish solder joints revealed transgranular crack through the Cu_6Sn_5 and crack propagation between the Cu_6Sn_5 and the solder interface. The shift in the full fracture location is discussed in association with electron backscatter diffraction (EBSD) analysis on partially sheared solder joints at room temperature and at −196°C. | Impact of Cryogenic Temperature Environment on Single Solder Joint Mechanical Shear Stability | 10.1007/s11664-020-08456-5 |
2021-02-23 | The CERN cryogenic facilities demand a versatile, distributed, homogeneous and highly reliable control system. For this purpose, CERN conceived and developed several frameworks (JCOP, UNICOS, FESA, CMW), based on current industrial technologies and COTS equipment, such as PC, PLC and SCADA systems complying with the requested constraints. The cryogenic control system nowadays uses these frameworks and allows the joint development of supervision and control layers by defining a common structure for specifications and code documentation. Another important advantage of the CERN frameworks is the possibility to integrate different control systems into a large technical system with communication capability. Such a system is capable of sharing control variables from all accelerator apparatus in order to cope with the operation scenarios.The first implementation of this control architecture started in 2000 for the Large Hadron Collider (LHC). Since then CERN continued developing the hardware and software components of the cryogenic control system, based on the exploitation of the experience gained. These developments are always aimed at increasing the safety and improving the performance. To overcome the long-term maintenance challenges, key strategies such as the use of homogeneous hardware solutions and the optimization of the maintenance procedures were set up. They are easing the development of the control applications and the hardware configuration by allowing a structured and homogeneous approach. Furthermore, they reduce the needed manpower and minimize the financial impact of the periodical maintenance. In that context, the standardization of technical solutions both at hardware and software level simplify also the systems monitoring the operation and maintenance processes, while providing a high level of availability. | Control of large helium cryogenic systems: a case study on CERN LHC | 10.1140/epjti/s40485-021-00063-w |
2021-02-03 | Densities of two synthetic biomethane-like mixtures were measured in the homogeneous liquid phase and the supercritical region using a low-temperature single-sinker magnetic-suspension densimeter. Both mixtures consist of methane, nitrogen, hydrogen and oxygen, whereas the second mixture additionally contains carbon dioxide. For the first mixture, four isotherms from (100 to 160) K were studied over the pressure range from (1.5 to 6.6) MPa. The second mixture was investigated along three isotherms from (140 to 180) K at pressures of (2.6 to 9.0) MPa, where only the densities at 180 K are usable due to solidification of the carbon dioxide at the lower temperatures. The relative expanded combined uncertainty ( k = 2) of the experimental densities was estimated to be in the range of (0.022 to 0.027) % for the first mixture and (0.046 to 0.054) % for the second mixture, respectively. Due to a supercritical liquefaction procedure and the integration of a special VLE-cell, densities in the homogeneous liquid phase could be measured without changing the composition of the liquefied mixture. Moreover, saturated-liquid densities were determined by extrapolation of the experimental single-phase liquid densities to the vapor pressure, which was determined experimentally for the mixture without carbon dioxide and calculated with an equation of state (EOS) for the mixture containing carbon dioxide. The relative expanded combined uncertainty ( k = 2) of the saturated-liquid densities is less than 0.08 % in most cases. The new experimental results were compared with the GERG-2008 equation of state; the deviations are less than 0.17 %. | Density Measurements of Two Liquefied Biomethane-Like Mixtures over the Temperature Range from (100 to 180) K at Pressures up to 9.0 MPa | 10.1007/s10765-020-02791-9 |
2021-02-03 | This work focuses on developing the mathematical model of surface roughness (Ra) in the turning of Inconel 625 superalloy with cryogenically treated tungsten carbide inserts. The influence of cryogenic treated on the microstructure and hardness of tungsten carbide tools was also investigated for the as-received inserts and deep cryogenic treatment at − 196 °C for 12, 24, and 36 h conditions. Turning experiments have been performed according to an orthogonal array L16 with three parameters (cutting tool, feed rate, cutting speed) at different levels with a 1 mm depth of cut. The ideal cutting tool and cutting parameters were evaluated in terms of the surface roughness (Ra). Analysis of Variance has been applied to determine the percentage of each cutting factor. It has been observed that the cutting speed has a maximum with 66.28% contribution on Ra. The best optimal turning parameters are obtained as A3B3C1 according to S/N ration. The mathematical model of Ra has been developed by regression analysis. The developed model is tested with verification experiments and found to be in good agreement with the experimental results. | Optimization of Cutting Parameters Affecting Surface Roughness in Turning of Inconel 625 Superalloy by Cryogenically Treated Tungsten Carbide Inserts | 10.1007/s42452-021-04303-2 |
2021-02-02 | Chilldown of transfer lines is an important phenomenon associated with cryogenic liquid transfer from the storage facility to the location of its intended application. Analysis of heat transfer characteristics during cryogenic chilldown of a helical coil is the focus of this study. In view of the ease in availability and handling compared to other cryogens, Liquid nitrogen is adopted. The cryogen was transmitted through copper helical test sections with 7.94 mm outer diameter, 0.81 mm wall thickness and having helix angles 4°, 6°, 8°, 10°, 12° and 16° with horizontal axes, at three different mass fluxes, that is, 66 kg/m^2s, 86 kg/m^2s and 102 kg/m^2s under terrestrial gravity conditions. Temperature-time relationships were obtained and the results were compared with that of straight channels. The results of the experiment indicated that the chilldown time for coils of different helix angles were different at a given mass flux. Also, for a given helix angle, chilldown time varied inversely with mass flux. Results suggested the prospect of an optimum helix angle that can serve in minimizing the chilldown time, thereby reducing cryogenic liquid consumption. Finding correlations connecting heat transfer parameters in helical coils would enhance the scope of this study. | Experimental investigation on heat transfer characteristics in cryogenic chilldown of a helically coiled tube | 10.1007/s12046-020-01524-w |
2021-02-01 | Abstract Practical use of power transmission cables based on high-temperature superconductors (HTSC cables) can be accounted for by their high throughput. Despite the large number of HTSC cables, experimental ones and those operating as parts of existing networks, the issues of using high-current liquid-nitrogen-cooled three-phase HTSC cables for the transmission of high-power electricity from power plants remain poorly studied. The injection of alternating current into the cable system imposes a number of specific limitations in the design of current leads. Most superconducting devices are dc devices, and so there are almost no techniques for calculating high-voltage high-current ac current leads. This paper discusses the particularities of operation of ac current cryoleads and proposes the principles of their calculation that allow one to increase the active power transmitted through them. The sequence of determining the geometrical dimensions of supporting insulators of current leads, which determine the total length of current leads, is shown as a function of the external environmental conditions. The effect of heat transfer in a nitrogen gas medium on the thermal mode of the current lead has been considered. It has been established that the effect of cooling on the thermal mode of the current lead is much less than that of the heat release and heat distribution due to the relatively small specific heat capacity of gaseous nitrogen. The parameters of self-cooled copper current leads designed for 12 kA are considered at cooling temperatures of 65 and 77.4 K as an example. | Methods to Calculate the Current Leads of AC High-Temperature Superconductor Cables | 10.3103/S1068371221020115 |
2021-02-01 | Supercritical hydrogen storage tanks are one of the most promising hydrogen storage technologies. When liquefied hydrogen is pressurized by a cryogenic high-pressure reciprocating pump, supercritical hydrogen is produced. The most important element for supercritical hydrogen production is the management of the net positive inlet pressure (NPIP) of the cryogenic high-pressure reciprocating pump. This paper presents a numerical analysis model for predicting the NPIP of cryogenic high-pressure reciprocating pump systems using liquid nitrogen instead of hydrogen as a medium for the preliminary study of supercritical hydrogen production. An algorithm was developed to compute the pressure of a two-phase fluid in a cryo-reservoir, where boil-off gas is generated and liquid nitrogen is reduced via a pump. The waiting time to guarantee the initial pressure and the available time of the pump were simulated, and an available pump flow rate depending on the initial pressure has been confirmed. | Simulation study of pressure change between cryogenic reservoir and pump | 10.1007/s12206-021-0117-z |
2021-02-01 | Superalloys are difficult to process. For this reason, it is important to increase the surface quality of the material and reduce the tool consumption. In the present work, the shallow and deep cryogenically treated performance of cubic boron nitride (CBN) inserts in terms of surface roughness, tool wear, thrust force and chip formation under dry cutting conditions for finish turning of Hastelloy C22. The effect of CBN tools on cutting force, surface roughness, hardness and chip morphology was investigated by applying shallow and deep cryogenic treatment. With the surface roughness values obtained with the deep cryogenic-treated tools (DCT) tool, 137.1% and 73.8% improvements were achieved compared to the RT (Reference tools) and Shallow cryogenic-treated tools (SCT) tools, respectively. DCT and SCT tool were 31.58% and 5.5% lower than the cutting forces obtained with the RT cutting tools, respectively. According to ANOVA analysis, the most effective parameter affecting the surface roughness was determined as the feed with a 67.8% contribution. | Investigation of the Effect of Cryogenic Treatment Cubic Boron Nitride Turning Insert Tools | 10.1007/s11665-021-05453-5 |
2021-02-01 | The present work discusses the enhancement of mechanical properties, namely wear and impact resistance, of ultra-high molecular weight poly-ethylene (UHMWPE), exposed to cryogenic treatment under different conditions. The cryogenic temperature was found to play a vital role in the structure and properties of UHMWPE, whereas − 140 °C for a soaking period of 12 h was found to enhance the specific wear rate by 48% and 35% in dry and lubricated condition, respectively, while the impact strength increased by 175%, without hampering its structural stability. This finding contradicts the popular belief that a minimum 24 h of cryo-treatment at − 185 °C is essential to bring out the necessary changes in any polymer. Conversely, cryogenically treating the polymer at − 185 °C weakens and deteriorates the material, while lower temperature (− 80 °C) demonstrates to be insufficient to induce the desired cryo-structural modifications. The FTIR and XRD analysis revealed that the mechanical properties enhancement in UHMWPE is credited to the cryo-structural rearrangement of highly dense carbon backbone, which in turn reduces the inter-chain distance and brings the adjacent crystalline segments closer to each other, thereby increasing the crystallinity as well. | Structural Elucidation and Mechanical Behavior of Cryogenically Treated Ultra-High Molecular Weight Poly-ethylene (UHMWPE) | 10.1007/s12666-020-02140-2 |
2021-02-01 | An improved monochromatic radiation source with spectral width 4 nm based on a supercontinuum laser and double monochromator is introduced into a unit based on an absolute cryogenic radiometer in order to increase the precision of measurement of spectral sensitivity in the range 0.9–1.6 μm. A feedback system that supports stabilization of the power of monochromatic radiation with standard deviation 0.025% is developed. The power of optical radiation in the plane of the detector and/or power of the absolute cryogenic radiometer varies from 0.1 to 1.5 mW. The spectral distribution of the power of the newly developed source in different operating regimes of the supercontinuum laser is presented. | Monochromatic Radiation Source Based on a Supercontinuum Laser for Measurement of Spectral Sensitivity of Radiation Detectors in the Range 0.9–1.6 μm with the Use of an Absolute Cryogenic Radiometer | 10.1007/s11018-021-01870-z |
2021-02-01 | The accidental spilling of cryogenic liquid leads to formation of a spreading pool, which may result in pool fires, BLEVE(boiled liquid evaporate vapor explosion) or vapor cloud fire, such as liquefied natural gas, is flammable. The key aspect of evaluating the consequence of such a disaster is to predict vaporization rate of the spreading cryogenic liquid pool. In this study, an empirical function was established to predict the temperature gradient of concrete. Afterwards an improved 1-D heat conduction equation was established to predict heat conduction of the spreading cryogenic liquid, and then vaporization rate was measured. In addition, to validate accuracy of the improved 1-D heat conduction equation, small-scale experiments were conducted to calculate vaporization rate for a spreading cryogenic liquid pool. The resulting vaporization rate decreased with discharge time, and increased with spill rate. The established empirical function was used to predict the temperature gradient displayed satisfactory accuracy with absolute average relative errors (AAREs) less than 10%; the improved 1-D heat transfer model AAREs were less than 13% compared with the experimental value. In summary, the improved 1-D heat transfer model can be applied to predict vaporization rate if the spill rate and discharge time are confirmed. | Predicting the vaporization rate of a spreading cryogenic liquid pool on concrete using an improved 1-D heat conduction equation | 10.1007/s00231-021-03018-9 |
2021-02-01 | Manufacturing craves for more sustainable solutions for machining heat-resistant alloys. In this paper, an assessment of different cooling lubrication approaches for Ti6Al4V milling was carried out. Cryogenic cutting (liquid nitrogen) and conventional cooling (oil-based fluid) were assessed with respect to dry cutting. To study the effects of the main relevant process parameters, proper energy models were developed, validated and then used for comparing the analysed cooling lubrication strategies. The model parameters were identified exploiting data from specifically conceived experiments. The power assessment was carried out considering different perspectives, with a bottom-up approach. Indeed, it was found that cryogenic cooling, thanks to a better tribological behaviour, is less energy demanding (at least 25%) than dry and conventional cutting. If the spindle power is considered, lower saving percentages can be expected. Cryogenic cooling showed its best energy performance (from 3 to 11 times) with respect to conventional cutting if the machine tool perspective is analysed. Considering even the primary energy required for producing the cutting fluids, the assessment showed that cryogenic cooling requires up to 19 times the energy required for conventional cutting. | Energy assessment of different cooling technologies in Ti-6Al-4V milling | 10.1007/s00170-020-06575-1 |
2021-02-01 | In this paper, a new composite support made of steel and polymer is proposed for the internal supports of mobile cryogenic vessels. Multilayered design of the steel part in the presented support controls the heat transfer through this part by adding more thermal contact resistance (TCR) to the heat flow path. An analytical model is developed to calculate TCR between layers of the steel part at the support working pressure and temperature condition. A finite element (FE) model is also developed for the proposed support. Thermo-mechanical coupled and transient thermal analysis are performed on the FE model by ANSYS FE code to investigate heat transfer in the polymer and steel parts of the proposed composite support and a support made of polymer block. The effects of dynamic loading frequency and damping on the heat flux passing through the internal support are investigated for the new support design. Comparison of the heat flux results shows that the amount of heat transferred to the cryogenic tank through the internal supports decreases when using proposed composite design instead of polymer blocks not only in the static loading condition but also in the dynamic loading. | Investigating the effect of metal-polymer internal support on reducing the heat transfer rate of mobile cryogenic vessels | 10.1007/s00231-020-02950-6 |
2021-01-27 | The surface integrity of the material is the predominant necessity of a component to perform efficiently in varying working conditions. To improve the surface integrity of the workpiece secondary finishing processes are being performed. This work attempts to propose a realistic cryogenic slide burnishing condition for improvement of the surface integrity. The slide burnishing was performed by a novel slide burnishing tool on 17–4 precipitation hardenable stainless steel. The experiment was designed based on a central composite design. Initially, the effect of control parameters on the output response was examined by experimental analysis based on the design of experiment. Analysis of variance was used to analyze the influence of the variables on the performance indices. The regression technique was used to develop an empirical model. Optimization of process parameters for finding minimum surface roughness and maximum surface hardness was achieved by a multi-objective genetic algorithm. The optimized solutions were validated by performing confirmation experiments. | Influence of slide burnishing process on the surface characteristics of precipitation hardenable steel | 10.1007/s42452-021-04260-w |
2021-01-01 | Inconel 718 is widely used nickel-based alloy in engineering applications because of its favorable mechanical properties. Though, machining of this alloy is difficult and results in poor tool wear and surface quality. Selection of suitable machining condition is essential for improving the machining performance of this expensive and hard to cut the material. The study compares the use of cryogenically treated inserts in dry, MQL and cryogenic environment. Cutting speed, feed rate and depth of cut are considered as control parameters, whereas surface roughness and tool flank wear are the response parameters. The adequacy of developed response surface models (RSM) is tested on the basis of the correlation coefficient ( R ^2). Later, the effect of cutting parameters on surface quality and tool wear is presented for all three machining conditions. Application of liquid nitrogen with cryogenically treated inserts besides the use of MQL gives the least tool vibration, the lower cutting temperature during experimentation. Later on, the good surface quality of workpiece along with least tool wear is noticed. The performance curves show that the use of cryogenically treated insert along with MQL and liquid nitrogen is found to be better than other conditions. This is accepted as the best way for enhancing the machinability of Inconel 718. | Performance Appraisal of Cryogenically Treated Tool in Dry, MQL and Cryogenic Machining of Inconel 718 | 10.1007/978-981-15-3639-7_82 |
2021-01-01 | To understand the role of water in life at the molecular and atomic levels, the spatiotemporal distribution and interactions of hydration water molecules Hydration water molecule at the protein–water interface Interface , has been investigated using various types of biophysical methods. In this chapter, we describe experimental techniques and analyses necessary to understand the contents in the subsequent chapters. X -ray crystallography X-ray crystallography and electron microscopy Electron microscopy are used to visualize the static distribution of hydration Hydration water molecules Distribution of hydration wa-ter molecules in the interior and on the surfaces of protein molecules. Additionally, we focus on a spectroscopic method Spectroscopic method to address the temporal variation in the interaction between hydration Hydration water molecules and protein surfaces Protein surface . Molecular dynamics simulation Molecular dynamics simulation on proteins in an explicit water Explicit water system that provides molecular motions at a high spatiotemporal resolution Resolution facilitates experimental interpretation when using appropriate force field Force field parameters. | Biophysical Methods to Investigate Hydration Structures of Proteins | 10.1007/978-4-431-56919-0_2 |
2021-01-01 | The machining process of cryogenic treated composite materials is a challenging task and the process of machining these materials is treated to be an important technique among the manufacturing process. The present study involves the processing of Al6061-SiC composite material by stir casting process, wherein pre-heated SiC particles are added as reinforcement. The primary processed composites are subjected to cryogenic treatment and the mechanical properties, thermal properties are evaluated to study the influence of cryogenic treatment. The tests include the Hardness test, Impact test and Thermal Conductivity test. Results of the present investigation include improved mechanical properties in terms of hardness, improved thermal properties due to cryogenic treatment. | Effect of Cryogenic Treatment on Mechanical Properties of Al–SiC Composites | 10.1007/978-981-16-2086-7_6 |
2021-01-01 | Two high-precision gauges (Ø162-Go and Ø162-Not Go) for assessing shaft components with a nominal diameter of 162 μm were machined from SKD11 steel and heat-treated using some technologies, such as quenching, cryogenic treatment, and aging, to improve hardness, wear resistance, and dimensional stability. The hardness, abrasion intensity, microstructure, phase analysis, and change in size of the gauge were observed using a Metrolog hardness tester, the pin on disc abrasion equipment, Axiovert microscopy, X-Ray Diffraction X pert PRO, and 3D measurement FUSION 9106 machine, respectively. Results showed that the hardness of gauges is approximately 62 HRC after quenching at 1030 °C for 90 min and reduces to around (59 ÷ 59,5) HRC after applying heat treatment technology in M0 mode (quenching and aging at 150 °C for 48 h). The hardness of gauges is nearly (62.5 ÷ 63) HRC, which is 2 HRC higher than the value in M1 mode (quenching + cryogenic treatment at − 80 °C/6 h + aging at 150 °C/48 h), after deep cryogenic treatment at − 160 °C in M2 mode (quenching + cryogenic treatment at − 160 °C/6 h + aging at 150 °C/48 h) due to carbides formation. The gauge after heat treatment in M2 mode demonstrated the smallest change in size (ΔL < 3 μm) in the temperature range of 20 °C–40 °C compared with M0 and M1 modes. | Manufacturing and Heat Treatment of High-Precision Ring Gauge | 10.1007/978-3-030-69610-8_39 |
2021-01-01 | Cryogenic machining is a green manufacturing technique which eliminates conventional coolant use and related health issues. Present work optimizes cryogenic machining parameters by means of grey relational analysis in super-duplex stainless steel. The experiment is designed by means of Taguchi L_27 orthogonal array. The input parameters considered for the experiments are cutting speed(v), feed(f) and depth of cut(d), and output parameters are surface roughness value Ra, Rz and material removal rate (MRR). The experimental analysis is designed to minimize surface roughness and maximize MRR. The optimized results for better performance characteristics are cutting speed 240 m/min, feed rate at 0.1 mm/rev and depth of cut 1.5 mm. | Optimization of Cryogenic Turning Process Parameters Using Grey Relational Analysis (GRA) in Super-Duplex Stainless Steel (A479) | 10.1007/978-981-15-8704-7_38 |
2021-01-01 | The paper presents data on the synthesis of polymer composites based on a fluoroplastic matrix and ground titanium hydride. The possibility of mixing the initial components using cryogenic grinding has been studied. The uniformity of distribution of the filler in the polymer matrix was investigated by scanning electron microscopy. For comparison, composites were made in which the mixing of the components was carried out manually in an agate mortar. It is shown in the work that when using cryogenic grinding of components, their distribution is much more uniform than when manually mixing. It has been established that cryogenic milling will prevent the agglomeration of highly dispersed titanium hydride particles obtained during milling, ensuring high homogeneity of the polymer composite. Data on the mechanical properties of the obtained composites are presented. Annealing at 350 ℃ significantly increased the microhardness of all the samples under study. For pure fluoroplastic, this value increased by 35.7%, and for composites by 35.5% and 30.7% when using grinding in a mortar and cryogenic grinding, respectively. | Study of the Effect of Cryogenic Grinding on the Microstructure and Mechanical Properties of Polymer Composites | 10.1007/978-3-030-72910-3_39 |
2021-01-01 | SHE (Search for Habitable Exoplanets) is the first large infrared astronomical telescope project in China dedicated to searching for habitable exoplanets. The project goals are to complete the satellite and payload technologies research and system design and to test key performances of the telescope by developing a downsize prototype. The SHE downsize prototype is an optical space telescope of 50 cm clear aperture with three channels of spectrum ranging from 0.4 to 5 micron. The telescope is passively cooled and thermally controlled to a cryogenic temperature of around 60 K. This paper gives an overview of the SHE instrument optical, mechanical, and thermal design. | SHE: Design and Development of 60 K Telescope Downsize Prototype | 10.1007/978-3-030-56488-9_26 |
2021-01-01 | The present work deals with the influence of cryogenic coolants LN_2 delivered through holes made on flank surface and rake surface of tungsten carbide cutting tool inserts in turning of super duplex stainless steel (SDSS) using in-house developed cryogenic setup. Experiments were conducted with cryogenically treated tool, cryogenically treated tool with tempering, and cryogenic coolant directly passed through modified cutting tool insert. Results are compared with dry cutting conditions. The cutting conditions are low feed rate/high depth of cut, medium feed rate/medium depth of cut, and high feed rate/low depth of cut. The material removal rate and cutting speed are kept constant under all three cutting conditions. Microstructural study of the tool as received and cryogenically treated is examined using SEM. Population of harder tungsten carbide phase (gamma phase) is found to be more in cryogenically treated tool. Due to tempering, hardness of insert is improved by 8% which in turn increased tool life. Direct supply of LN_2 through modified cutting tool increased tool life by 23%, more than the cryogenically tempered tool. There are no appreciable changes in temperature of cutting tool under dry cutting and cryogenically treated inserts. However, there is a large difference observed in temperature of cutting tool when LN_2 is supplied through modified insert directly, which in turn yielded high tool life. | Experimental Evaluation of Cutting Process Parameters in Cryogenic Machining of Duplex Stainless Steel | 10.1007/978-981-15-4739-3_44 |
2021-01-01 | LM25-SiC metal matrix composites were manufactured by stir casting technique. The composites were welded by friction stir (FS) welding process. Experimental studies were carried out for specimens treated at different temperatures for FS welded composites, and pitting corrosion properties were evaluated. Mathematical models were developed to correlate welding process parameters to pitting potential. Excel solver software was used to optimize the pitting potential for FS welded MMCs. Composites reinforced with 10% SiC show maximum pitting corrosion resistance when treated at cryogenic temperature. FS welded MMCs show higher resistance to corrosion when processed at high temperature compared to MMCs of as-welded composites processed at cryogenic atmosphere. | Modeling, Optimization and Corrosion Analysis of FS Welded LM25-SiC MMCs | 10.1007/978-981-15-9809-8_63 |
2021-01-01 | Recent studies have reported the advantages of cryogenic machining in producing superior surface roughness ( Ra ) when applied in metal cutting. This study shows the application of Box-Behnken Response Surface Methodology (RSM) to analyze the effect of milling parameters; cutting speed, feed rate, axial depth of cut (DOC) and radial DOC on the Ra of Inconel 718 when machined at high speed using PVD carbide coated ball nose inserts. The experimental work was conducted under cryogenic condition using a new cryogenic CO_2 cooling system for efficient and consistent cooling at the cutting area. Experimental results revealed that the Ra was in the range of 0.114 to 0.197 μm, which far surpassed the calculated ideal Ra (0.28–0.78 μm) or that achieved by the manual polishing process (≈0.5 μm). Based on ANOVA, the dominant factor affecting Ra was cutting speed followed by axial DOC and interaction between cutting speed and feed rate. Meanwhile, the effect of radial DOC was relatively insignificant. By applying the quadratic model generated, the average error between the predicted and the experimental Ra was found to be 3.44%. Thus, the mathematical model is valid and acceptable to be used as a prediction model in this scope of study. This study also proves the effectiveness of cryogenic cutting using CO_2 to produce better surface finished. | Optimization of Surface Roughness in Cryogenic CO_2 Milling of Inconel 718 Using RSM | 10.1007/978-981-15-9505-9_37 |
2021-01-01 | Magnesium alloys Magnesium alloys have been used in the automotive and aerospace industry for several years, thanks to their high strength-to-density ratio. Their mechanical characteristics at room and even at elevated temperature have been well studied, whereas, when it comes to temperatures lower than room one, only a few studies are available in the literature. To this aim, the present paper investigates the mechanical behavior of AZ31 magnesium alloy Magnesium alloys sheets deformed at different temperature regimes. Tensile tests till fracture were carried out at room temperature, −100, −50, 100, and 300 °C using different specimen geometries in order to vary the stress triaxiality. The fracture strain values were identified making use of a combined numerical–experimental approach, whereas the fracture surfaces Fracture surface were qualitatively characterized by means of stereoscopy and scanning electron microscopy. Finally, the AZ31 fracture locus Fracture locus as a function of the stress state and temperature was constructed. | Temperature-Dependent Fracture Loci of AZ31 Magnesium Alloy Sheets | 10.1007/978-3-030-75381-8_130 |
2021-01-01 | The Cool down of move lines with the cryogenic liquids is a stream bubbling procedure having diverse warmth move regimes. In Cryogenic fuel move frameworks, high exactness numerical models are required for anticipating this two-stage stream bubbling procedure. The punishment of wasteful model leads into higher edge of structuring and working expenses. There has consistently been a drive to figure an all inclusive connection which can cover an expansive scope of liquids alongside the thermodynamic conditions for anticipating heat motion. These relationships anyway don’t cover cryogenic liquids explicitly for transient chill off bubbling of move lines. Consequently, the expectation of this investigation is to confirm these two-stage heat move connections for anticipating basic critical heat flux (CHF) against accessible stream bubbling information for cryogenic liquids. Cryogenic quenching trial test information is looked at against accessible relationships and the mean outright deviation in anticipating most extreme warmth transition from every connection is introduced. Results obtained through this work means that the current relationships are unequipped for precisely anticipating the size of warmth move during the procedure words. | Applicability of Empirical Correlations for Critical Heat Flux in Transfer Line Cool-Down Boiling | 10.1007/978-981-15-9853-1_39 |
2021-01-01 | Liquid air energy storage (LAES) has been regarded as a large-scale electrical storage technology. In this paper, we first investigate the performance of the current LAES (termed as a baseline LAES) over a far wider range of charging pressure (1 to 21 MPa). Our analyses show that the baseline LAES could achieve an electrical round trip efficiency (eRTE) above 60% at a high charging pressure of 19 MPa. The baseline LAES, however, produces a large amount of excess heat particularly at low charging pressures with the maximum occurred at ∼1 MPa. Hence, the performance of the baseline LAES, especially at low charging pressures, is underestimated by only considering electrical energy in all the previous research. The performance of the baseline LAES with excess heat is then evaluated which gives a high eRTE even at lower charging pressures; the local maximum of 62% is achieved at ∼4 MPa. As a result of the above, a hybrid LAES system is proposed to provide cooling, heating, hot water and power. To evaluate the performance of the hybrid LAES system, three performance indicators are considered: nominal-electrical round trip efficiency (neRTE), primary energy savings and avoided carbon dioxide emissions. Our results show that the hybrid LAES can achieve a high neRTE between 52% and 76%, with the maximum at ∼5 MPa. For a given size of hybrid LAES (1 MW×8 h), the primary energy savings and avoided carbon dioxide emissions are up to 12.1 MWh and 2.3 ton, respectively. These new findings suggest, for the first time, that small-scale LAES systems could be best operated at lower charging pressures and the technologies have a great potential for applications in local decentralized micro energy networks. | Liquid Air Energy Storage for Decentralized Micro Energy Networks with Combined Cooling, Heating, Hot Water and Power Supply | 10.1007/s11630-020-1396-x |
2021-01-01 | Abstract Soil studies were conducted in Southern Cisbaikalia. It has been established that climate and topography significantly affect the soil cover diversity and spatial distribution at the macro- and mesolevel. The complex geological structure, uneven age, and variety of bedrocks, as well as the composition and weathering degree of soil parent rocks, determine the distinct features of soils in the study area. As an example, the development of residual-calcareous brown forest soils is confined to outcrops of highly carbonaceous Cambrian rocks. At the microlevel, the soil cover structure is determined by the paleocryogenic Late Pleistocene microrelief. Its hummocky–pitted forms contribute to the differentiation of soil formation processes, thus, increasing the soil cover sophistication. Contrasting soil microcombinations are represented by complexes of automorphic autonomous soils on hummocky polygons and semihydromorphic heteronomous soils in cryogenic wedge-shaped structures (depressions). On hummocky polygons, the soil profile is formed in undisturbed ground masses, which is consistent with the postlithogenic soil formation type; while removals of the soil materials that occur on a regular basis indicate the denudation pedogenesis model. In depressions, the soil profile is formed in redeposited soil materials, while the presence of one or several buried humus horizons is consistent with the synlithogenic soil formation type and the accumulative–sedimentary (sedimentation) pedogenesis model. Based on the data collected in the course of this study, landscape and soil maps of Southern Cisbaikalia have been produced by interpolating the soil sampling points in the Quantum-GIS program with the application of landscape indication methods. | Soils of Southern Cisbaikalia: Diversity and Spatial Distribution Patterns | 10.1134/S1875372821010091 |
2021-01-01 | Large part of Russian territory (more than 60%) is located within permafrost zone. Cryogenic landslides and related phenomena in the permafrost zone are quite specific and include some types of slope processes that are absent in “warm” regions (e.g. block fields, very thin earth flows with diurnal cycle of activity, etc.). However, common types of landslides in the permafrost zone also have some specific peculiarities. The classification of cryogenic landslides and related phenomena is proposed. Compiling this classification, we considered both seven types of the frozen (permafrost) soil and six well-known landslide types. Role of the permafrost surface in the formation of the sliding surface was considered too, as well as the thermodynamic instability of the permafrost when temperature changes from positive to negative and vise-versa, which is a specific factor of slopes instability typical of the permafrost zone. Peculiarities of various types of the cryogenic landslides evolution and related phenomena at the territory of Russian Federation are described. | Classification of Cryogenic Landslides and Related Phenomena (by Example of the Territory of Russia) | 10.1007/978-3-030-60713-5_37 |
2021-01-01 | Ti-6Al-4V was machined by varying the nozzle position during external cryogenic CO_2 cooling. The thermomechanical load was measured and the resulting surface morphology was characterized. The results show a significant influence of the nozzle position on the temperatures in the surface layer. Furthermore, a correlation between the temperatures and the microhardness inside the surface layer of the workpiece was found. This relationship was used to specify an optimal positioning of the nozzle in order to minimize the occurring temperatures. | Influence of Nozzle Position during Cryogenic Milling of Ti-6Al-4V | 10.1007/978-3-662-62138-7_29 |
2021-01-01 | The cryogenic treatments improve fatigue life of tool and die steels. This work involves heating the H13 steel specimens to 1020 °C, quenching in oil thereafter double tempering at 520 °C for 2 h. Thereafter these specimens are subjected to minus 185 °C in a cryobath for 16 h and 1 h soft tempering at 100 °C. The nitriding was performed at 550 °C in the atmosphere of atomic nitrogen for 2 h to get the effective case depth of 200 μm. These specimens were subjected to rotating bending fatigue at constant amplitude with room temperature conditions at a speed of 3000 rpm. The H13 specimens were characterised for hardness, surface roughness and analysis of fractured specimens to investigate the improved fatigue life for cryogenically treated specimens. It was established that improved hardness, reduced surface roughness and moderate distribution of alloy carbides were accountable for the increased fatigue life for 16 h cryo-treated steel. | Performance Comparison of Nitrided and Cryogenically Treated H13 Steel in Rotating Bending Fatigue | 10.1007/978-981-15-4779-9_34 |
2021-01-01 | Nowadays, industries are facing problem to attain a good surface characteristic in hard-to-cut materials. The wire electrical discharge machining (WEDM) process is an advanced machining method which is highly advantageous in machining of superalloys with improved surface characteristics. Inconel 625 superalloy material has unique properties and is required for the aerospace, automobile and medical industry. This paper analysed the effect of significant process parameters, i.e. tool electrode (plain and cryogenic), current, pulse on time, pulse-off time, wire feed and wire tension on the surface roughness (SR) during the cryo-treated WEDM process. Taguchi’s L18(2^1*3^5) mixed orthogonal array was employed to conduct the experimentations. The significance coefficients were observed by performing analysis of variance at 95% confidence level. The tests were performed by using a different grouping of machining parameters. The effect of normal tool and the cryogenic tool was also investigated in present experimental work. | Performance Study of Surface Integrity of Inconel 625 by DoE Approach During WEDM Machining | 10.1007/978-981-15-4550-4_20 |
2021-01-01 | The article considers the issues of increasing the efficiency of cryogenic vacuum pumps to create a deep vacuum used in production processes during chemical and physical experiments. It is noted that the use of zeolites as a sorbent material, in comparison with activated carbons, provides a more efficient absorption of hydrogen and helium. It is proposed to increase the heat sink using compositions of zeolite and metal powders with high thermal conductivity, pressed onto the surface of the tubes. It is shown that the best results are achieved when using the composition of zeolite - copper powder. It is proposed to use the process of elastostatic pressing for the manufacture of coaxial-cylindrical samples. The original design of the pump with coaxial-cylindrical samples with the pressing of the sorbent composite layer is presented. The results of practical tests of the pump are presented. The prospects of using the developed adsorption cryogenic-vacuum pumps with sorbent elements based on zeolite and copper powders are considered. This research work was supported by the Academic Excellence Project 5–100 proposed by Peter the Great St. Petersburg Polytechnic University. | The Application of the Tubular Sorbing Elements Based on the Composition Powders of Zeolites in Adsorption Cryogeno-Vacuum Pumps | 10.1007/978-3-030-62062-2_21 |
2021-01-01 | The chapter presents studies regarding the tribological performance of composite materials and multilayer composite coated tools in manufacturing processes carried out by the authors. Two manufacturing processes were investigated—metal forming and metal cutting. In metal forming, the study aimed to explore lubricant-free forming utilizing multilayer DLC composite hard coating as the potential tool coating. The experimental studies on the coating include characterization of the coating, and tribological analysis of the coating using commercially available pin-on-disk, laboratory tribology simulative test and industrial ironing of stainless steel. In order to examine the influence of temperature and contact pressure along the tool/workpiece interface on friction, Finite Element analysis was performed. Meanwhile, in metal cutting, two environmentally benign machining techniques were investigated to determine their potentials in delaying tool wear progression. First, sustainable machining by coupling multilayer ceramic composite coated-tool with cryogenic coolant as the cutting fluid. Second, the machining of Carbon Fibre Composite and Titanium alloys stacks using Ultrasonic Assisted Drilling (UAD) technique. Both techniques include investigations on machining conditions with varied cutting tool speeds. The examinations on the experimental results were focused on temperature, tool wear, surface integrity and metallurgical structure of near-surface region. | Tribology of Composite Materials and Coatings in Manufacturing | 10.1007/978-981-15-9635-3_11 |
2021-01-01 | Abstract The 7075 aluminum alloy was subjected to deep cryogenic treatment (DCT) at –196°C with liquid nitrogen for different hours. The wear and corrosion behaviors of the alloy were investigated by hardness, friction and wear, intergranular corrosion (IGC), and electrochemical corrosion tests. The microstructure of the alloy was observed by transmission electron microscope (TEM). The results showed that both the wear and corrosion resistance of the alloy treated with DCT could be improved. After the DCT 12 h, the matrix precipitates of the alloy were fine and homogeneously distributed, and the grain boundary precipitates of the alloy were discontinued, so that the alloy performed better comprehensive properties. | Effect of Deep Cryogenic Treatment on Wear and Corrosion Resistance of an Al–Zn–Mg–Cu Alloy | 10.3103/S1067821221010144 |
2021-01-01 | The role of the electrode in electric discharge machining (EDM) performance is crucial because it has an impact on the geometrical accuracy, machining efficiency and surface finish of the machined components. In the present work, a new technical approach combining equal channel angular pressing (ECAP) and deep cryogenic treatment (DCT) was put forward to manufacture copper electrodes for enhancing the machining characteristics of electric discharge machining (EDM). Effects of the ECAP, the ECAP + DCT on the EDM performances including the electrode wear rate (EWR), the workpiece corner sharpness (WCS), the surface roughness ( R _ a ) and the surface characteristics of EDM workpieces have been investigated. The EWR after the ECAP and the ECAP + DCT was reduced to the minimum after two passes of ECAP. The EWR and WCS after the ECAP + DCT were less than that after the ECAP due to the higher hardness and electrical conductivity. The R _ a of EDM workpieces using electrodes processed by the ECAP + DCT was slightly less than that after ECAP. An analogous Hall–Petch relation between the R _ a of EDM workpieces and the grain size of electrodes was observed, indicating that ultrafine-grained electrodes processed by ECAP and the additional DCT would enhance the surface finish. The surface finish of EDM workpieces was discussed based on the features of the surface morphology. | Performance Evaluation of Electrical Discharge Machining using Ultrafine-Grained Cu Electrodes Processed by Equal Channel Angular Pressing and Deep Cryogenic Treatment | 10.1007/s11665-020-05351-2 |
2021-01-01 | Magnesium alloys are highly preferred for use in the automobile sector and aerospace industry because of their low density and superior strength. Due to the lightweight and high strength of magnesium alloys, they are continuously being used for engineering applications. The transport industry has benefitted a lot as weight reduction is of prime importance in terms of cost saving. AM60 magnesium alloy also has good resistance to corrosion especially when compared with the rusting of mild steel in the same atmosphere. The paper makes an attempt to determine the best machining conditions to manufacture magnesium goods, especially AM60 magnesium alloy. Drilling operation is carried out on AM60 magnesium alloy, and the results obtained are optimized using ANOVA technique. The output responses analysed are residual stress, thermal stress, surface roughness, maximum amplitude of vibration, deviation from concentricity, deviation from cylindricity, deviation from diameter and deviation from perpendicularity. These responses are analysed using ANOVA in order to check the productivity of drilling operation at controlled input parameters such as cutting speed, feed, time and drill bit treatment. Cryogenically treated drill bits with different tempering cycles are used as one of the input parameters. The input parameters are pre-defined and then applied in the drilling operation, and the corresponding results obtained are analysed. | Effects of Drilling Process Parameters Using ANOVA and Graphical Methods | 10.1007/978-981-15-8319-3_35 |
2021-01-01 | The availability of high-quality biological and environmental specimens for research purposes requires the development of standardized methods for collection, long-term storage, retrieval, and distribution of specimens. These practices require the implementation of a Certified Quality System specific for the Biobank (ISBER Biobank Proficiency Testing Program. https://www.isber.org/page/PTGI and BBMRI-ERIC Quality Management Services For Basic and Applied Research. https://www.bbmri-eric.eu/services/quality-management/ ). In parallel, the biobank infrastructure needs to be designed and implemented (OECD Best Practice Guidelines for Biological Resource Centres. http://www.oecd-ilibrary.org/science-and-technology/oecd-best-practice-guidelines-for-biological-resource-centres_9789264128767-en ; ISO/IEC 9001:2015 “Quality Management Systems requirements”. https://www.iso.org/obp/ui/#iso:std:iso:9001:ed-5:v1:en ; ISO 20387:2018, Biotechnology—Biobanking—General requirements for Biobanking. https://www.iso.org/standard/67888.html ; and ISO/TC 212 “Clinical Laboratory Testing and in vitro diagnostic test systems”. https://www.iso.org/committee/54916.html ) with state-of-the-art technologies, and with the objective to be operative for periods up to 20–30 years. The commitment of the institution is critical to achieving this goal. The technology which will be implemented (e.g., liquid nitrogen mechanical freezers, processing equipment, etc.) must be selected for present and future needs. Choices between manual and robotized equipment must be made, looking at future requirements, and considering the potential to improve the quality of the biobank. Backup systems (electrical and liquid nitrogen (LN_2)), remote back-up freezers, and sufficient space to expand are also mandatory for correct implementation and management of the biobank (OECD Best Practice Guidelines for Biological Resource Centres. http://www.oecd-ilibrary.org/science-and-technology/oecd-best-practice-guidelines-for-biological-resource-centres_9789264128767-en ). In this chapter, we describe the most important aspects of biobank engineering, as complementary to, or integral to, the information included in the international guidelines for design and implementation of a state-of-the-art biobank. | Biobank Design and Infrastructure: Biobank Engineering | 10.1007/978-3-030-55901-4_2 |
2021-01-01 | In this chapter, the general characteristics of permafrost and cryogenic features are described, and the degradation of permafrost is simply analyzed too. The permafrost in Mongolia lies at the southern edge of Siberian permafrost with different permafrost zones Zones . The distributions of continuous and discontinuous permafrost zones Discontinuous permafrost are usually controlled by the climate Climate in Mongolia while the local environmental factors are mean force that persist the existences of sporadic and isolated permafrost zones Zones . Due to the location and climate Climate condition, permafrost temperature Permafrost temperature in Mongolia is mostly close to 0 °C, and making it vulnerable to climate Climate warming and anthropogenic impacts. The results from permafrost monitoring indicate that permafrost in the country has degraded more intensively during the last decades and it has a negative effect on ecosystem Ecosystems services, because the permafrost in Mongolia overlaps considerably with forest and the source area of river water. In Mongolia, several features of cryogenic develop in the permafrost region, such as patterned ground forms, frost cracking, ice wedge, karst, thermokarst lake Thermokarst lake , aufeis, pingo, seasonal pingo, hummock Hummocks , frost heave, frost sorting, dog hole. | Permafrost in Mongolia | 10.1007/978-3-030-61434-8_7 |
2021-01-01 | Polytetrafluoroethylene (PTFE) is a typical material widely used in bearing, gaskets, gears, etc. of many various fields such as aeronautics, astronautics, and military. Traditionally, PTFE is manufactured by molding process, which is suitable for processing of large quantities and standard parts. And a deburring treatment is necessary after molding. For small-scale or special shape products, molding techniques require new molds which need long time period. In contrast, machining method can meet the requirements more efficiently. However, the traditional machining is prone to produce machining defects such as edge fins and burrs. In this paper, a novel and effective method for cryogenic machining is proposed. According to the experiment results, the cryogenic machining can effectively restrain the production of machining defects and subsurface damage layer. And the mechanism of defect suppression in cryogenic machining is revealed by analyzing the change of molecular structure and properties with temperature. | A novel and effective method for cryogenic milling of polytetrafluoroethylene | 10.1007/s00170-020-06332-4 |
2021-01-01 | The 26S proteasome is the most complex ATP-dependent protease machinery, of ~2.5 MDa mass, ubiquitously found in all eukaryotes. It selectively degrades ubiquitin-conjugated proteins and plays fundamentally indispensable roles in regulating almost all major aspects of cellular activities. To serve as the sole terminal “processor” for myriad ubiquitylation pathways, the proteasome evolved exceptional adaptability in dynamically organizing a large network of proteins, including ubiquitin receptors, shuttle factors, deubiquitinases, AAA-ATPase unfoldases, and ubiquitin ligases, to enable substrate selectivity and processing efficiency and to achieve regulation precision of a vast diversity of substrates. The inner working of the 26S proteasome is among the most sophisticated, enigmatic mechanisms of enzyme machinery in eukaryotic cells. Recent breakthroughs in three-dimensional atomic-level visualization of the 26S proteasome dynamics during polyubiquitylated substrate degradation elucidated an extensively detailed picture of its functional mechanisms, owing to progressive methodological advances associated with cryogenic electron microscopy (cryo-EM). Multiple sites of ubiquitin binding in the proteasome revealed a canonical mode of ubiquitin-dependent substrate engagement. The proteasome conformation in the act of substrate deubiquitylation provided insights into how the deubiquitylating activity of RPN11 is enhanced in the holoenzyme and is coupled to substrate translocation. Intriguingly, three principal modes of coordinated ATP hydrolysis in the heterohexameric AAA-ATPase motor were discovered to regulate intermediate functional steps of the proteasome, including ubiquitin-substrate engagement, deubiquitylation, initiation of substrate translocation and processive substrate degradation. The atomic dissection of the innermost working of the 26S proteasome opens up a new era in our understanding of the ubiquitin-proteasome system and has far-reaching implications in health and disease. | Structure, Dynamics and Function of the 26S Proteasome | 10.1007/978-3-030-58971-4_1 |
2021-01-01 | In this chapter, we present an overview of a standard protocol to achieve structure determination at high resolution by Single Particle Analysis cryogenic Electron Microscopy using apoferritin as a standard sample. The purified apoferritin is applied to a glow-discharged support and then flash frozen in liquid ethane. The prepared grids are loaded into the electron microscope and checked for particle spreading and ice thickness. The microscope alignments are performed and the data collection session is setup for an overnight data collection. The collected movies containing two-dimensional images of the apoferritin sample are then processed to obtain a high-resolution three-dimensional reconstruction. | From Tube to Structure: SPA Cryo-EM Workflow Using Apoferritin as an Example | 10.1007/978-1-0716-1406-8_12 |
2021-01-01 | In this work, 316L austenite stainless steels were fabricated by the selective laser melting (SLM) technique, and the as-printed samples were then treated by using two various routines, namely the intercritical annealing (IA) and the deep cryogenic treatment (DCT), respectively. Microstructural characterization, nanoindentation creep tests as well as tensile experiments were also performed on the achieved specimens to evaluate the effect brought by the various heat treatment routines. It is found that DCT treatment produces a finer microstructure with higher quantity of homogenous tiny precipitates, compared with the as-printed SLM and single IA counterparts. Such microstructure of the DCT specimen leads to a desirable indentation creep resistance at room temperature as well as a good mechanical performance on tension. In addition, applying a prior deep cryogenic treatment before the intercritical annealing brings more positive effects on the mechanical properties than only using IA. The result indicates that the DCT routine is definitely considerably beneficial for fabricating reliable metallic products fabricated by selective laser melting, and it provides an efficient alternative in real manufactures as well. | Effect of Heat Treatment on Microstructures and Mechanical Behaviors of 316L Stainless Steels Synthesized by Selective Laser Melting | 10.1007/s11665-020-05330-7 |
2021-01-01 | The article describes two main approaches to assessing the thermal loading of friction pairs—experimental and theoretical for evaluating friction pairs in terms of the phenomenon of fading. Most of the kinetic energy of a car with ABS is extinguished due to friction in the braking mechanism. Overheating of the brake mechanism, namely, its friction pairs, leads to the occurrence of critical fading, accompanied by a sharp decrease in braking torque. Reducing the influence of this phenomenon is a very difficult task both from the point of view of taking into account the cost of the brake mechanism and its minimal complexity. The authors propose the use of cryogenic treatment of brake discs to reduce the influence of thermal stress on the occurrence of fading, as well as comparing the results of theoretical and experimental evaluation of friction pairs of the brake mechanism. Modern methods of calculating temperature values and obtaining experimental data have been applied, allowing one to increase the accuracy of thermal load estimation. | Experimental and Theoretical Approach for Evaluation of Thermal Loading of Car Brake Discs | 10.1007/978-3-030-54817-9_94 |
2021-01-01 | Improving the tool life will increase the production by reducing the tool change time and tool cost. Various surface modification techniques are available such as commercial coatings method, cryogenic treatment, nitriding and cyaniding. The cryogenic treatment of the cutting tools enhances the micro-structural properties of the tool and used in increasing the tool life. In the present work, cryogenic treated tungsten carbide tool is used to examine the machinability characteristics on low-carbon AISI 1020 steel for turning operation. The experimental study on machining operations is conducted by Taguchi’s L9 orthogonal array for three levels with three factors. The governing parameters of cutting velocity, feed rate and depth of cut on tool wear rate and surface finish on the machined surface. The effect of each parameter on output response is verified through ANOVA. In that, the depth of cut is the most significant factor compared to other factors. The optimum machining condition is predicted through grey relational analysis. | Experimental Studies on Deep Cryo Treated Plus Tempered Tungsten Carbide Inserts in Turning Operation | 10.1007/978-981-15-4739-3_26 |