bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanocrystallinity Enhancement of TiO2 Nanotubes by Post-Hydrothermal Treatment
Authors: Yuwono Akhmad Herman , Sofyan Nofrijon , Kartini Indriana , Ferdiansyah Alfian , Pujianto Tego Hadi
Published: July 2011

In the present research, a modified post-hydrothermal treatment with different temperature of 80-150°C has been applied on as-annealed TiO2 nanotubes derived from conventional hydrothermal process. The treatment has two-fold objectives, i.e. enhancing the nanocrystallinity of anatase TiO2, and at the same time maintaining the integrity of nanotube structures. The resulting TiO2 nanotubes were characterized by using XRD and UV-Vis spectroscopy. The XRD analysis revealed that the as dried TiO2 nanotubes contain combined crystalline structures of sodium-titanate and anatase. It was also found that by increasing the post-hydrothermal temperature from 80 to 150°C, the nanocrystallinity of nanotubes enhances as indicated by increasing the crystallite size of anatase TiO2 from 6.93 to 7.81 nm. The anatase crystallite growth affected the optical characteristic of nanotubes, as represented with the reduction of the band gap energy, Eg from 3.75 to 3.67 eV by using Kubelka-Munk analysis for the obtained UV-Vis reflectance spectra. TEM observation confirms that the integrity of nanotubes structure can be well-maintained upon post-hydrothermal treatment.
The Effect of Multiaxial Stress State on Formation of Rafts in CMSX-4 Superalloy during Creep
Authors: Gebura Marek , Lapin Juraj
Published: July 2011

The effect of multiaxial stress state caused by a notch effect on microstructure degradation of single crystal nickel based superalloy CMSX-4 was studied during creep at a temperature of 950 °C, under constant nominal stress of 120 MPa for 500 and 1000 h. In order to minimize surface oxidation effects on microstructure degradation and notched geometry of specimens, all experiments were performed under protective atmosphere. The geometry of creep specimens was designed with the aim to obtain defined interval of principal stresses, which is sufficiently large to get reliable microstructure response during tensile creep experiments. Flat specimens with “U-type” notch were designed using elastic finite element method (FEM) calculations. Microstructure analysis of the crept specimens showed that notches affect degradation processes of the studied superalloy significantly. FEM elastic-plastic analysis was performed to simulate creep of the notched specimens. Material creep behaviour was integrated into calculations by a subroutine using equations derived from experimentally measured data for cylindrical creep specimens tested at various constant nominal stresses. Magnitude, distribution and orientation of principal stresses resulting from the specimen loading were calculated and their effect on formation of rafts was described.
Effect of Microstructure on High-Temperature Mechanical Behavior of Nickel-Base Superalloys for Turbine Disc Applications
Authors: Sharpe Heather J. , Saxena Ashok
Published: July 2011

The objective of this work was to establish relationships between alloy microstructure and high temperature mechanical properties such as strength, creep, and creep crack growth in Nickel-base powder metallurgy superalloys. Systematic variations of super solvus heat-treatments generated test material from three next-generation turbine disc alloys. Quantification of key microstructural features such as γ’ distribution and morphology and grain boundary serrations was coupled with mechanical testing results in order to optimize microstructure for operating conditions specific to the bore region.
Microstructure and Mechanical Properties of an Advanced Nickel-Based Superalloy in the as-HIP Form
Authors: May J.R. , Hardy M.C. , Bache M.R. , Kaylor David D.
Published: July 2011

This study evaluates the suitability of as-hot isostatically pressed (HIP) RR1000 for non-critical applications in aero-engine components. RR1000, an advanced powder nickel-based superalloy, was developed for disc rotor components in aero-engines. For these critical applications, the consolidated alloy powder particles are extruded to break down carbide and oxide networks, known as prior particle boundaries (PPBs), and to refine the structure into a fine grain size for isothermal forging. In this study, hot isostatically pressed compacts, made from two different powder particle size fractions have been assessed following heat treatments below and above the gamma prime solvus temperature. A microstructural evaluation shows a greater degree of PPB decoration occurs in the finer powder particle size fraction. Following a super-solvus heat treatment these PPBs pin grain boundaries of the fine powder particle size compacts, whilst the reduction of PPB decoration in coarse powder particle compacts allows significant grain growth. Tensile test results of as-HIP RR1000 show, good yield strengths, ultimate tensile strengths and ductility, which are comparable with extruded and isothermal forged RR1000 disc material. Dwell crack propagation tests show that finer powder particle size compacts, which have received a sub-solvus heat treatment, give the highest crack growth rates; whilst the remaining material conditions show markedly improved crack growth resistance. In conclusion, as-HIP RR1000 demonstrates clear potential for use in non-critical applications, employing either powder particle size fraction used in this study subject to the appropriate solution heat treatment.
Production of Net-Shape Static Parts by Direct HIPing of Nickel Base Superalloy Prealloyed Powders
Authors: Raisson Gérard , Guédou Jean Yves , Guichard Didier , Rongvaux Jean Marc
Published: July 2011

In order to reduce costs and increase the operating temperatures in aero-turboengines and space propulsion systems, net-shape or near net-shape production processes have been developed for static parts through HIPing (Hot Isostatic Pressing) of nickel base superalloys prealloyed powders. The presented results hereafter are related to the manufacturing processes and the mechanical properties (tensile, creep and LCF) characterisation. The effects of net shape surfaces and of surface conditioning have been investigated too. Examples of actual parts (CFM56 turbine casing and Vulcain rocket engine gas generator) illustrate the presentation. This study has confirmed the interest of this production route and future potential for development.
Superplastic Roll Forming of Axial Symmetric Articles from Superalloys
Authors: Utyashev Farid Z. , Mukhtarov Shamil Kh. , Nazarov Ayrat A. , Mulyukov Radik R.
Published: July 2011

A new method of microstructure design in axisymmetric gas turbine engine components made of superalloys is proposed. The method is based on obtaining three types of microstructures by means of superplastic roll forming: coarse-grained one with coherent nano-sized precipitates of the  phase, the second with ultrafine grains of both phases and the third combining coarse deformed matrix grains surrounded by thin layers of fine matrix grains and coarsened precipitates of  phase.
Study of the Turning Nickel Base Alloy Pyromet® 31V (SAE HEV8)
Authors: Ribeiro Marcos Valério , Habib Bahia André Luís
Published: July 2011

Considering the constant technological developments in the aeronautical, space, automotive, shipbuilding, nuclear and petrochemical fields, among others, the use of materials with high strength mechanical capabilities at high temperatures has been increasingly used. Among the materials that meet the mechanical strength and corrosion properties at temperatures around 815 °C one can find the nickel base alloy Pyromet® 31V (SAE HEV8). This alloy is commonly applied in the manufacturing of high power diesel engines exhaust valves where it is required high resistance to sulphide, corrosion and good resistance to creep. However, due to its high mechanical strength and low thermal conductivity its machinability is made difficult, creating major challenges in the analysis of the best combinations among machining parameters and cutting tools to be used. Its low thermal conductivity results in a concentration of heat at high temperatures in the interfaces of workpiece-tool and tool-chip, consequently accelerating the tools wearing and increasing production costs. This work aimed to study the machinability, using the carbide coated and uncoated tools, of the hot-rolled Pyromet® 31V alloy with hardness between 41.5 and 42.5 HRC. The nickel base alloy used consists essentially of the following components: 56.5% Ni, 22.5% Cr, 2,2% Ti, 0,04% C, 1,2% Al, 0.85% Nb and the rest of iron. Through the turning of this alloy we able to analyze the working mechanisms of wear on tools and evaluate the roughness provided on the cutting parameters used. The tests were performed on a CNC lathe machine using the coated carbide tool TNMG 160408-23 Class 1005 (ISO S15) and uncoated tools TNMG 160408-23 Class H13A (ISO S15). Cutting fluid was used so abundantly and cutting speeds were fixed in 75 and 90 m/min. to feed rates that ranged from 0.12, 0.15, 0.18 and 0.21 mm/rev. and cutting depth of 0.8mm. The results of the comparison between uncoated tools and coated ones presented a machined length of just 30% to the first in relation to the performance of the second. The coated tools has obtained its best result for both 75 and 90 m/min. with feed rate of 0.15 mm/rev. unlike the uncoated tool which obtained its better results to 0.12 mm/rev.
Influence of Chemistry on the Tensile Yield Strength of Nickel-Based Single Crystal Superalloys
Authors: Caron Pierre , Diogolent Frédéric , Drawin Stefan
Published: July 2011

The tensile yield strength of AM1 and MC-NG single crystal superalloys with a γ’ precipitate size close to 300 nm were compared within the 20-1050°C temperature range. The room temperature yield strength of the fourth generation MC-NG superalloy is about 200 MPa less than that of the AM1 first generation one. Inversely, at higher temperatures (T > 800°C), the tensile strength of MC-NG is higher than that of AM1. These results are discussed by taking into account the elementary deformation mechanisms and the respective strengths of the γ and γ’ phases. Experiments on a modified MC-NG alloy show that reinforcing the γ’ phase by increasing the contents of Ti and Ta is an efficient way to recover a higher tensile strength at low temperatures. Rhenium addition and increase of the γ’ solvus temperature are suggested to be beneficial for the high temperature tensile strength. Data published on various other single crystals are in agreement with these hypotheses.
Diffraction Profile, Strain Distribution and Dislocation Densities during Stage II Creep of a Superalloy
Authors: Dirand Laura , Jacques Alain , Chateau Jean Philippe , Schenk Thomas , Ferry Olivier , Bastie Pierre
Published: July 2011

One of the major ingredients of modelling the mechanical behaviour of superalloys is the knowledge of dislocation densities and strain distribution. Both can be measured using post mortem BF TEM and CBED, but such methods do not allow following their variations during a test. The aim of the present work is to investigate the usefulness of in situ X-Ray Three Crystal Diffractometry (TCD) to measure the density and distribution of dislocations within a rafted superalloy, i.e. during stage II of high temperature creep. As the instrument contribution is very low, the two-peaked experimental profiles are representative of the lattice parameter distribution within the material. The profiles were measured within bulk specimens at the BW5 high energy beamline Hasylab (DESY), during high temperature (1050°C to 1180°C) tests under loads between 0 MPa and 300 MPa. The peak shapes were observed to change with varying experimental conditions. The peak width follows different patterns under low and high stress, i.e. with low and high strain rates. The distribution of elastic strains was calculated by assuming two main contributions: dislocation segments trapped at the γ/γ’ interfaces in a more or less regular network, and dislocations moving within the γ’ rafts. A comparison between experimental and simulated peaks shows that several features of their behaviour can be explained: the absolute magnitude of the peak width, the observed decrease of the peak width under low loads with increasing interfacial dislocation densities. The larger increase in the width of the γ’ peak under high load (and strain rate) may be attributed to a dislocation density within the 1013 m-2 range within the rafts. The present results are presently being cross-checked by post mortem TEM observations.
Evaluation of Property Scatter of Nickel Base Alloy IN 738 LC
Authors: Linn Stefan , Scholz Alfred , Berger Christina
Published: July 2011

The nickel base alloy IN 738 LC is in use for gas turbine blades since more than 25 years. In high temperature creep testing the conventionally cast alloy exhibits a comparably large property scatter which requires high safety margins in design and dimensioning and subsequently causes an incomplete exploitation of the materials potential. The reasons for this property scatter were investigated and traced back to different influencing factors. Parallel to investigations on the microstructure of post-exposure material and conventional scatter band analysis, artificial neural networks were successfully applied to discover relations between the chemical composition of the individual melt and the position of the corresponding test results within the global scatter band. Recommendations for a lifting of the lower scatter band boundary and the mean curve are derived.
Development of New C&W Superalloys for High Temperature Disk Applications
Authors: Devaux Alexander , Georges Eric , Héritier Philippe
Published: July 2011

The enhancement of efficiency in gas turbine engines requires the development of new superalloys capable of withstanding higher temperatures. The development of novel industrial cast and wrought (C&W) disk alloys with required combination of strength, creep and fatigue resistances at 700°C is particularly desired due to the expensive cost of powder metallurgy. In this context, new C&W disk alloys were recently developed to fulfill these requirements. TMW4 shows higher properties than the current C&W disk alloy despite an expensive cost due to its high cobalt content, where as 718Plus presents a moderate cost with restricted creep properties at 700°C compared to the current U720Li disk alloy. The new nickel base superalloys developed by Aubert & Duval were therefore designed to offer a better compromise between high temperature properties at 700°C and cost. This paper describes the alloy metallurgical features and is especially focused on the alloy design which is extensively based on phase diagram modeling. The study was firstly carried out on small ingots of 6 kg to optimize the chemistry before forging 200 kg ingots by industrial processes. The ability to be processed by the conventional cast & wrought route and the control of the highly expensive elements contents confer to the alloys an attractive cost comparable to that of 718Plus alloy. The high amount of ’ and the molybdenum-tungsten levels insure higher creep and tensile properties than those obtained with 718Plus.
Hot Deformation Behaviors and Microstructure Evolution in a New PM Nickel-Base Superalloy
Authors: Tian Gao Feng , Zou Jin Wen , Wang Yu , Wang Wu Xiang
Published: July 2011

The hot deformation behaviors and the effect of flow stress on the microstructure were investigated for the as-HIPed and as-extruded materials in a new PM nickel-base superalloy. Under most test conditions, the as-extruded material exhibits superplastic flow because of grain growth corresponding to work hardening during deformation process, activation energy for deformation of which is 211 kJ/mol. However, activation energy of deformation for the as-HIPed material is 717 kJ/mol, because grain size is refined due to dynamic recrystallization, the reason being considered to be associated with the initial microstructure before the deformation. Based on the results of compression tests, two constitutive equations for the two materials were established using the mathematical regression; these will provide the valuable helps for predicting and controlling the deformed microstructure as well as optimizing hot-working process.
Undercoolability of Superalloys and Solidification Defects in Single Crystal Components
Authors: Ma De Xin , Wu Qiang , Bührig-Polaczek Andreas
Published: July 2011

The undercooling behaviour of the superalloys IN 939 and CMSX-6 during the isothermal heating and cooling processes was investigated. Under the same process conditions, the undercoolability of CMSX-6 was measured to be 50.4 K while that of IN 939 was only 10.1 K. This great difference can be attributed to the amount of alloying elements. During Bridgman directional solidification using the same process parameters, the used alloys exhibited a very different tendency to form structure defects. While the CMSX-6 components were nearly defect-free, the IN 939 samples of the same geometry were very prone to stray grain formation. This difference can be attributed to the different undercoolability of the investigated superalloys. Therefore, the undercoolability is an important factor of castability and the cast quality of single crystal components can be effectively improved by increasing the undercoolability of the superalloys.
Solidification Characteristics and as-Cast Microstructure of Rhenium-Containing Single Crystal Superalloys under High Thermal Gradient Directional Solidification
Authors: Liu Gang , Liu Lin , Zhao Xin Bao , Huang Tai Wen , Zhang Jun
Published: July 2011

A series of Ni-base single crystal superalloys with increasing contents of Re (3-6 wt. %) were directionally solidified under a high thermal gradient of approximately 250 K/cm. It shows that Re additions slightly increases the liquidus temperature, but decreases the eutectic reaction and γ′-solvus temperature of the experimental alloys. EPMA analysis indicates that Re addition strongly influences the segregation ratios of the constituent elements, particularly for Cr, Mo and W, and thus results in more severe dendrite segregation and large amount of eutectic formation in the as-cast microstructures.
A Study of the Weldability of Gamma Prime Hardened Superalloys
Authors: Schnell Alexander , Hoebel Matthias , Samuleson Jeff
Published: July 2011

Fusion repair processes such as gas tungsten arc welding (GTAW) and laser welding have been introduced for repairing turbine parts made from Ni-based superalloy materials. The weld-repair of turbine parts is well established, however, the inherent susceptibility of ’ hardened superalloys to weld cracking remains an issue and has resulted in repair limitations for highly loaded areas of turbine parts. This study presents a view of the weldability of superalloys taking both, the impact of the weld process and the weld filler selection into consideration. This comprises the interpretation of specific process parameters into physical parameters controlling the weldability and cracking sensitivity such as thermal gradient in the weld pool and solidification speed. Alloy specific parameters of the weld filler material, such as melting point and solidification interval are studied and set in correlation with the solidification parameters during welding.
Properties of Welded Joints on Superheater Coils Made from New Generation High Alloy Martensitic Steels Connected to Austenitic Creep-Resisting Steels and Supper Alloy Grades, for Supercritical Parameters
Authors: Pasternak Jerzy , Dobrzanski Janusz
Published: July 2011

The continuously developing power generation sector, including boilers with supercritical parameters, requires applications of new creep-resistant steel grades for construction of boilers steam superheater components. Therefore, this paper contains selected information, results of the research and implementation process including: - evaluation, comparison of requested properties of base material and welded joints, such as tensile strength, impact strength and technological properties, - destructive examinations with evaluation of welded joints and HAZ structure and hardness distribution, - influence of manufacturing process in large boilermaker conditions and after simulated operation. A new creep-resistant steels to be used, in order to comply with the operational requirements, as to assure the appropriate reliability and safety of the boiler equipment in operation process. This document presents a simplified analysis of martensitic steels from group 9-12% Cr (T91, T92, HCM12A, VM12) and austenitic steels Cr-Ni (TP347FG, SUPER 304H, HR3C), having the chemical composition as presented in tables 1 and 2, which are to be applied for steam superheater components.
Mechanical Properties of New Ni-Mn-Based Braze Alloys for the Fast Epitaxial Braze Repair of Single-Crystalline Ni-Base Superalloys
Authors: Laux Britta , Rösler Joachim
Published: July 2011

Diffusion brazing is a widely-used technology for the repair of cracks in hot section turbine components, mostly fabricated from single-crystalline Ni-based superalloys. Typically, braze alloys with a composition similar to the base material, enhanced by fast diffusing melting point depressants like B are used. If single-crystalline (SX) components are repaired, an epitaxial healing can be achieved, however, the filling of wide cracks in the range of 100-300 μm is difficult, since the process is completely diffusion controlled which means that wide cracks require very long hold times. If the temperature is lowered before a complete isothermal solidification has been awaited, the poor solubility of B in Ni leads to the precipitation of borides, serving as nucleation sites for stray grains. Thus, especially for the repair of wide cracks, new Ni-Mn-based braze alloys were developed which allow a very fast epitaxial healing. As B is replaced by Mn, the repair process can be significantly shortened since the epitaxial solidification is no longer diffusion controlled but can be enforced by cooling. This is due to the fact that Ni and Mn are almost completely miscible which means that the precipitation of secondary phases during solidification is eliminated. The Ni-Mn-based braze alloys were enhanced by Al, Cr and Ti to provide a sufficient high temperature strength and an appropriate oxidation behavior. Furthermore, heat treatment cycles have been developed producing a γ / γ’-microstructure very similar to the base material. In this work, results from mechanical testing of wide-gap samples which were filled with the new braze alloys are presented and discussed.
Evolution of the Diffusion Layer in a CMSX4 Single Crystal Superalloy
Authors: Gariboldi Elisabetta , Han Xing Hua , Longo Giulioantonio , Zanon Giovanni Paolo
Published: July 2011

Aluminising processes are well-known techniques industrially adopted to enrich of aluminium the surface layers of Ni-based alloys thus improving their resistance to environmental interaction at high-temperature. The results of aluminising processes are typically described in terms of the presence, compositions and thickness of the sequence of layers at the surface of the treated parts. Following this approach, the microstructural features of the diffusion layers obtained under different holding times via vapour-phase type high-temperature low-activity process were experimentally investigated on single crystal CMSX4 alloy. The attention was particularly focused on the effect of the crystallographic orientation of the crystal on the coating features. The evolution of the diffusion layers under different process conditions was then taken into account.
High-Temperature Oxidation Performance of Mo-Si-B Alloys: Current Results, Developments and Opportunities
Authors: Burk Steffen , Christ Hans-Jürgen
Published: July 2011

Ni-base superalloys are approaching the melting point as their fundamental limitation. For high-temperature components one possibility aiming at a further increase of efficiency, e.g. of jet turbines, is the use of refractory metals. Mo as base material is suitable for operating temperatures far beyond 1200°C. As a consequence of the formation of volatile Mo-oxides, it exhibits no intrinsic oxidation resistance when exceeding 700°C. Mo-Si-B alloys have melting points around 2000°C and retain good mechanical properties and oxidation resistance at very high temperatures. In air, the three-phase Mo-Si-B alloy dealt with in this paper shows excellent oxidation behaviour between 900°C-1300°C as a consequence of the formation of a protective silica scale. Below 900°C, alloys of this class suffer from catastrophic oxidation, leading to an evaporation of Mo-oxide and giving rise to a linear rate law of the weight loss. A protective oxide layer is not formed as a consequence of simultaneous and competitive Mo- and Si-oxide formation. Several approaches are possible to improve the oxidation performance of Mo-Si-B alloys, especially in this moderate temperature range. These include classical alloying, e.g. with Cr aiming for protective Cr-oxide scales, addition of small amounts of reactive elements for microstructure-refinement as well as selective oxidation of silica in oxygen-deficient atmospheres prior to operation in air. The results presented show promising opportunities and indicate that an oxidation protection from room temperature up to 1300°C requires a combination of the suggested approaches.
Lattice Misfit of High Refractory Ruthenium Containing Nickel-Base Superalloys
Authors: Neumeier Steffen , Ang J. , Hobbs R.A. , Rae Catherine M.F. , Stone Howard James
Published: July 2011

The influence of Ru, Co, Mo and W on the lattice misfit of eight highly alloyed Re containing single crystal nickel-base superalloys was investigated. High resolution X-ray diffraction (XRD) was used to relate the elemental partitioning behavior and the Vegard coefficients of the elements under investigation to the measured lattice parameter of the  and  phase. The residual chemical segregation and especially the coherency stress-induced tetragonal distortion of the  matrix lattice in the high Mo containing alloys results in the observation of two different lattice parameters for the  matrix phase. This leads to three overlapping, but clearly distinguishable {002} X-ray reflections.
Highly Soluble Poly (Aryl-Ether Benzoxazole) Random Copolymers by Aromatic Nucleophilic Polycondensation: Synthesis and Properties
Authors: Li Jin Huan , Wang Hai Yang , Wang Rui Hai
Published: July 2011

Aromatic polybenzoxazoles (PBOs) are very promising materials for civil, aerospace and electronics industries due to their outstanding mechanical properties, good thermooxidative stability and chemical resistance. However, the feasibility of the wide applications is hindered due to the difficulty of their processing derived from the very rigid structure. Poly(aryl-ether benzoxazole) random copolymers (PAEXBOx) were prepared by nucleophilic polycondensation. Ary-ether ketone and aryl-ether sulfone segments along with flexible linkages and bulky groups were introduced to provide PAEXBOx with good solubility in organic solvents. PAEXBOx exhibit the improved Tgs, and intermediate properties between pristine PBOs and poly(acryl ether)s (PAEs). The structure and properties of the polymers were systematically characterized.
Finite Element Analysis of Pipeline Steel Air-Bending
Authors: Li Qiang , Fan Li Feng , Gao Ying , Song Cong Hui , Yang Wen Tao
Published: July 2011

Air bending of wide-punch large radius of curvature, as a special bending mode, has been widely applied in the production of large diameter pipeline JCO forming. The JCO forming process is accomplished by several air bending processes. The quality and shape of pipe are greatly influenced by the air bending. During the present work, the bending is investigated into using the finite element (FE) method and orthogonal design of experiment. Experiments are carried out and the experimental result is very close to the result simulated by finite element analysis. Springback, forming force and residual stress are discussed. The aim of this research is to investigate the influencing degree of parameters, such as sheet material, sheet thickness, bending angle, lubrication and punch radius; in particular the effect of springback, forming force, residual stress on air bending parameters are also discussed.
Tribological Behaviors of Self-Lubricating Ceramic Tool Composite in Various Conditions
Authors: Cao Tong Kun , Ge Jun Peng , Yang Qi Long
Published: July 2011

Al2O3/TiC ceramic composites with the addition of CaF2 solid lubrication were produced by hot pressing. The effects of various conditions on tribological behaviors of Al2O3/TiC/CaF2 have been studied. The sliding wear tests against cemented carbide and 45 steel were performed on the ceramic composites using ring-block method. Results showed that with the increase of load and sliding speed, the friction coefficient decreased. However, the wear rate increased slightly with the increase of load and decreased with the increase of sliding speed. At low speed, the abrasion resistance of Al2O3/TiC/CaF2 coupled with cemented carbide was better than with 45 steel, while the abrasion resistance showed little difference at high speed. The friction coefficients were little different when coupled with cemented carbide and 45 steel respectively. During the sliding process, at the initial stage, the friction coefficient was waved because the self-lubricating film was not formed on the worn surface; after sliding 628m, the friction coefficient was stable because the self-lubricating film was formed on the worn surface.
Housing Die-Casting and its Process Based on Numerical Simulation
Authors: Huang Yong , Guo Ji Bin , Wu Qiong , Du Xiao Ming
Published: July 2011

Mould filling and solidification of aluminum alloy housing in die casting were simulated by the casting simulation software. Distribution and change of velocity field and temperature field were visualized. The optimized processing parameters were obtained with pouring temperature at 600°C and pre-heated temperature of mould at 180°C as well as injected velocity at 2.5m/s. The qualified aluminum alloy housing and the dense microstructure were successfully produced by adopting the optimized processing parameters, which is proved by the actual production.
Research on the ICP Acceleration Sensors Detecting Roadbed Compaction Degree Test
Authors: Cao Yuan Wen , Jiao Jian Hua , Ma Li Ying , Gui Shao Xiong
Published: July 2011

Compaction is an important influencing factor that makes various structural materials of road embankment and surface sufficiently dense, and it becomes more and more important that effective detecting methods of the compaction degree are employed to monitor the quality of compaction. In this paper, the testing methods and means that the compaction degree of sub grade soils was detected by the acceleration sensors during the compaction process of vibratory roller were presented, with which the field tests were performed to measure the acceleration of vibratory drum of the vibratory roller and the compaction degree of compacted soils, and then the relational expression between the vibratory acceleration and the compaction degree of soils were obtained. Results indicate that there exists such a significant positive correlation relationship between the virtual value of vibration acceleration and the soil compaction degree that the former can be used to characterize the latter accurately. Therefore, it provides a technical support for the development of nondestructive and live vibratory roller compaction degree detection technology.
Research on Six DOF Vertical Vibration Model of a Four Roller Hot Strip Rolling Mill Stand
Authors: Ma Wei Jin , Wang Jun Yuan , Li Feng Lan , Zeng Zhi Qiang , Xiao Deng Hong , Xiong Shi Bo
Published: July 2011

A lumped mass model with six degrees of freedom for the vertical vibration of four roller hot strip rolling mill stand was proposed, while its natural frequencies were calculated by MATLAB software. The numerical calculation results were proved more accurate through field vibration test. This vertical vibration model can be applied for dynamic simulation and structural dynamic modification with important theoretical and practical significance in mastering the vibration characteristics of four-roll mill, avoiding vertical self-excited vibration and improving production efficiency.
Measurement for the Damping Coefficient in Standard-Beam Balance Oscillating System
Authors: Tan Hong , Gao Jian , Li Shi Song , Li Zheng Kun
Published: July 2011

Damping coefficient is an important parameter in the system of swinging balance. There are various factors, such as knife hysteresis and the air resistance around the swinging balance, which influence the damping coefficient during the swing process. The energy of the balance and the amplitude of the oscillation will decay with time. It will stop swinging in numerable period. This damping phenomenon prevents us from measuring the oscillation period. So we need to analyse and study the damping coefficient. In this paper, we firstly analyse the working principle of the swinging balance, and then we measure the damping coefficient in different driving frequencies using experimental method and spectrum analysis. In the end, we get the evolution of damping coefficient under different driving frequencies.
Mechanical-Electronic-Hydraulic Integration: Light Load Linear Reciprocating Motion Device Having Variable Frequency, Displacement and Velocity
Authors: Zhang Ming Zhe , Wang Wei , Su Dong Ning , Zhong Kang Min , Sui Zhi Ming
Published: July 2011

The light load linear reciprocating motion device driven by a small-size pneumatic cylinder is most economical, but its velocity and location precision is not good. When substituting the drive for small-size hydraulic cylinder, the significant shortcoming is environmental pollution. If the motion is achieved through rolling screw-nut mechanism driven by stepping motor, the space layout is very inconvenient. A light load linear reciprocating motion device integrating mechanical, electronic and hydraulic technology is designed. In this device, the motion is achieved through short-stroke rolling screw-nut mechanism driven by stepping motor, and then amplified by a splendid internal reflux area effect stroke amplifier. This device has the following noticeable advantages: (1) The location of output hydraulic cylinder is as convenient as common pneumatic or hydraulic cylinder. (2) The frequency, displacement and velocity of reciprocating motion can be altered convenient by programming. (3) Higher position precision. (4) The hydraulic fluid in the device is enclosed, so there is no environmental pollution causing by oil leakage and volatilization.
Rotor Axis Orbit Monitoring Based on Virtual Instrument
Authors: Wei Yuan , Xu Wu Bin , Zeng Hai Jing , Zhang Hong Xian , Zhang Zhou Qiang
Published: July 2011

According to the typical rotating machinery faults and their corresponding rotor axis orbit characteristics, the using of eddy current sensor and the LabVIEW software platform constitute orbits measurement and analysis system, which is carried out for data acquisition, instrument control, measurement analysis and data display. The results show that orbits can be real-time display of motion, and two orthogonal vibration signals superimposed on the XY Graph.vi 'to generated the orbits and wave, calculating the quality of unbalance Block and the position of equilibrium rotor to make sure the system to reach equilibrium.
Research on the Describing for Products Information Evolution Based on TBS
Authors: Gan Yi , Zhao Ming , Zhang Zhi Wei
Published: July 2011

Based on the analysis of the product design and its process, by using Top Basic Skeleton (TBS) model as a link, and adopting eXtensible Markup Language (XML) to the product’s top-down design and the description of the information evolution, this paper defines the transfer process and the structure of the document of the information transfer in TBS modeling process, and describes the transmission of the design information layer by layer. As a conclusion, the combination of the TBS and XML is beneficial to control the product design process, and to do variant design.
Design Modeling and Solving Implementation for Product Conceptual Design in Quality Function Deployment
Authors: Yang Yan Hua , Zhu Zu Ping , Yao Li Gang
Published: July 2011

Considering the process of research in conceptual design, a framework model of Function-Behaviour-structure was put forward, and QFD was an effective tool for function conversion. Then a mixed solving technology combining case-based reasoning and behaviour solving reasoning was discussed to achieve design mapping. Finally, an automatic synthesis mapping system was developed and the conceptual design of clam collector was given as an example. Application results demonstrated that the proposed method was feasible.
Development of a Multi-Fingered Massaging Robot Hand
Authors: Han Liang , Tian Meng Qian , Chen Jin Zhong
Published: July 2011

This paper proposes a multi-fingered robot hand for the application of Chinese massage, which has a long history and is an important part of Chinese medicine. It is very helpful for human body conditioning and therapy. This research is about a new and feasible application of multi-fingered robot hand. The robot hand which has six degree of freedom (6-DOF) realizing 3translation-3 rotation (3T-3R) can automatically do the full massages process including pushing, picking-up and kneading actions to get the best therapy effect. In order to imitate a real human’s hand, we have designed four fingers for the robot hand. A single motor and connecting rod driving are chosen for fingers and closed-loop control is adopted for the robot hand by collecting and processing the signal of encoder and force sensor.
Research on Key Technologies of Manufacturing Resources Sharing Platform Supporting SMEs Based on Web Services
Authors: Wei Jun Ying , Zhong Pei Si , Guo Chun Fen
Published: July 2011

Manufacturing resources sharing is a strong support for the development of SMEs. By analyzing the development and current situation of SMEs, the function, architecture and the function model of the manufacturing resources sharing platform supporting SMEs are analyzed and established. The key technologies of the platform are discussed, such as the definition, classification, the information model, integration and the security management of the sharing manufacturing resources. The platform provides a strong support for the survival and development of the SMEs.
A Comparison between B4C-ZrB2-Al Composite and B4C-Al Composite on Microstructure and Mechanical Properties
Authors: Lü Peng
Published: July 2011

B4C-Al and B4C-ZrB2-Al composites were fabricated by infiltrating aluminum into porous B4C and B4C-ZrB2 preforms in vacuum. The effect of ZrB2 addition on the microstucture and mechanical properties of the B4C-Al composites were investigated. The flexural strength and the fracture toughness of composite improved greatly as the result of ZrB2 addition. The ZrB2 addition inhibited the reaction between B4C and Al. The infiltrated aluminum addition was the leading reason for the fracture toughness improvement of the composites. Inter/transgranular fracture mode with many tear ridges and dimples was showing in the fracture surface of the B4C-ZrB2-Al composite. The relationships between the microstructures and the mechanical properties of the B4C-ZrB2-Al composites were discussed.
How to Operate Energy-Saving Technologies of the Classroom in Hot Summer and Cold Winter Zone
Authors: Shi Wei , Du Jiang
Published: July 2011

Through the reconstruction project of teaching building in Huazhong University of Science and Technology, several effective and detail strategies of Energy-saving technologies has been researched for sustainable building in hot summer and cold winter area.
Analysis of Energy-Saving Design of Glass Curtain Wall in the Terminal
Authors: Liu Kui Xing , Zhu Neng , Tian Zhe , Wang Meng Lei
Published: July 2011

Airport Terminal has some unique architectural features, however, there is no design standard for Airport Terminal. In this paper, first, on the basis of researches and field tests, we make the dynamic load simulation using TRNSYS and analyze the characteristics of load of the Airport Terminal. We find the solar radiation has great impact on the building energy consumption. Second, we analyze the impact of sunshade and g-value on solar radiation. We find the L0 (L0=L/H) of southward should less than 0. 5, g-value should not be too small. Through this work, we hope to give a guide to the design of the Airport Terminal.
Ecological Design Strategies and Feasibility Analysis on Structure of Mobile Building in the Mountain Area
Authors: Cao Jun , Yu Jun Hua , Liu Yu
Published: July 2011

This paper explores some new methods of ecological design for mountain area buildings, which emphasize the features of portability and space flexibility. Based on the analysis of Qinling Mountain’s special environment, some new design strategies are explored, such as the ‘movable wall ’to meet the needs of changeable space, the flexible joint of members to meet the needs of portable assembly. Meanwhile，we explore some feasible structures for this design, and made the feasibility analysis on these structures. Conclusions for such exploration are made and further researches in the relevant areas are also recommended.
Study to Wood Electromagnetic Shielding Composites Laminated with Aluminum Plates
Authors: Lu Ke Yang , Fu Feng , Fu Yue Jin , Cai Zhi Yong
Published: July 2011

Radiations from different electrical devices cause electromagnetic interference which will influence the performance realization of other electromagnetic device and cause the health concerns. The aluminum plates were then used to develop wood electromagnetic shielding composites by laminating with the plywood. Their static modulus of elasticity and electromagnetic shielding effectiveness of the composites with different thickness and position of aluminum plates were evaluated. The results showed that the strength of composites were improved by laminating the aluminum plates on the surface. The electromagnetic shielding performance of the composites were increased by the design of the multilayer and sandwich shielding structure. Again, It was also found that the composites made by laminating two aluminum plates (1mm, in the middle or on the surface) had a better shielding effectiveness (60 dB to 92 dB, 60 dB to 106 dB, Ranged from 1 GHz to 10 GHz) and met the requirement for a commercial electromagnetic shielding building product.
Experimental Study on Flexural Deformation Behavior of Concrete Beams Reinforced with GFRP Bars
Authors: Fu De Cheng , Wen Yu Hui , Wang Bo
Published: July 2011

In this paper, the deflection of GFRP bars reinforced beams with different reinforcement ratio was studied, To research deflection of GFRP reinforced beam, four specimen beams were test under a four-point static load. The results indicate that deflection history of GFRP bar reinforced concrete beam is different with steel reinforced concrete’s, which has two stages: the linear part before crack and linear part after crack. The ultimate deflection decreases with the increase of reinforcement ratio.
Research on Residential District Energy-Saving Plan of Villages and Small Towns
Authors: Gao Bin , Zhou Yue , Li Hong , Huo Yu Ting
Published: July 2011

Making plan is the first step of construction. This article demonstrates and illustrates how to make residential district energy-saving plan of villages and small towns. We can make energy-saving plan through application of scientific and reasonable planning techniques of siting, layout, and renewable energy. We can construct energy-saving residential district under the guidance of plan. The popularity of this energy-saving plan mode will contribute a lot to the sustainable development and improvement of environment.
Not just Poetic - Timber Structure’s New Development in China
Authors: Wang Ping , Wang Dong
Published: July 2011

Timber structure has been thousands of years in China. But nowadays, the application of timber structure is almost blank. By analyzing present situation and problem in developing of timber structure in China by consulting bibliography and field research, we think the market potential of developing of timber structure in our country is very good. Analyzing advantages of timber structure and the condition of our country, We should do more research and solve the problem for the redevelopment of timber structure in China.
Administering and Comprehensive Utilization of Ash and Slag in Utility Hoiler
Authors: Bao Huai Qian , Wang Chang Tian , Zhang Ning
Published: July 2011

In order to the comprehensive utilization of enterprise resources, reducing environmental pollution, from point of view of governance and utilization of ash and slag in utility boiler, to discuss power plant boiler ash, slag, water-saving technological transformation, etc., it is designed to minimize water consumption and reducing pollutant emissions, and achieved good economic and social benefits.
Study on the Optimization of Depth-Span Ratio Design for Continuous Rigid Frame Bridge Girder
Authors: Sun Lei , Hao Xian Wu , Yang Ya Xun
Published: July 2011

By the force analysis of continuous rigid frame bridge girder, the depth-span ratio’s influence on the structure in load carrying was studied, the relationship between the depth-span ratio and prestressing force required by structure was established, and using the sectional force of girder in the construction and utilization of the bridge as the constraint, with the application of grid search method and the construction case of Ziyang bridge, we carried out the optimization of design on the depth-span ratio for continuous rigid frame bridge girder.
Forbidden of Polybromodiphenyl Ether Fire Retardant and Current Situation of its Substitutions
Authors: Zhang Xiao Ying , Wang Guo Hui
Published: July 2011

Environmental property of Polybromodiphenyl Ether and how it is restricted by Convention of Stockholm is introduced. Through the analysis of manufacture, application, current technique and substitution situation of Polybromodiphenyl Ether, the main problem of Polybromodiphenyl Ether Fire Retardant is pointed out, and suggestions of improvement is given in this paper.
The Hydrolysis of Gelatin and its Treatment for Waste Drilling Fluid
Authors: Wang Xue Chuan , Zhang Sha , Zhou Liang , Ren Long Fang
Published: July 2011

The most used flocculants in treatment of waste drilling water are PAM flocculants. But its polymeric monomer often has toxicity. Gelatin is a non-toxic, amphipathic natural macromolecule. The flocculants prepared by gelatin and its application in waste drilling water has not been reported. In the experiment, gelatin was extracted from chrome shavings. Sulfate, citric acid and trypsinase were chosen to hydrolyze gelatin and then collagen solution was obtain. Then NaNO2 was added to seal amino of the collagen molecules. The flocculation effects of collagen solution before and after sealing amino on waste drilling fluid was estimated by its CODcr removal rate and the concentration of suspended solids. The results indicated that after sealing amino, the flocculation effect on waste drilling fluid decreased obviously. And when trypsinase was used as hydrolytic agent, the treatment effect on waste drilling fluid was better. The optimal hydrolysis condition was: pH was 7~7.5, temperature was 37°C, reaction time was 3h and the dosage of trypsinase was 1.5% of the gelatin. Under this condition, the CODcr removal rate was 46.7% and the suspended solid content of waste drilling fluid decreased from 2607mg/L to 730mg/L.