Article
Engineering, Mechanical
A. Kula, X. Jia, R. K. Mishra, M. Niewczas
Summary: The strain rate sensitivity (SRS) of binary Mg-Gd and Mg-Y alloys and the effect of solute on the rate-controlling mechanisms have been investigated. It was found that the steady-state SRS increases with solute concentration at low temperature, but exhibits reverse behavior at high temperature. The plastic flow properties are controlled by dislocation-solute interactions at the onset of plastic flow, while dislocation-dislocation interactions determine the work-hardening at higher flow stress.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Nanoscience & Nanotechnology
Feng Lu, Jonas K. Sunde, Calin D. Marioara, Randi Holmestad, Bjorn Holmedal
Summary: A modelling framework is presented for understanding the strength and work hardening contributions in age hardened Al-Mg-Si alloys. The model is based on TEM measurements of precipitate lengths and cross sections, as well as stress-strain curves obtained from tensile tests. The presence of precipitates strongly suppresses further work hardening beyond the uniform limit. New models are proposed to describe the work hardening at different aging conditions. The contribution from dislocation loops around non-sheared precipitates is taken into account, but an alternative mechanism suggesting that the precipitates act as obstacles for dislocation motion is also suggested.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Devarajan Nagarajan
Summary: The area fraction and number density of twins were measured in various magnesium alloys under different tensile strains. The results showed that twinning occurred rapidly in pure magnesium, gradually in magnesium-zinc alloys, and an intermediate behavior in magnesium-aluminum alloys. In the more dilute magnesium-aluminum alloys, the area fraction and number density decreased with concentration, but increased again for 9% aluminum, surpassing that of pure magnesium at high strains. In magnesium-zinc alloys, both parameters decreased monotonically with increasing zinc concentration up to the solubility limit. Additionally, the number density increased as the grain size decreased in all three materials. It was suggested that the availability of nucleating sites created by microplasticity and the increased specific grain boundary area contributed to the increased number density.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Dongdong Zhang, Hucheng Pan, Zhen Pan, Zhihao Zeng, Dongsheng Xie, Weineng Tang, Hongbo Xie, Rongguang Li, Gaowu Qin
Summary: Obtaining exceptionally high strength in large-scale Mg alloys using conventional free-forging process is a challenge. In this work, we achieved ultrahigh strength in coarse-grained Mg-13Gd forged alloys by maximizing precipitation hardening effect. High-temperature forging promotes the formation of strong basal texture and enables supersaturated Gd atoms, leading to a surprising increment in yield strength. We propose a new strategy for fabricating high-strength forged Mg alloys via texture hardening and precipitation hardening.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Chemistry, Physical
Wojciech Jurczak, Tomasz Trzepiecinski, Andrzej Kubit, Wojciech Bochnowski
Summary: The aim of this study is to investigate the influence of magnesium content and strain rate on the grain refinement and mechanical properties of Al-Mg alloys. The results showed that increasing the magnesium content strengthened the alloys and caused a change in the fracture surface orientation. Additionally, an increase in strain rate led to an increase in dynamic strength compared to static strength.
Article
Chemistry, Physical
Lu Zhao, Hongge Yan, Jihua Chen, Weijun Xia, Bin Su, Min Song, Zhenzhen Li, Xinyu Li, Yang Liao
Summary: The study demonstrates the importance of high ductility and moderate strength in Al-Mg alloys, which can be achieved through strong work-hardening abilities. Factors such as low density of pre-existing dislocations, random grain orientations, and reduced stacking fault energy contribute to the enhancement of work-hardening capacity and desirable ductility, while unevenly distributed precipitates are harmful for work-hardening and lead to reduced ductility.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
S. Sivasankaran, K. R. Ramkumar, Hany R. Ammar, Fahad A. Al-Mufadi, Abdulaziz S. Alaboodi, Osama Mohamed Irfan
Summary: The main goals of this work were to manufacture novel Al-Zn extruded alloys with varying Zn content, and to investigate microstructural evolutions, hot deformation, and work hardening behavior at different temperatures. Al-20Zn alloy exhibited improved mechanical performance compared to other alloys, with stress decreasing with increasing temperature and increasing with higher Zn content.
METALS AND MATERIALS INTERNATIONAL
(2022)
Article
Materials Science, Multidisciplinary
Behzad Sadeghi, Pasquale Cavaliere
Summary: The study evaluated Al-Mg alloy structure reinforced with carbon nanotubes, produced through modified flake metallurgy technique and hot extrusion, which exhibited a bimodal microstructure contributing to high strength, uniform elongation, and strain hardening ability. The presence of Mg transformed the native Al2O3 layer into spinel MgAl2O4 nano-phases, improving the interfacial bonding of Al-Al and Al-CNT. The effect of reinforcing phases percentages on dislocations mechanisms evolution was assessed through stress relaxation tests.
Article
Materials Science, Multidisciplinary
S. Medrano, H. Zhao, B. Gault, F. De Geuser, C. W. Sinclair
Summary: The softening and strengthening effects in pre-deformed and aged Al-Mg-Cu alloys were evaluated using microscopy, mechanical testing and modeling. A refined model for work hardening response was found to accurately determine the precipitation hardening contribution. The mechanical response of these alloys was not significantly affected by Cu content, pre-deformation level or aging temperature, indicating robustness in terms of composition variations.
Article
Engineering, Mechanical
Dengshan Zhou, Xiuzhen Zhang, Hao Wang, Yue Li, Binhan Sun, Deliang Zhang
Summary: This study investigates the influence of Mg content and dynamic strain aging (DSA) on the tensile flow behavior of Al-Mg alloys. The results show that the synergistic effect of Mg-dislocation interactions and DSA improves the strain hardening capacity of Al-Mg alloys.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Materials Science, Multidisciplinary
Qinxiang Xia, Shuai Yuan, Gangfeng Xiao, Jinchuan Long, Xiuquan Cheng
Summary: Through meso-simulation using 3D-CPFEM, it was found that the improved Voce hardening law and initial texture characteristics can predict well the mechanical response and texture evolution of ZK61 magnesium alloy during hot compression under different temperatures and strain rates. The transformation of basal plane texture of ZK61 tubular blank into basal fiber texture after hot compression is attributed to orientation deflection of grains with larger basal slip systems Schmid factor (SF) and orientation retention of grains with c-axis parallel to axial direction (AD) of tubular blank. The change of grain orientation corresponding to basal plane texture component of the tubular blank has minimal contribution to the formed basal fiber texture.
MATERIALS TODAY COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
M. Avateffazeli, S. I. Shakil, A. Hadadzadeh, B. Shalchi-Amirkhiz, H. Pirgazi, M. Mohammadi, M. Haghshenas
Summary: In this paper, the correlation between microstructure and mechanical properties, including work hardening rates, of two aluminum alloys (A205 and AlSi10Mg) manufactured using the laser powder-bed fusion technique was investigated. Tensile tests were performed on both materials in as-built and heat-treated conditions, and microstructural characterizations were conducted to identify the microstructure-property correlations. The results showed that the A205 alloy exhibited uniform equiaxed grain structure, while the AlSi10Mg alloy had a cellular microstructure. The mechanical properties and work-hardening behavior of the two alloys were influenced by their distinct microstructural features and their evolution upon aging.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Crystallography
Mahdieh Shahmardani, Napat Vajragupta, Alexander Hartmaier
Summary: The effective mechanical properties of polycrystals are influenced by single-crystal properties and crystallographic orientation, as well as by crystal plasticity parameters. This study systematically investigates the effect of changes in crystal plasticity parameters on polycrystals' mechanical behavior, filling a gap in understanding the relationship between these parameters. Using a numerical model with 100 grains and a non-local crystal plasticity model, the study provides insights into the correlation between microscopic crystal descriptions and macroscopic polycrystal behavior.
Article
Chemistry, Physical
Yifan Bu, Xiuzhen Zhang, Dengshan Zhou
Summary: Experimental observations show that the strain dependence of the Hall-Petch slope in Al-Mg alloys is significantly influenced by the formation of Laders bands and the Mg content. The Hall-Petch slope initially drops due to Laders deformation, then increases with plastic strain until reaching its maximum, and subsequently decreases due to dynamic recovery. Alloys with higher Mg contents exhibit a larger Hall-Petch slope at a given strain, and their dynamic recovery is postponed until a larger strain is reached. Interestingly, a model developed for low stacking fault energy materials accurately describes the relationship between the Hall-Petch slope, Mg content, and strain magnitude.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Chunquan Liu, Xianhua Chen, Yaobo Hu, Wei Zhang, Yusheng Zhang, Jianbo Li, Fusheng Pan
Summary: This study prepares a gradient ultrafine-grained structure on the surface of a magnesium alloy using sliding friction treatment. The new material exhibits significantly improved yield strength and excellent ductility compared to homogeneous structures. Transmission electron microscopy and electron backscatter diffraction analyses reveal that the refined grain structure and grain orientation modification contribute to the enhanced plastic deformation ability.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)