bluuebunny/crossref_metadata_2025 huggingface dataset:
Therapeutic Targeting and Role of Cysteine Proteases in the Life Cycle of Malaria Parasite
Authors: Uddin Amad , Ara Anam , Thaer Abdulhameed Haider , Gupta Sonal , Arora Smriti , Singh Shailja , Abid Mohammad
Published: August 2024

The malaria parasite Plasmodium expresses four related papain-family cysteine
proteases. Targeting these different cysteine proteases can elucidate their roles and
potential as therapeutic targets, thereby expanding the pool of antimalarial targets. During
gametogenesis, cysteine proteases like SERA-5, SERA-3, DPAP-1, DPAP-2, DPAP-
3, and Falcipain-1 are required for parasitophorous vacuole membrane (PVM) rupture.
In the liver stage, cysteine proteases such as Falcipain-1 and SERA-3, SERA-4,
SERA-5, and SERA-6 are essential. Additionally, cysteine proteases like DPAP-3, Falcipain-
1, Falcipain-2, Falcipain-3, and SERA-5, SERA-6 play crucial roles in merozoite
invasion into red blood cells (RBCs), hemoglobin degradation, and merozoite release
from RBCs. This review summarizes the available literature describing the key roles of
various cysteine proteases in the life cycle of the malaria parasite and their potential as
targets for antimalarial therapy. Understanding these proteases could aid in developing
novel antimalarial treatments and overcoming drug resistance.
Metal Complexes with Schiff Bases - A Review of their Antimicrobial Activities
Authors: Nandini B. , Amutha Selvi M.
Published: August 2024

The multifaceted nature of Schiff bases and their metal complexes has garnered significant
attention in the realm of coordination chemistry. Schiff bases are flexible ligands that have
been frequently employed to form metal complexes via the nitrogen and oxygen atoms. This
unique interaction imparts distinctive properties to the resulting complexes, rendering them valuable
in various fields in catalysis, materials research, and bioinorganic chemistry. This comprehensive
review delves into the specific aspects of antimicrobial activities associated with Schiff
bases and their corresponding metal complexes. Understanding the interaction between Schiff
bases and DNA is crucial in elucidating their potential therapeutic applications. Additionally, the
antimicrobial activities underscore the diverse pharmacological implications of these compounds,
providing insights into their role in drug development and disease treatment.
Casticin: A Short Review on its Pharmacological Activity as an Anticancer Drug
Authors: Singh Sonia , Singh Bhoopendra , Semwal Bhupesh Chander
Published: August 2024

Casticin is a flavonoid that is derived from the Vitex species. Multiple studies have
investigated the anticancer properties of casticin against many types of cancer, such as bladder
cancer, breast cancer, oral cancer, lung cancer, and leukemia. Research has shown the ability of
casticin to inhibit cell growth and induce programmed cell death. The chemical exhibits efficacy
against numerous cancer cell lines through various molecular mechanisms. The substance hinders
the processes of invasion, migration, and proliferation and triggers programmed cell death by
multiple mechanisms, including the generation of reactive oxygen species and the dependence on
mitochondria. Additionally, it inhibits the cell cycle at different stages. These effects are achieved
by modulating several signaling cascades, specifically NF-κB, PI3K/Akt, FOXO3a/FoxM1, and
STAT3. This review provides a concise overview of the chemotherapeutic efficacy of casticin as
an anticancer drug.
Effect of Olivine, Barite and Calcium Carbonate on Cutting Carrying Capacity of Water-Based Drilling Fluids
Authors: Erdoğan Yasin , Kök Onur Eser , Özdemir Adil , Öztürk Sarper
Published: August 2024

Introduction:

In this study, the effect of different weighing material such as olivine, barite
and calcium carbonate on cutting carrying of water-based drilling fluids was investigated. Initially,
characterization studies were performed for the additive materials.

Method:

Then, spud type muds were prepared with bentonite and the weighing materials were
added at different rates ranging from wt.1-6%. After the sample preparation, mud weight, 600 and
300 rpm dial reading, plastic viscosity, yield point, flow behavior index and power law consistency
factor values were measured/calculated.

Result:

With these results, cutting carrying index of the muds was calculated and the effect of the
additive materials was compared. According to the results, it was determined that the barite added
muds had better cutting carrying capacity than others and the calcium carbonate added muds
showed worse cutting carrying capacity. Optimal CCI results were obtained from O-5 as 3.7869
and, from B-6 as 5.9417 and from C-4 as 2.7113.

Conclusion:

Results of this study show that olivine can be used as low additive ratios in drilling
muds to clean the hole.
Deposition of TiO2/Polymethylene Biguanide on Stainless Steel Wire for the Enhancement of Corrosion Resistance and Stability
Authors: Thirumal Kiruthigha , Sridharan Gokul , Ganapathy Dhanraj , Sundramoorthy Ashok K.
Published: August 2024

Background:

Orthodontic treatment relies on stainless steel (SS) wires to apply forces
and torque to reposition teeth. However, SS wires are susceptible to wear and corrosion in the
oral environment, necessitating improvements in their durability.

Objective:

This study explores the potential of a coating comprising titanium dioxide (TiO2) and
polymethylene biguanide (PHMB) to enhance the corrosion resistance of SS wires.

Methods:

SS wires were coated with a solution containing PHMB and TiO2 using a drop-casting
technique. Field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray
spectroscopy (EDAX), and electrochemical tests, including impedance spectroscopy and potentiodynamic
polarization, were conducted to characterize the coated wires and evaluate their corrosion
resistance.

Results:

FE-SEM, EDAX, and Emap analysis confirmed the presence and uniform deposition of
PHMB/TiO2 onto the SS wire surface. Electrochemical tests revealed that the PHMB/TiO2-
coated SS wires exhibited a significantly lower corrosion rate (7.08×10−6 mm/year) and higher
corrosion resistance (562466 Ω) compared to bare SS.

Conclusion:

The PHMB/TiO2 coated SS wire exhibited high corrosion resistance and offered
potential benefits for orthodontic treatments. Further research and optimization of this coating
may help to improve the durability and reliability of orthodontic appliances.
Malnutrition and Obesity in Patients with COPD Exacerbation, Insights from the National Inpatient Sample
Authors: El Labban Mohamad , El-Zibaoui Roba , Usama Syed Muhammad , Niaz Fayreal , Cohen Abbe , Krastev Peter , Khan Syed , Surani Salim
Published: August 2024

Background

The obesity paradox suggests that obese patients with Chronic Obstructive Pulmonary Disease Exacerbation (COPDE) may have better outcomes. COPD patients are at a higher risk of becoming malnourished, which has been linked to poor outcomes.

Objective

This paper aims to study the impact of malnutrition in patients with and without obesity hospitalized with COPDE.

Methods

Our retrospective study analyzed data from the National Inpatient Sample dataset between 2017 and 2020 to observe patients who were hospitalized with COPDE. The patients were divided into two groups: with and without malnutrition. The outcomes included all-cause mortality, invasive mechanical ventilation, length of stay, and total charge. We adjusted for confounders using multivariate regression model analysis.

Results

The study involved 392,920 patients with COPDE, out of which 5720 (1.45%) were diagnosed with malnutrition. Most of the patients in both groups were female, white, and under Medicare coverage. The mean age was higher in patients with malnutrition (67.6 vs. 64 years). In both groups, the rates of admissions were lowest in 2020 compared to three years prior. The rates and adjusted odds ratios of all-cause mortality were higher in patients with malnutrition (3.59% vs. 0.61%, P <0.01; adjusted odds ratio (aOR) 2.36, P<0.01, CI 1.8-3.7). We observed comparable findings when using invasive mechanical ventilation (13.2% vs. 2.82%, P<0.01, aOR 4.9, P<0.01, 3.9-6). Malnourished patients had a lengthier hospital stay and a greater total charge.

Conclusion

Malnutrition was identified as an independent risk factor associated with worse outcomes in obese patients admitted with COPD exacerbation.
Investigation of the Epidemiological Situation of Malta Fever in the Cities under Mashhad University of Medical Sciences during the years 2016 to 2022
Authors: Shokoufamanesh Ayuob , Daneshi Salman , Sarbisheh Iman , Estakhr Golnaz Peyravi , Niknam Noureddin , Raesi Rasoul
Published: August 2024

Background

Management of Malta fever disease requires policy-making and accurate epidemiological statistics and information.

Aim

The present study was conducted to determine the epidemiological status of Malta fever.

Materials and Methods

This study is of the secondary data analysis type, which was conducted using the recorded data of patients with brucellosis in the health center of Mashhad City from 2016 to 2022. Data related to 12,714 cases of brucellosis were analyzed using R software and Chi-2, Pearson, and independent t-statistical tests.

Results

The average age of the patients was 33.18 ± 18.81 years. About 87% of disease cases were related to rural areas and 13% to urban areas. The average annual incidence of the disease was 287 cases per 100,000 population at risk of the disease. The highest incidence rate was in 2020, and the lowest incidence rate was in 2016. The most cases of disease were related to the first three months of the year, and the least cases were related to the last three months of the year. Most cases of the disease were related to housewives, cattle breeders, and farmers.

Conclusion

The incidence of the disease increased from the beginning of the study to 2020 and decreased from 2020 to the end of the study. Health policymakers should integrate medicine, ecology, and education for the prevention and control of brucellosis. This holistic strategy recognizes the interconnectedness of human, animal, and environmental health, emphasizing the need for collaborative efforts across sectors to address the multifaceted nature of the disease.
A Comprehensive Review on Diverse Nanoparticle Formulations, Applications and A Concise Review on Nanomedicine in Cancer Therapy
Authors: Guvvali Dharmender , Mohanty Dibyalochan
Published: August 2024

The nanoparticle formulation technology is set to play a crucial role in the upcoming
years, significantly shaping the pharmaceuticals market, nanomedicine domain, and healthcare systems.
The success of employing nano crystallization strategies in industrial settings relies primarily
on the technique's capacity to create active pharmaceutical ingredient nanoparticles with precise
particle size, limited size variation, stability, consistency, large-scale feasibility, compatibility,
and cost-effectiveness. Using nano-particles as a technological advancement has allowed for
notable enhancements in various aspects. These include the substantial extension of product shelf
lives, augmentation of intracellular delivery for hydrophobic molecules, and the optimization of
specific therapeutics like anticancer agents, along with others.
As the importance of Nano formulations emerges in the market, nanotechnology has transformed
also in the field of cancer diagnosis and treatment. Nanoparticles, ranging from 1 to 100 nm in
size, offer unique advantages, including biocompatibility, decreased toxicity, improved stability,
enhanced permeability and retention, and precise targeting, making them an effective option for
cancer therapy.
This comprehensive review article delves into the various categories of nano-formulations. A brief
discussion on Nano medicine in Cancer therapy and different formulation strategies meticulously
examining their far-reaching influence on both the pharmaceutical industry as well as research centers
dedicated to Nano formulations.
Experimental formability evaluation for aluminium alloy sheets under hot stamping conditions
Authors: ZHANG Ruiqiang
Published: August 2024

Abstract. The process of Hot Form and Quench for aluminium alloys, known as HFQ®, has been developed and applied to manufacture lightweight, high-strength engineering panel components in the automotive industry. However, formability evaluation for the alloys under hot stamping conditions is challenging. In this study, a recently developed biaxial testing method has been applied to aluminium alloy AA6082 for formability evaluation at temperatures ranging from 440–510 °C and at a strain rate of 0.1 s-1. This method involves heating cruciform specimens via the resistance heating system in the Gleeble, and deforming them until fracture via a customised biaxial tensile rig which transfers a uniaxial force into biaxial forces. The location for welding thermocouples on cruciform specimen surface for temperature feedback control in the Gleeble is investigated. Furthermore, temperature nonuniformity within the gauge area of cruciform specimens is quantified, and biaxial tensile tests on the specimens are carried out under different conditions. Both the limit strains at the onset of necking and at fracture are determined, and their dependency on the deformation conditions is analysed. It is found that the biaxial testing method is applicable to AA6082 for formability evaluation under hot stamping conditions. In addition, the limit major strains vary with the strain state, but exhibit a minor dependency on the temperature in the range investigated.
Forming of lightweight helical gears by means of sheet-bulk metal forming
Authors: RECK Manuel
Published: August 2024

Abstract. A rising demand on resource efficient and highly functional products causes conventional metal forming processes to the reach their limits. For this reason, sheet-bulk metal forming (SBMF) for the production of thin-walled components with various filigree functional elements has been widely investigated in recent years. However, there is a research gap in the understanding of approaches within this process class for producing helical gears. These are in high demand in industrial environments due to their smooth running capabilities. In this study, a process combination of deep drawing and lateral extrusion for the production of helical lightweight gears is therefore examined. In the reference variant, the mild deep-drawing steel DC04 with a sheet thickness of t0 = 2.0 mm is formed with a 20° helical die. General process limits are derived depending on the die filling of the tool-side cavities. In addition, the influence of the gear angle on process and component target variables is analyzed and discussed.
Design and simulation of cross wedge rolling process for hollow motor shaft
Authors: HAN M.
Published: August 2024

Abstract. Nowadays, electric cars are experiencing rapid development, in which the production of motor shaft is one of the important parts. The cross wedge rolling (CWR) process is expected to be an efficient and material-saving production method for motor shaft production. Traditional motor shafts are manufactured by forging and machining, which inevitably causes material waste. While using the CWR method to produce the motor shaft, the forming accuracy can be improved, keeping the material performance. It’s possible to manufacture the hollow motor shaft billet directly and reducing the production cost greatly. Because of the asymmetric geometry profile of the motor shaft, the force is unbalanced during the forming process. The thermo-mechanical coupling finite element simulation is used to design and optimize the flat CWR tools. Then, the distribution of stress, strain, damage and temperature during the CWR process are analyzed. The traditional CWR process will easily cause central defects of the shaft such as micropores and voids. The hollow billet is used in the study. It helps to avoid such defects, also can be a new method to deal with the hollow motor shafts by CWR. Some disadvantages of traditional manufacture can be overcome.
Surface integrity analysis of 304 stainless steel after slurry blasting
Authors: CHAI Ze-lin
Published: August 2024

Abstract. The Eco Pickled Surface technology has attracted increasing attention due to its green and environmentally friendly characteristics. However, due to the complex internal structure of the oxide skin and the diverse bonding methods with the substrate surface, as well as the failure to establish a relationship between the substrate surface integrity and process parameters after descaling, the widespread application of this technology is restricted. The 304 stainless steel hot-rolled plates and strips had been researched in this article, and the finite element ANSYS/AUTODYN modules had been used to simulate the descaling process; An analysis was conducted on the surface integrity of 304 stainless steel after descaling, including roughness, residual stress, and corrosion resistance. The results showed that: The maximum temperature on the substrate surface under different abrasive particle sizes, blasting speeds, and blasting angles is 95℃;the impact range and depth of the substrate surface after slurry blast will increase with the increase of abrasive particle size and injection speed, The maximum hardened layer after slurry impact is 140 μm; The minimum corrosion current density on the substrate surface after slurry impact can reach 1.29*10-6A/cm2, the corrosion resistance of the substrate surface has been significantly improved, and the EBSD results show that the grains after slurry impact are concentrated in 4-19 μm, maximum 22 μm. The average grain size is 10.79 μm.
New evaluation method for cold-forge solid phase bonding of dissimilar metals
Authors: OKAMOTO Haruki
Published: August 2024

Abstract. Solid phase bonding is an effective method for joining dissimilar metals. Solid phase bonding is the bonding method without fusing metal matrix. Using this method, clad metal which is joined with sheet metals is in practice. However, the parameters to achieve stable cold-forge solid phase bonding in bulk are not well known. To investigate the parameters that affect the solid phase bonding state, a new test method to evaluate the strength of the bonding interface obtained by cold forging was developed. Using this method, test pieces bonded with S10C/A1070 and SUS304/A1070 were made in fluctuating interface bonding parameters (the surface area expansion ratio, the surface pressure). Although tensile test results showed large variation in joining strength at low value of bonding parameters, bonding was strong enough to exceed the A1070 base metal strength at the region of high value of bonding parameters. As it was found that the bonding parameters were able to measure the effect on joining strength in this experiment, it is considered that bonding parameters for solid phase bonding can be evaluated by the newly developed test method.
Concurrent Improvement of strength, formability and SCC resistance of Al-Zn-Mg-Cu alloy by hot stamping after rapid heating and re-aging on paint baking treatment
Authors: HIROSAWA Shoichi
Published: August 2024

Abstract. In this study, the combined application of rapid heating for hot stamping and the subsequent re-aging during a paint baking treatment was newly developed for T6-tempered A7075 Al-Zn-Mg-Cu alloy sheets. From a systematic investigation, rapid heating to 255-260 ℃ and short-time holding for ~120 s was found to give the best combination of formability, hardness and stress corrosion cracking (SCC) resistance of the final products. In particular, re-aging treatment at 170 ℃ for 1.2 ks was well exploited not only for further improvement of SCC resistance but also for rebound of the decreased hardness by rapid heating. Therefore, the developed three-step heat treatment is regarded as a promising approach to producing high-strength, easily formable and corrosion-resistant Al-Zn-Mg-Cu alloy parts for automobiles.
Contour precision controlling of welding distortion in fabrication for stainless steel hyperbolic shells adopting mechanical constraints
Authors: ZHAI Hua
Published: August 2024

Abstract. Double-layer shell structures are widely used in the carapaces of vacuum vessels, cyclotrons, submarines and ships. The design of this double-layer structure considers the structural strength, sealing and special conditions. In the shell processing, the crisscross ribs are welded with the inner and outer shells to become parts. The welding deformation caused by multiple joints exceeds the tolerance, and external constraints are needed to ensure the forming accuracy of the contour. In this paper, the suppression effect of fixture and rigid constraint method on welding deformation of butt joint and T-joint was analyzed. The welding specimen of the double-layer shell structure was carried out, and the influence of different welding sequences on the final welding deformation was analyzed. Through external mechanical constraints, the deformation is reduced from 7.27 mm to 2.89 mm, which meets the tolerance requirements. The measured deformation is compared with the simulation results based on the inherent strain theory, which verifies the reliability of the numerical model and provides technical guidance for engineering manufacturing.
Study influence of forming process on microstructure and properties of deep hole thick wall pipe blank
Authors: LEI Bingwang
Published: August 2024

Abstract. According to the demand for high strength and high toughness of deep hole thick wall pipe blank, basing on 36,000 tons of vertical extrusion machine, 3,000 tons of free forging press and 1,600 tons of radial forging machine. Using electroslag remelting to smelt Cr-Ni-Mo-V steel ingot as raw material, three forming processes were studied, including free forging and radial forging, solid extrusion and radial forging, and hollow extrusion and radial forging. The physical quantity distributions of stress, strain and strain rate in the deformation zone of billet blank in different forming processes were analyzed via numerical simulation technology. Combined with the numerical simulation results, three forming processes were carried out in engineering trial production. The trial production results show that the structure of the pipe blank produced by the hollow extrusion + radial forging process is uniform, the mechanical properties of the pipe blank at both ends of the sampling RP0.2≥1370 MPa, -40°CKV≥28.0J, the mechanical properties of the full-length cross-section of the pipe blank RP0.2≥1381 MPa, -40°CKV≥28.2 J, the full-length yield strength is 28 MPa, and the comprehensive performance level is leading in the world.
Reduction of springback of Ti6Al4V alloy in ultrasonic vibration assisted deformation: Numerical simulation and experimental study
Authors: GAO Meng
Published: August 2024

Abstract. The ultrasonic vibration assisted bending tests of Ti6Al4V are conducted under different forming temperatures and vibration amplitudes. The effects of forming temperature and vibration amplitude are investigated. Moreover, based on ABAQUS software and explicit solver, the ultrasonic vibration-assisted bending deformation process is simulated to explore the influence of temperature and amplitude on the springback of the plate. The results show that the springback of the plate decreases with the increase of vibration amplitude. Increasing the temperature can also reduce the springback of the plate. At 1000°C, increasing the amplitude shows the best effect on reducing the springback of the plate. The finite element simulation results show that increasing the amplitude can reduce the stress in the central deformation area and makes the stress distribution uniform. The increase of temperature reduces the overall deformation stress of the plate, thereby reducing the springback of the plate.
The effect of web tension on calendering wrinkles and corrugations of coated foils
Authors: FU Zejun
Published: August 2024

Abstract. Lithium-ion batteries have been widely used in energy storage for a range of applications from portable electronics, electric vehicles to power grids due to their high energy density, high power density and long cycle life. Calendering is a critical process in the manufacturing of lithium-ion batteries electrodes, which has a significant influence on volumetric energy density, long-term cycle stability, and electrochemical performance of lithium-ion batteries, etc. Wrinkles in the uncoated area and corrugations in the coated area of the electrode during the calendering process are serious problems in the industrial production of lithium-ion batteries, as shown in Fig. 1. Adjusting the web tensions has been a critical solution to mitigate these defects. However, large web tensions often lead to foil tearing, severe wrinkles, and high scrap rates, due to a lack of understanding of the wrinkling and corrugating behavior under different tension conditions. To cope with that, this stuedy aims to investigate the mechanism of wrinkling and the effect of web tension on the wrinkling of electrodes during calendering. Calendering experiments are carried out for lithium battery cathodes under different front and back tensions and the three-dimensional topographies of calendered electrodes are measured by a laser profiler. The corrugations of electrodes can be improved by the difference between the front and back tension, instead of the magnitude of the tension, and the tortuosity is reduced by 34.2% at a tension difference of 20 N, compared to that of 5 N. An increase of the tension difference leads to a linear increase of shear displacement δ, causing severe wrinkles in the uncoated area of electrodes. An analytical prediction model for the wrinkles during calendering is established based on shearing of the rectangular membrane and an electrode quality evaluation method for balancing wrinkles and corrugations is proposed. The determination of optimal web tension settings, with a tension difference of 17 N, is achieved to obtain the best quality calendered electrodes, which is in agreement with the experimental results. The method presented in this paper is helpful for the improvement of the production quality and efficiency of lithium battery electrodes.
Deformation laws and design method of near-net rolling for L-section rings with profile axial conical rolls
Authors: QIAN Dongsheng
Published: August 2024

Abstract. L-section rings are widely used in key basic parts, such as flanges and rotary supports. When the radial length of the ring step is large while the axial depth is shallow, traditional ring rolling with profile mandrel may result in forming defects such as incomplete filling of the steps. This paper proposes a near-net rolling technology for L-section rings with profile axial conical rolls. Firstly, a finite element model for the rolling process of L-section ring was established. Then the revolution laws of the ring geometric dimension and the metal flowing behavior during the rolling process with profile axial conical rolls were studied. Further, the influence of key process parameters on the forming effects was revealed, including radial-to-axial deformation ratio, rolling ratio, and roller motion. Finally, the feasibility of the proposed process method was verified by FE simulation and rolling experiments. The research results provide a technical guidance for the near-net rolling forming of L-section ring, contributing to the high-performance, efficient, and cost-effective manufacturing of parts like L-section flanges and rotary supports.
Effect of surface characteristics on strain distribution in air- bending
Authors: KAIJALAINEN A.
Published: August 2024

Abstract. This study is a continuation of previous studies; therefore, the idea is to determine the influence of surface roughness and hardness on the bendability of a UHSS grade, and it is investigated with 3-point bending tests, utilizing Digital Image Correlation (DIC) for measuring the strain distributions on the outer curvature. Investigated bending samples of a 4 mm thick commercial bainitic-martensitic steel sheet were tested in different surface conditions: (1) as- rolled, (2) dry electropolished, (3) ultrasonic burnishing and (4) a combination of dry electropolishing and ultrasonic burnishing. Ultrasonic burnishing increased the surface hardness and decreased the surface roughness. Bending results showed that smoother surface did not lead to improved bending angles and higher hardness in the subsurface decreased the bending capacity, i.e., reduced the maximum bending angle and critical strain.
Hole expansion performance of a medium manganese advanced high-strength steel after hot rolling and intercritical annealing
Authors: PLOSILA Pekka
Published: August 2024

Abstract. This paper investigates the hole expansion behavior of a medium manganese advanced high-strength steel. The study began with vacuum-cast 0.3C–1Si–6Mn–2Al steel, which was subsequently laboratory hot-rolled to a thickness of 4 mm. Intercritical annealing treatments (IAT) were then carried out at temperatures of 650 °C and 700 °C to produce varying fractions of tempered martensite/ferrite and retained austenite (RA). Tensile tests were performed in the longitudinal direction, while hole expansion tests following ISO 16630 were conducted to assess the stretch-flangeability of the IAT materials. Test holes were prepared using punching and wire electrical discharge machining (W-EDM) to examine the effects of different edge conditions. Tensile strength of 1027 MPa and 911 MPa corresponding to a microstructure consisting of RA fraction of 7.5% and 43.3% were obtained at IA temperatures of 650 °C and 700 °C, respectively. Mean hole expansion ratios (HER) with punched holes were relatively low for the given strength levels (3% and 17% for IAT 650 °C and IAT 700 °C, respectively). W-EDM edge condition considerably improved HER but not as much as expected, potentially due to the high inhomogeneity of the microstructure. Further research on optimization of processing and microstructure is required to enhance the poor hole expansion performance of intercritically annealed medium manganese steels.
Development of X40CrSiMo10-2 steel series for heavy-duty in hot environment of marine diesel engines
Authors: EL-BITAR Taher
Published: August 2024

Abstract. Different X40CrSiMo10-2 Steel series are developed to serve as a heavy-duty exhaust valve for marine diesel engines. The alloys contain 0.35-0.50 % Carbon combined with 8.5-10.0 % Chrome, 2.0-2.5 % Silicon and 1.0-1.3 % Molybdenum. The steel series were processed in an induction melting furnace and cast as round cylinders with 105 mm mean diameter, and 360 mm height. Melt steel was bottom poured with 27 mm average diameter runner. Each Cast ingot was weighting 26.5 Kg. The thermodynamic calculations ensured formation of strong-stable Cr-Mo carbides containing Cr23C6 and Mo2C at the specified working temperatures. Cr enhances oxidation resistance of the alloy, while Si besides Cr are working to secure a ferrite phase matrix at room temperature and up to Ac1(855 oC). On the other hand, Mo beside the strengthening effect, it is fighting against coagulation of carbides within the matrix during working in the hot environment. A microstructure of the as – cast condition exhibits coarse ferrite grains due to slow rate of cooling during solidification in the sand mold. Cr and Mo- carbides are precipitated as thin layers enveloping the solidified ferrite grains, while the majority of carbides are precipitated as clusters scattered over the grains. On heating the steel to a temperature higher than Ac1, considerable portion of the ferrite matrix is transformed to austenite phase and the scattered carbides are then dissoluted. Multi-step hot forging is a complementary process, where the matrix would be finer with homogeneously distributed embedded carbides. Forging would be carried out by 5- successive controlled steps to obtain 50 mm diameter round bars.
The role of thermomechanical processing in controlling the microstructure inhomogeneity as a way to create special properties of (FeMnNiCo)1-x Mox high entropy alloy - a practical approach
Authors: CICHOCKI Kamil
Published: August 2024

Abstract. From modern alloys, increasingly demanding combinations of properties are expected, enabling their use as structural materials in new areas of application such as the energy industry (Liquid Natural Gas and hydrogen tanks), military, or space. One of the fundamental expectations for constructional materials used in these sectors is high energy absorption capacity while maintaining high strength (often at low temperatures where e.g. conventional steels exhibit brittleness). Simultaneously, they require appropriate plastic deformation susceptibility (formability) and other additional parameters (e.g., corrosion resistance, weldability, fatigue resistance). Designing manufacturing technologies for the metal forming of structural elements from modern engineering materials for the aforementioned applications requires a holistic approach and understanding of the relationships between process parameters (time, temperature, deformation, strain rate), microstructural phenomena (recovery/strengthening mechanisms, phase transformations, precipitation processes), and resulting properties (strength, ductility, toughness). In this work I will provide a practical example of designing specific properties of (CoNiFeMn)1-xMox high entropy alloys by controlling microstructure development at each stage of the metal forming process. The role of recrystallisation, grain growth, and the precipitation of the phase in controlling grain size - a key parameter defining the susceptibility to twinning/nanotwinning in this alloy at cryogenic temperatures - will be discussed.
Semisolid deposition of metallic material by extrusion-base analytical and simulative methodologies
Authors: BRUNI C.
Published: August 2024

Abstract. The objective of the paper is the analytical and finite element simulation study of the material behaviour at temperatures of 400 - 450°C of AZ31 and ZM21 magnesium alloys tested for bulk metal working. In the extrusion, representing the main phase of the fused deposition modeling, the metal work material considered was a bulk magnesium alloy billet. The stress and deformation fields are reported in detail using analytical modeling to describe the material in a very small volume of a extruder. It is observed that the increase in the extrusion temperature also determined by the deformation and friction heat produces an increase in the thermal load particularly visible in the high deformed zone. This allows the obtaining of the semisolid condition for the material described by the temperature levels reported by the numerical simulations. Such technology results very useful for ribs deposition over flat surfaces.
Effect of ductile cast iron tool with grooved polishing and die coatings on friction behaviour in flat strip drawing of A7075-T6 alloy strip with quick heating
Authors: HARADA Sohdai
Published: August 2024

Abstract. A7075 aluminium alloy, a heat-treatable aluminium alloy, is expected to be applied to automobile frame parts from the viewpoint of high strength and light weight. To form this aluminium alloy, hot stamping using quick contact heating with a hot plate has been developed. To prevent seizure caused by hot stamping, the frictional properties of different tool coatings under warm and dry conditions were investigated by drawing tests of aluminium alloy strips using quick contact heating. Diamond like carbon (DLC) showed a low coefficient of friction and prevented seizure. The warm forming process allows the use of liquid lubricants. The frictional properties of cast iron and a simple surface texturing technique, grooved polishing, were investigated under warm and liquid lubrication conditions. The cast iron with grooved polishing showed the reduction in friction equivalent to DLC and prevented seizure as well.
Electroshock plastic constitutive modelling of high strength aluminum alloy based on GA-BP neural network
Authors: SONG Yanli
Published: August 2024

Abstract. Electrically-assisted forming is an effective way to improve the difficult-to-form materials. On basis of electro- and magneto- plastic effects, our team put forward a novel electroshock treatment (EST) process, which can not only improve the formability of the material but also improve the service performance of the formed parts. However, electrically-assisted forming involves nonlinear deformation with multi-physics coupling, the microstructural evolution and plastic mechanical response of materials under the coupling of electric current field and stress field are highly intricate, posing significant challenges in predicting macroscopic deformation behavior. The study of the characterization and precise control of plastic deformation's constitutive relation is therefore highly significant. In this work, the stress-strain curves of AA7075 under, different current densities, periods and power duration are obtained by means of the pulse electric current assisted tension test, and the intelligent prediction of the electroshock plastic constitutive relationship of AA7075 is realized based on the Genetic Algorithm (GA) optimized Back Propagation (BP) (GA-BP) neural network. The results show that the proposed algorithm can reduce the input parameters of the constitutive model to current, temperature and strain, and improve the computational efficiency. GA is used to optimize the initial weight and threshold of BP neural network, and the best hidden node number was selected as 12 by error verification to train the network. Compared with the traditional BP neural network, the neural network optimized by GA has higher accuracy, and in the plastic deformation stage, the coefficient of determination R2 between the predicted results and the experimental results is basically 99%, which is about 20% higher than that of the BP neural network. At the same time, it solves the data fluctuation in the long-term prediction due to the standard of satisfying the error in the prediction.
Research on circumferential tension-axial shear loading of thin-walled aluminum alloy tubes
Authors: ZHANG Shuning
Published: August 2024

Abstract. The deformation of parts with complex shapes is under a tensile and shear stress state. The deformation characteristics of materials under the tensile and shear stress state are beneficial for improving the prediction accuracy of the deformation of parts with complex shapes. A loading method of circumferential tension-axial shear of thin-walled tubes using two semi-circle mandrels and one specially designed tubular specimen is proposed in this paper. An experimental device was developed according to this method using servo electric cylinders. A thin-walled 5052 aluminum tube was tested and the strain path of the center point of the deformation zone was analyzed. This loading method can be used to investigate the characteristics of tubular material under the tensile and shear stress state.
Eccentricity-resistant process design and finite element analysis of deep hole cylindrical parts
Authors: LI Shuo
Published: August 2024

Abstract: In this paper, finite element analysis software was used to simulate and compare the deep-hole cylindrical parts formed by single process hot extrusion and double-process hot extrusion under the condition of uneven initial circumferential temperature of billet. The results show that the deformation resistance of the material is affected by the uneven temperature, and the strength of the single process hot extrusion parts is weakened because of the long punch length, which is easy to cause the eccentricity problem of the deep-hole cylindrical parts, and the wall thickness difference of the deep-hole cylindrical parts reaches 1.23 mm. The double-process hot extrusion can greatly reduce the influence of eccentricity on the deep hole cylindrical parts, make the wall thickness distribution more uniform, and the wall thickness difference is 0.38 mm. At the same time, the double-process hot extrusion reduces the forming force by 900 T and improves the feasibility of the process.
Suppression of non-uniform deformation using die shape in cylindrical deep drawing
Authors: MURAOKA Tsuyoshi
Published: August 2024

Abstract. This study presents a cylindrical deep drawing method that suppresses non-uniform deformation by die shape. In the cylindrical deep drawing, the material inflow in the circumferential direction varies due to the material anisotropy, resulting in unevenness at the edges of the cup, called the ear, after forming. Since the ears are usually trimmed after forming, there are concerns that the ear reduces yield rate and productivity due to the increased number of processes. The main approach study to the suppression of non-uniform deformation due to anisotropy has been the development of materials with suppressed material anisotropy. However, material development has been difficult to introduce because of the increased costs involved, and there has been a lack of development from the press process side. Therefore, this study clarified the effect of die shoulder radius on forming shapes in “Multiple R die” for cylindrical deep drawing by experiments and finite element analysis. Ear height can be suppressed if forming is performed in such a way that the effects of anisotropy and die shape cancel out each other by experimental and analysis results.
Numerical investigation of buckling behaviour of grid stiffened panel with opening during creep age forming
Authors: ZHOU Qingheng
Published: August 2024

Abstract. This study focuses on the prediction of the formability of the integrally stiffened panels with opening due to buckling during the loading stage and heating stage of the creep age forming (CAF) process. The simplified model of integrally stiffened panels with opening was established to investigate the buckling behavior of the stiffened panel subjected to pure bending moment at room temperature and ageing temperature. The influence of the main geometrical parameters (stiffener thickness and stiffener height) on the critical buckling stress and critical buckling strain of the stiffened panel at the two temperatures was studied by finite element simulation. With the increase of the stiffener thickness and the decrease of the stiffener height, the critical buckling stress will increase to about 570 MPa at room temperature and 475 MPa at ageing temperature, which makes the formability limit increase correspondingly. When the stiffened panel is in the elastic region, the non-dimensional critical buckling coefficient is reduced by 20%, compared with the traditional stiffened panel. When the stiffened panel enters the plastic region, the critical buckling strain increases and the forming limit enhances accordingly. The research results offer a significant reference for the structural optimization design of the stiffened panel, presenting a simplified approach for studying other special shapes of stiffened panels, which is helpful to ensure that the workpiece will not be buckled during the forming process.
Effect of feed pitch on formability in tube expansion using ball spin forming
Authors: OGURI Soma
Published: August 2024

Abstract. This study proposes a simple and localized forming method using a train of four balls in a tube-hoop direction that expands tube diameter at arbitrary axial positions. The balls travel in the tube direction while rotating around the tube axis. Compared with conventional methods, the expansion mechanism is compact as only one input-rotational drive forms taper and parallel sections. This paper particularly focuses on the effect of feed pitch for the parallel section forming and the ball gap to the cylinder on dimensional precision. An outer cylinder was used for securing the outer diameter as the inner surface of the cylinder can suppress the overshoot of the tube diameter. The experimental results verified the effect of the cylinder. When the ball gap to the cylinder was small enough to push the tube wall to the cylinder-inner surface, the tube diameter was stable at the target value regardless of the feed pitch for the parallel section forming. The tube thickness t decreased to 0.5 mm with increase of the clearance between the balls and the cylinder-inner surface just as designed. However, the thickness could not be less than 0.5 mm.
Example of the methodology for producing heterostructural systems using plastic deformation
Authors: PABICH Bartłomiej
Published: August 2024

Abstract. The study specifically examines the changes in the properties of the investigated systems as metal-to-metal composites and their constituent components. These heterostructural systems were crafted from microalloyed steel, reinforced with rheological non-uniformity due to the presence of Ti or Mg hcp phases. The influence of total deformation on the continuity of hcp layers and the degree of refinement of the matrix microstructure, i.e., microalloyed steel obtained through continuous recrystallization, was examined. The analysis delves into various strengthening mechanisms within the studied heterostructural systems, with particular emphasis on the strengthening effect resulting from the presence of low-plasticity hcp phases and their interaction with the entire system. The results of rheological studies conducted using channel compression tests and deep wire drawing (DWD) are presented. Microstructural studies have shown not only changes in the microstructure of the constituent materials but also the mutual interaction of these changes, directly affect the mechanical properties of the investigated heterogeneous materials.
Microstructure evolution of semi-solid billet fabricated by semi-solid isothermal heat treatment of wrought AlSi7Mg aluminum alloy
Authors: JIANG Jufu
Published: August 2024

Abstract: In this paper, the as-cast AlSi7Mg aluminum alloy billet was upsetted above recrystallization temperature to obtain wrought aluminum alloy with 50% deformation degree, and semi-solid isothermal treatment method was employed to achieve semi-solid billet of the wrought AlSi7Mg aluminum alloy. The microstructure observation and evolution law were investigated via optical microscope and scanning electron microscope. The results show that the primary α-Al phase can be changed from dendrite to spherical structure by semi-solid isothermal treatment of the wrought alloy (SSITWA). The complete transformation of the primary α-Al phase from dendrite to spherical structure can be achieved by increasing the isothermal temperature and prolongation of holding time. However, when the holding time is too long, the spheroidized grains will grow abnormally and eventually become irregularly shaped grains. High isothermal temperature can increase the primary α-Al size and reduce the time of dendrite to spheroidal grains. The average grain size of AlSi7Mg aluminum alloy semi-solid billet fabricated by SSITWA varies in a range of from 15 μm to 65 μm when the temperature and holding time change. The content of Al and Si elements in primary α-Al phase is obviously higher than that in liquid eutectic phase consisting of Al and Si elements, and the distribution of Mg element is uniform in the microstructure of semi-solid billet fabricated by SSITWA.