Article
Materials Science, Multidisciplinary
Mehran Nouri, Hamidreza Mohammadian Semnani, Esmaeil Emadoddin
Summary: The study showed that adding a direct extrusion channel during twist extrusion process can increase hardness distribution and achieve a more homogenous structure.
METALS AND MATERIALS INTERNATIONAL
(2021)
Article
Engineering, Mechanical
Reeju Pokharel, Bjorn Clausen, Daniel J. Savage, Jianzhong Zhang, Sven C. Vogel, Roberta Beal, James Valdez, Veronica Anghel, Donald W. Brown, George T. Gray III
Summary: Uniaxial compression tests were conducted on 99.9% pure polycrystalline ������-tin (Sn) at different strain rates and temperatures. The results showed that the strain rate and temperature have significant effects on the stress-strain response, microstructure evolution, and stress relaxation behavior. Neutron diffraction and electron backscatter diffraction were used to characterize the crystallographic structures and deformation mechanisms. Elastic-plastic self-consistent simulations were performed to understand the macroscopic behavior.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Materials Science, Multidisciplinary
Hamid Bohluli, Mohammad Lakhi, Masoud Rakhshkhorshid
Summary: This research investigates the effect of per pass applied strain on the mechanical and electrical properties of commercial pure copper in twist extrusion process. Two dies with twist angles of 37 degrees and 56 degrees were used to perform the process in 8 passes. Finite element simulation was used to determine the average per pass applied strain. Compressive and hardness testing were conducted to assess mechanical properties, while optical and SEM images were used to analyze the grain refinement and mechanical properties.
METALS AND MATERIALS INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
H. Ataei, M. Shahbaz, H. S. Kim, N. Pardis
Summary: The study combined conventional extrusion and twist extrusion to propose a new design called Rectangular Vortex Extrusion (RVE) for single-pass severe plastic deformation. It was found that increasing the die twist angle and friction condition had a synergistic effect on increasing the accumulated strain values in the deformation process.
METALS AND MATERIALS INTERNATIONAL
(2021)
Article
Nanoscience & Nanotechnology
Nadja Berndt, Philipp Frint, Marcus Boehme, Soren Mueller, Martin F. -X. Wagner
Summary: Cold extrusion of AA1080 aluminum alloy results in a pronounced multi-gradient deformation structure with distinct differences in terms of texture, grain size, and strain hardening.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Seyed Elias Mousavi, Ali Sonboli, Mahmood Meratian, Mohabbat Amirnejad, Seyed Hadi Mohamadi Azghandi, Paul Munroe
Summary: The study shows that low stacking fault energy alloys processed by ECAP can achieve unexpected mechanical properties, with high ductility reaching up to -80% while maintaining good tensile strength. The investigation of alloy microstructure reveals a combination of deformation mechanisms, including slip and twinning, accompanied by grain boundary serration and grain fragmentation. These deformation modes trigger the unexpected mechanical properties in this alloy.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
S. Muralidharan, U. Mohammed Iqbal
Summary: This article proposes a new severe plastic technique called Multi-angular twist channel extrusion (MATE) for processing AA2024 aluminium alloy. The MATE method can impose a large strain in a single pass with better strain homogeneity and lower punch load. The study shows that an average effective strain of 2.78 was achieved with good strain homogeneity, and the tensile strength and hardness of the alloy were significantly increased. The MATE process also led to grain refinement, strain hardening, the development of a strong texture, and a high dislocation density in the extruded metal.
METALS AND MATERIALS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Xin Che, Beibei Dong, Qiang Wang, Kai Liu, Mu Meng, Zhi Gao, Jin Ma, Fulai Yang, Zhiming Zhang
Summary: The RBE process shows potential in producing high-quality cup-shaped AZ80 magnesium alloy pieces through controlling grain size and dynamic recrystallization fraction by adjusting rotating revolutions and processing temperature. The refined microstructure and weakened texture in RBE samples contribute to improved quality and performance of the cup-shaped samples.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Engineering, Manufacturing
H. Bohluli, K. Khalili, S. M. H. Seyedkashi
Summary: The research shows that the consecutive process of multiple twist extrusion and forward extrusion significantly improves the mechanical properties of aluminum-copper bimetallic bars, including compressive yield strength and shear bond strength, while also increasing hardness. Twist extrusion reduces grain size, and mechanical locking is the main factor in bond formation.
CIRP JOURNAL OF MANUFACTURING SCIENCE AND TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Guowei Zhou, Ruxue Liu, Weiqin Tang, Dayong Li, Yinghong Peng, Peidong Wu
Summary: Research on the evolutions of strain-rate sensitivity in two slip modes, basal and prismatic in AZ31B alloy sheet, reveals that at high temperatures, the alloy becomes more sensitive to strain rate under rolling direction tension and the anisotropy also presents a clearly increasing trend with loading rate. Numerical simulation results suggest that the difference in SRSs is responsible for the strain-rate dependence of the r-value at high temperatures, which may present different evolution trends with temperature.
Article
Materials Science, Multidisciplinary
N. M. Krywopusk, L. J. Kecskes, T. P. Weihs
Summary: Processing of 99.9% pure, as-cast magnesium by Equal Channel Angular Extrusion significantly reduces grain size to around 30 μm after the second pass, but grain size varies after the third and fourth passes depending on extrusion rate. Slower rates lead to an increase in grain size after the third and fourth passes, while the fastest rate maintains relatively consistent grain size. The presence of twins in microstructures also varies with extrusion rate.
MATERIALS CHARACTERIZATION
(2021)
Article
Automation & Control Systems
Nanyang Zhu, Chaoyang Sun, Lingyun Qian, Mingjia Wang, Xintong Li
Summary: This study proposes a new variable circular channel angular extrusion (VCCAE) process for manufacturing magnesium alloy plates with rib-web structure. The feasibility and accuracy of the process are validated through numerical simulations and experiments. The results show that stress and strain distribution in the longitudinal section is highly inhomogeneous, with significant stress concentration at the shear plane. The microstructure in the angular region is more uniform and finer, indicating that severe shear deformation induced by the angular channel promotes deformation uniformity and grain refinement.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
M. Haghpanah, A. Esmaeilnia, M. R. Sabour, E. Taherkhani, M. Mosavi Mashhadi, G. Faraji
Summary: In this study, hydrostatic twist extrusion (HTE) was used to process long ultrafine grained (UFG) bulk samples. The use of high-pressure fluid eliminated surface contact between die and sample. The HTE process resulted in a reduction in grain size and an improvement in mechanical properties of the aluminum samples. The process shows promise for future industrial applications.
Article
Materials Science, Multidisciplinary
Franziska Staab, Enrico Bruder, Lukas Scha, Konstantin Skokov, David Koch, Benjamin Zingsem, Esmaeil Adabifiroozjaei, Leopoldo Molina-Luna, Oliver Gutfleisch, Karsten Durst
Summary: Textured nanocrystalline SmCo5-Cu magnets are produced by high-pressure torsion (HPT) of powder blends consisting of SmCo5 and Cu powder. The process overcomes limitations imposed by the phase diagram as in conventional sintering routes, enabling a free selection of the magnetic phase and the grain boundary phase. Increasing number of rotations during HPT leads to structural refinement, increasing coercivity, and amorphous structure of strongly deformed SmCo5 particles. The magnetic hardening is attributed to microstructural refinement and magnetic decoupling of hard magnetic SmCo5 grains by Cu.
Article
Materials Science, Multidisciplinary
Seyed Moien Faregh, Ghader Faraji, Mahmoud Mosavi Mashhadi, Mohammad Eftekhari
Summary: The study found that the UFG pure copper tube processed by HTCEE method exhibited significant mechanical anisotropy, which can be reduced by the HTCEE process while maintaining low ductility loss.
INTERNATIONAL JOURNAL OF MINERALS METALLURGY AND MATERIALS
(2022)
Article
Engineering, Manufacturing
Lavinia Tonelli, Mohamed M. Z. Ahmed, Lorella Ceschini
Summary: This study focuses on the heat treatment and wear resistance of LPBF Co28Cr6Mo alloy. The optimized heat treatment conditions have positive effects on hardness and frictional wear behavior of the alloy.
PROGRESS IN ADDITIVE MANUFACTURING
(2023)
Article
Materials Science, Multidisciplinary
Akbar Heidarzadeh, Rasoul Khajeh, Reza Jabraeili, Hamid Reza Jafarian, Mohamed Ahmed, Nokeun Park, Unhae Lee
Summary: The main problem in post-treatment of laser powder bed fusion (L-PBF) AlSi10Mg is the strength-ductility trade-off. Friction stir welding (FSW) was used to join AlSi10Mg plate produced by L-PBF and overcome this trade-off. FSW resulted in improved microstructure, texture, and mechanical properties. Tensile elongation was enhanced by 173% with a negligible decrease in strength (9%). The joint fractured from the stir zone during tensile loading, forming a bimodal dimple structure.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Materials Science, Multidisciplinary
Akbar Heidarzadeh, Roghayeh Mohammadzadeh, Mohamed Ahmed, Yutao Pei
Summary: Friction stir processing (FSP) has been used to process Monel alloy, resulting in refined grain structure and improved mechanical properties. The stir zone (SZ) exhibits significantly refined grains with a high fraction of high-angle grain boundaries (HAGBs), leading to increased yield strength and ultimate tensile strength.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Chemistry, Analytical
Hany Hassanin, Mahmoud Ahmed El-Sayed, Mahmoud Ahmadein, Naser A. Alsaleh, Sabbah Ataya, Mohamed M. Z. Ahmed, Khamis Essa
Summary: This study uses statistical techniques to investigate and optimize the process parameters of Laser Powder Bed Fusion (LPBF) for making Ti6Al4V components with improved density and surface finish. The optimization results demonstrate the practicality of optimizing Ti6Al4V and other metal materials and expanding the potential of LPBF for a wide range of applications.
Article
Materials Science, Multidisciplinary
Kamel Touileb, Elawady Attia, Rachid Djoudjou, Abdallah Benselama, Albaijan Ibrahim, Sahbi Boubaker, Jose Ponnore, Mohamed M. Z. Ahmed
Summary: A study was conducted to investigate the effect of laser welding parameters on bead profile and microchemistry compositions differences of two thin AISI 316 industrial stainless steel casts with different sulfur contents. The study involved 27 tests with different welding speeds, shield gases, and focal lengths, and response surface methodology was used to analyze the depth, aspect ratio, and bead cross section profile. Linear and quadratic polynomial models were developed to predict the weld bead geometry, and optical microscopy was used to analyze the welded area. The results showed that the main factors influencing the weld depth were the focus point and power input energy, and sulfur played a significant role in determining the shape of the laser weld bead.
Article
Chemistry, Multidisciplinary
Yousef G. Y. Elshaghoul, Mohamed M. El-Sayed Seleman, Ashraf Bakkar, Sarah A. Elnekhaily, Ibrahim Albaijan, Mohamed M. Z. Ahmed, Abdou Abdel-Samad, Reham Reda
Summary: This study aimed to explore the feasibility of using friction stir deposition (FSD) technique to build multilayered parts of one aluminum alloy on a substrate of another aluminum alloy, and to optimize the deposition process parameters. The results showed that defect-free continuously multilayered parts could be produced by achieving the appropriate deposition conditions, and the deposited materials exhibited refined grain structure and uniformly distributed fragment precipitates.
APPLIED SCIENCES-BASEL
(2023)
Article
Crystallography
Kamel Touileb, Elawady Attia, Rachid Djoudjou, Abdejlil Chihaoui Hedhibi, Abdallah Benselama, Albaijan Ibrahim, Mohamed M. Z. Ahmed
Summary: This study investigates the effects of sulfur on weld bead morphology in the laser process. It is found that the focus point position has a significant influence on the depth of the weld for high sulfur alloy, while the interaction between shield gas and focus point plays an important role in low sulfur alloy. The experimental results also demonstrate the surface-active role of sulfur in partially penetrated welds.
Article
Construction & Building Technology
Ahmadreza Khodayari, Danial Fakhri, Adil Hussein Mohammed, Ibrahim Albaijan, Arsalan Mahmoodzadeh, Hawkar Hashim Ibrahim, Ahmed Babeker Elhag, Shima Rashidi
Summary: The objective of this research is to introduce and refine an equation based on the gene expression programming (GEP) method to calculate the fracture toughness of reinforced concrete, minimizing the need for costly and time-consuming laboratory experiments. Various types of reinforced concrete were tested using the central straight notched Brazilian disc (CSNBD) test to determine the effective fracture toughness (Keff). Six key input factors influencing the Keff, including sample type, diameter, thickness, length, force, and loading angle, were considered. The GEP model was optimized based on training datasets and showed exceptional proficiency in predicting the Keff of concrete.
STEEL AND COMPOSITE STRUCTURES
(2023)
Article
Economics
Mohamed Mohieldin Abdelrhman Ahmed, Wajid Ali
Summary: The changes in military expenditure of Sudan are influenced by the country's economic growth. This asymmetric relationship cannot be tested using linear time series models. The study uses two-state Markov regime-switching models to investigate the impact of military spending on economic growth in Sudan from 1961 to 2019. Two key findings emerge: the relationship between military spending and economic growth depends on the state, and in a low-growth regime, an increase in military spending is detrimental to economic growth.
GLOBAL & LOCAL ECONOMIC REVIEW
(2023)
Article
Construction & Building Technology
Qiuyang Cheng, H. Elhosiny Ali, Ibrahim Albaijan
Summary: The research aims to characterize the behavior of nonlocal nanocyndrical beams with uniform and nonuniform cross sections by combining vibrational analysis with stability analysis. Three distinct section functions are used to determine the nonuniformity of the beams. Eringen's nonlocal theory is combined with the Timoshenko beam model for different boundary conditions, and the extended differential quadrature technique is used to solve the governing equations. The findings reveal that the nonlocal impact has the opposite effect on the frequency of the uniform cantilever nanobeam, offering a cost-effective benefit of improving the frequency and buckling stress of a resonator without requiring additional material.
ADVANCES IN CONCRETE CONSTRUCTION
(2023)
Article
Engineering, Multidisciplinary
Abdulrahman I. Alateyah, Mohammed Nejlaoui, Mohammed Albadrani, Abdulrahman Alrumayh, Hassan Abd El-Hafez, Hisham A. Alrumayh, Sufyan A. Alomari, Abdulaziz H. Alomayrini, Hamad H. Albazie, Waleed H. El-Garaihy
Summary: This study proposes a new gait-inspired method based on a genetic algorithm (GA) for synthesizing a four-bar mechanism for exoskeletons. The trajectory for each phase of the gait is calculated and merged using optimization algorithms. It is found that the GA outperforms other literature techniques. Finally, a solid model of the proposed design for a lower limb exoskeleton is depicted, and a stick diagram is used to illustrate the simulation of the planned linkage for one gait cycle.
Review
Chemistry, Multidisciplinary
Ashraf Bakkar, Mohamed M. El-Sayed Seleman, Mohamed M. Zaky Ahmed, Saeed Harb, Sami Goren, Eskander Howsawi
Summary: Heavy oil fly ash (HOFA) is a hazardous waste generated in power stations using heavy oil as fuel, containing significant amounts of valuable vanadium (V) and nickel (Ni). This paper critically reviews different approaches for the recovery of V and Ni from HOFA, including leaching, chemical precipitation, solvent extraction, and ion exchange. The optimal operational parameters and effects on recovery efficiency are discussed, along with the use of strong mineral acids for dissolving all metals in HOFA. The promising environmentally friendly approach of bioleaching using appropriate bacteria and fungi is also highlighted.
Article
Nanoscience & Nanotechnology
Abdulrahman I. Alateyah, Mahmoud El-Shenawy, Ahmed Nassef, Medhat El-Hadek, Mohamed M. Z. Ahmed, Hanan Kouta, Samar El Sanabary, Waleed H. El-Garaihy
Summary: The aim of this study was to investigate the effect of ECAP processing parameters, such as number of passes, ECAP die angle, route type, and processing temperature, on the mechanical and electrical properties of pure copper. Finite element method and response surface methodology were used to analyze the distribution of stress and plastic strain during ECAP processing and identify the optimum ECAP conditions. A genetic algorithm was applied to further optimize the ECAP conditions. The developed models were validated and compared with experimental findings to demonstrate their reliability as predictive tools. The optimization results indicated that route Bc was more effective in improving certain mechanical properties, while route A was more effective in improving the electrical conductivity of the Cu billets. The optimum die angle, number of passes, and processing temperature for the desired properties were also identified.
REVIEWS ON ADVANCED MATERIALS SCIENCE
(2023)
Article
Chemistry, Physical
Ali Abd El-Aty, Cheng Cheng, Yong Xu, Yong Hou, Jie Tao, Shenghan Hu, Bandar Alzahrani, Alamry Ali, Mohamed M. Z. Ahmed, Xunzhong Guo
Summary: In this study, the U-R relationship curve of the Al alloy tube was fitted and a mathematical model for the U-R relationship was proposed based on the forming results. The modified U-R mathematical formula was applied in both simulation and actual bending experiments, and showed good agreement with the FE modeling results.
