Review
Metallurgy & Metallurgical Engineering
M. Rakshith, P. Seenuvasaperumal
Summary: Despite the high specific strength and low density of magnesium (Mg) alloys, their hexagonal close-packed crystal structure lacks active slip systems at room temperature, leading to poor ductility and formability. Research on AZ and ZK series alloys shows that they exhibit better room temperature strength and flow characteristics through solute elements. Commercial viability of these alloys relies on grain refinement and elimination of casting defects through metal processing techniques.
JOURNAL OF MAGNESIUM AND ALLOYS
(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
Metallurgy & Metallurgical Engineering
Yu-Ying He, Sheng-Wen Bai, Gang Fang
Summary: In this study, the dynamic recrystallization (DRX) behavior of a Mg-Al-Zn-RE alloy with abundant second-phase particles during hot extrusion is investigated using a combination of finite element (FE) and cellular automaton (CA) models. The results show that the extrusion conditions have a significant influence on the microstructural evolution of the magnesium alloy.
JOURNAL OF MAGNESIUM AND ALLOYS
(2022)
Article
Materials Science, Multidisciplinary
Lianyang Chen, Tian Ye, Yongshuai Wang, Ding Zhou, Tao Suo, Qiong Deng, Feng Zhao, Qingyuan Wang
Summary: The study found that pre-twinning can effectively enhance the strength and ductility of magnesium alloy, while high twin density can improve its mechanical properties through twin-dislocation interaction. It was also concluded that high strain rate in cold dynamic extrusion is an effective method for preparing pre-twinning magnesium alloy with good mechanical properties.
MATERIALS CHARACTERIZATION
(2021)
Article
Nanoscience & Nanotechnology
Abhinav Srivastava, Matthew W. Vaughan, Bilal Mansoor, Wahaz Nasim, Robert E. Barber, Ibrahim Karaman, Karl T. Hartwig
Summary: This study demonstrates the effectiveness of tube equal channel angular extrusion (tECAE) in enhancing mechanical properties through grain refinement and texture control in Mg alloy tubes. The refined grains and increased strength levels achieved after tECAE processing show the potential for improving mechanical properties in other tubular materials as well.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Engineering, Civil
Marek Tkocz, Karolina Kowalczyk, Tomasz Bulzak, Magdalena B. Jablonska, Marek Hawryluk
Summary: The material deformation behavior during the DRECE process has been analyzed using FEM simulations. The simulations considered two different channel angles and two processing routes. The results showed significant strain and stress inhomogeneities across the strip thickness, which can be mitigated by choosing a specific processing route. The smaller channel die angle generates larger strain and higher strength of the strip, but reduces its ductility.
ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING
(2023)
Article
Chemistry, Physical
Anna Dobkowska, Aleksandra Zielinska, Irena Paulin, Crtomir Donik, Maciej Lojkowski, Milena Koralnik, Boguslawa Adamczyk-Cieslak, Krystian Paradowski, Marek Tkocz, Dariusz Kuc, Jiri Kubasek, Matjaz Godec, Wojciech Swieszkowski
Summary: We investigated the microstructure, mechanical, and corrosion properties of an AZ61 alloy extruded using the KoBo method. The KoBo method enables extrusion of AZ61 without preheating and results in significant microstructure refinement. However, this study found that it did not enhance the strength or corrosion resistance of the AZ61 alloy. The continuously precipitated Mg17Al12 phase along the grain boundaries was identified as the main factor affecting the alloy's properties.
JOURNAL OF ALLOYS AND COMPOUNDS
(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
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
Nanoscience & Nanotechnology
M. Sabbaghian, R. Mahmudi, K. S. Shin
Summary: The influence of equal channel angular pressing (ECAP) and simple shear extrusion (SSE) on the microstructure, texture development, and mechanical properties of Mg-4Zn alloy was investigated. It was found that SSE resulted in smaller grain sizes and a different texture development compared to ECAP. Both ECAP and SSE improved the strength of the alloy, but SSE showed better results.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Engineering, Mechanical
Tsuyoshi Mayama, Sean R. Agnew, Koji Hagihara, Kentaro Kamura, Kazuma Shiraishi, Michiaki Yamasaki, Yoshihito Kawamura
Summary: The influence of alpha-Mg/LPSO phase interfaces on the flow stress of as-cast Mg-Zn-Y alloys was experimentally and numerically evaluated. The results showed that the flow stresses of Mg-Zn-Y alloys with LPSO phase fractions ranging from 40 to 85% were higher than those of single phase alpha-Mg or LPSO alloys. Comparison between Mg-Zn-Y alloys and Mg-Zn-Y-Zr alloys revealed that the flow stresses of Mg-Zn-Y alloys with LPSO phase fractions of 25 and 40% were insensitive to grain size, while the flow stress of alpha-Mg single-phase alloy showed clear grain size dependence. Crystal plasticity analysis successfully reproduced the observed stress-strain behavior, indicating that alpha-Mg/LPSO phase interfaces are effective obstacles against dislocation slip in two-phase Mg alloys containing LPSO phase.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Materials Science, Multidisciplinary
Bo Che, Liwei Lu, Wei Kang, Yinhua Zhong, Min Ma, Longfei Liu, Zhiqiang Wu
Summary: A new process called expansion-shear extrusion (ESE) has been proposed for producing AZ31 Mg alloy sheets. The effect of expansion sphere diameter on the deformation behavior of the alloy was analyzed using the finite element method and electron backscatter diffraction. The results showed that increasing the diameter of the expansion ball led to an increase in the dead zone range. At a diameter of 30 mm, the parameters for strain inhomogeneity and flow velocity non-uniformity were low. Moreover, the ESE deformation process resulted in a refinement of the average grain size of the alloy.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2022)
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
Nanoscience & Nanotechnology
S. Picak, H. C. Yilmaz, I Karaman
Summary: High temperature equal channel angular pressing (ECAP) was used to activate simultaneous twinning-induced (TWIP) and transformation-induced plasticity (TRIP) in the CoCrFeMnNi high entropy alloy (HEA), resulting in a high strength level and uniform plastic deformation ability. This phenomenon was attributed to the high strength levels applied via ECAP and the relatively low stacking fault energy of the present HEA.
SCRIPTA MATERIALIA
(2021)
Article
Chemistry, Physical
Feng Zhao, Jinhong Xie, Yikun Zhu, Qiancheng Liu, Tian Ye, Lianyang Chen, Tao Suo, Kaixuan Wang, Tao Wang, Qingyuan Wang
Summary: Dynamic extrusion is a promising method to improve both strength and ductility in magnesium alloys by introducing high-density extension twins and dislocation structures. Annealing after dynamic extrusion enhances strain hardening and strength, with high-density twins promoting more dislocation nucleation and offering additional slip systems for improved ductility. This study suggests that increasing twin density through dynamic extrusion can enhance the mechanical properties of magnesium alloys efficiently.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
