In the past two years, significant progresses have been achieved in high-performance cast and wrought magnesium and magnesium alloys, magnesium-based composites, advanced cast technologies, advanced ...processing technologies, and functional magnesium materials, such as Mg ion batteries, hydrogen storage Mg materials, bio-magnesium alloys, etc. Great contributions to the development of new magnesium alloys and their processing technologies have been made by Chongqing University, Shanghai Jiaotong University, Chinese Academy of Sciences, Helmholtz Zentrum Geesthacht, Queensland University, Brunel University, etc. This review paper is aimed to summarize the latest important advances in cast magnesium alloys, wrought magnesium alloys and functional magnesium materials worldwide in 2018–2019, including both the development of new materials and the innovation of their processing technologies. Based on the issues and challenges identified here, some future research directions are suggested, including further development of high-performance magnesium alloys having high strength and superior plasticity together with high corrosion resistance and low cost, and fundamental research on the phase diagram, diffusion, precipitation, etc., as well as the development of advanced welding and joining technology.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Research on magnesium alloys continues to attract great attention, with more than 3000 papers on magnesium and magnesium alloys published and indexed in SCI in 2020 alone. The results of bibliometric ...analyses show that microstructure control and mechanical properties of Mg alloys are continuously the main research focus, and the corrosion and protection of Mg alloys are still widely concerned. The emerging research hot spots are mainly on functional magnesium materials, such as Mg ion batteries, hydrogen storage Mg materials, and bio-magnesium alloys. Great contributions to the research and development of magnesium alloys in 2020 have been made by Chongqing University, Chinese Academy of Sciences, Central South University, Shanghai Jiaotong University, Northeastern University, Helmholtz Zentrum Geesthacht, etc. The directions for future research are suggested, including: 1) the synergistic control of microstructures to achieve high-performance magnesium alloys with concurrent high strength and superior plasticity along with high corrosion resistance and low cost; 2) further development of functional magnesium materials such as Mg batteries, hydrogen storage Mg materials, structural-functional materials and bio-magnesium materials; 3) studies on the effective corrosion protection and control of degradation rate of magnesium alloys; 4) further improvement of advanced processing technology on Mg alloys.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
More than 4000 papers in the field of Mg and Mg alloys were published and indexed in Web of Science (WoS) Core Collection database in 2021. The bibliometric analyses indicate that the microstructure, ...mechanical properties, and corrosion of Mg alloys still are the main research focus. Mg ion batteries and hydrogen storage Mg materials have attracted much attention. Significant contributions to the research and development of magnesium alloys were made by Chongqing University, Shanghai Jiaotong University, and Chinese Academy of Sciences in China, Helmholtz Zentrum Hereon in Germany, Ohio State University in the United States, the University of Queensland in Australia, Kumanto University in Japan, and Seoul National University in Korea, University of Tehran in Iran, etc.. This review is aimed to summarize the progress in the development of structural and functional Mg and Mg alloys in 2021. Based on the issues and challenges identified here, some future research directions are suggested.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
While research on lightweight materials has been carried out for decades, it has become intensified with recent climate action initiatives leading pathways to net zero. Aluminum alloys are at the ...pinnacle of the light metal world, especially in the automotive and aerospace industries. This review intends to highlight recent developments in the processing, structure, and mechanical properties of structural Al-Si alloys to solve various pressing environmental issues via lightweighting strategies. With the excellent castability of Al-Si alloys, advancements in emerging casting methods and additive manufacturing processes have been summarized in relation to varying chemical compositions. Improvements in thermal stability and electrical conductivity, along with superior mechanical strength and fatigue resistance, are analyzed for advanced Al-Si alloys with the addition of other alloying elements. The role of Si morphology modification, along with particle distribution, size, and precipitation sequencing, is discussed in connection with the improvement of static and dynamic mechanical properties of the alloys. The physics-based damage mechanisms of fatigue failure under high-cycle and low-cycle fatigue loading are further elaborated for Al-Si alloys. The defect, porosity, and surface topography related to manufacturing processes and chemical compositions are also reviewed. Based on the gaps identified here, future research directions are suggested, including the usage of computational modeling of microstructures and the integration of artificial intelligence to produce mass-efficient and cost-effective solutions for the manufacturing of Al-Si alloys.
•This review paper is aimed to summarize the latest important advances in cast magnesium alloys, wrought magnesium alloys, bio-magnesium alloys, Mg-based energy storage materials and corrosion and ...protection of Mg alloy in 2022, including both the development of new materials and the innovation of their processing technologies.•The main research focus of magnesium alloys were analyzed by bibliometrics. The bibliometric analyses indicate that the microstructure, mechanical properties, and corrosion of Mg alloys are still the main research focus. Bio-Mg materials, Mg ion batteries and hydrogen storage Mg materials have attracted much attention.•Based on the issues and challenges identified here, some future research directions are suggested.
More than 4600 papers in the field of Mg and Mg alloys were published and indexed in the Web of Science (WoS) Core Collection database in 2022. The bibliometric analyses indicate that the microstructure, mechanical properties, and corrosion of Mg alloys are still the main research focus. Bio-Mg materials, Mg ion batteries and hydrogen storage Mg materials have attracted much attention. Notable contributions to the research and development of magnesium alloys were made by Chongqing University (>200 papers), Chinese Academy of Sciences, Shanghai Jiao Tong University, and Northeastern University (>100 papers) in China, Helmholtz Zentrum Hereon in Germany, Ohio State University in the USA, the University of Queensland in Australia, Kumanto University in Japan, and Seoul National University in Korea, University of Tehran in Iran, and National University of Singapore in Singapore, etc. This review is aimed to summarize the progress in the development of structural and functional Mg and Mg alloys in 2022. Based on the issues and challenges identified here, some future research directions are suggested.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Magnesium (Mg) alloys, as one of the lightest structural metallic materials, have attracted considerable attention in the automotive, aerospace, and microelectronic industries. However, wrought Mg ...alloys are easy to form a strong basal texture with the basal planes of hexagonal close-packed unit cells being parallel to the processing direction during hot processing. This extremely deteriorates the stretch formability of Mg alloy sheets at room temperature (RT) and limits their widespread industrial applications. To overcome this drawback, many studies have been devoted to controlling microstructures including grain sizes, texture characteristics and precipitates to achieve high-performance Mg alloy sheets via alloying and new processing techniques. In this review, we briefly summarize recent advances in enhancing the stretch formability of Mg alloy sheets at RT from two major aspects: (1) by the design of new alloy systems and (2) by the exploitation of advanced processing techniques. Both strategies hold great promise for developing high-performance and low-cost Mg alloy sheets with a superior combination of strength, ductility and stretch formability. Additionally, future research directions for the development of such high-performance Mg alloy sheets are suggested. We hope that this review can provide some insightful information for researchers who are committed to fabricating high-performance Mg alloys for lightweight structural applications in the transportation industry, so as to improve fuel efficiency and reduce climate-changing and health-compromising emissions.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The aim of this study is to evaluate the microstructures, tensile lap shear strength, and fatigue resistance of 6022-T43 aluminum alloy joints welded via a solid-state welding technique-ultrasonic ...spot welding (USW)-at different energy levels. An ultra-fine necklace-like equiaxed grain structure is observed along the weld line due to the occurrence of dynamic crystallization, with smaller grain sizes at lower levels of welding energy. The tensile lap shear strength, failure energy, and critical stress intensity of the welded joints first increase, reach their maximum values, and then decrease with increasing welding energy. The tensile lap shear failure mode changes from interfacial fracture at lower energy levels, to nugget pull-out at intermediate optimal energy levels, and to transverse through-thickness (TTT) crack growth at higher energy levels. The fatigue life is longer for the joints welded at an energy of 1400 J than 2000 J at higher cyclic loading levels. The fatigue failure mode changes from nugget pull-out to TTT crack growth with decreasing cyclic loading for the joints welded at 1400 J, while TTT crack growth mode remains at all cyclic loading levels for the joints welded at 2000 J. Fatigue crack basically initiates from the nugget edge, and propagates with "river-flow" patterns and characteristic fatigue striations.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The occurrence of adiabatic shear bands, as an instability phenomenon, is viewed as a precursor to failure caused by instability at high strain rates. Metastable β titanium alloys are extensively ...utilized due to their excellent mechanical properties, which are often subjected to high strain rate loads in service conditions. Understanding and studying their adiabatic shear instability behavior is thus crucial for preventing catastrophic failure and enhancing material performance. In this study via detailed microstructural analyses in the adiabatic shear region of a Ti-10V-2Fe-3Al alloy subjected to high strain rates, it was observed that α″ martensitic transformation and nano-twinning plus β-to-α phase transformation with α″ martensite as an intermediate phase occurred, in addition to substantial fine grains. The grain refinement mechanisms were mainly related to dynamic recovery dominated by dislocation migration alongside severe plastic deformation.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The crystal structures, stability, mechanical properties and electronic structures of Nb-free and Nb-doped Ti-Al intermetallic compounds were investigated via first-principles calculations. Seven ...components and eleven crystal configurations were considered based on the phase diagram. The calculated results demonstrate that hP8-Ti
Al, tP4-TiAl, tP32-Ti
Al
, tI24-TiAl
, tI16-Ti
Al
, tI24-Ti
Al
, and tI32-TiAl
are the most stable phases. Mechanical properties were estimated with the calculated elastic constants, as well as the bulk modulus, shear modulus, Young's modulus, Poisson's ratio and Pugh's ratio following the Voigt-Reuss-Hill scheme. As the Al content increases, the mechanical strength increases but the ductility decreases in the Ti-Al compounds. This results from the enhanced covalent bond formed by the continuously enhanced Al-
hybrid orbitals and Ti-3
orbitals. Nb doping (~5 at.% in this study) keeps the thermodynamical and mechanical stability for the Ti-Al compounds, which exhibit slightly higher bulk modulus and better ductility. This is attributed to the fact that the Nb 4
orbitals locate near the Fermi level and interact with the Ti-3
and Al-3
orbitals, improving the metallic bonds based on the electronic structures.
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The purpose of this investigation was to study the low-cycle fatigue (LCF) behavior of a newly developed high-pressure die-cast (HPDC) Al-5.5Mg-2.5Si-0.6Mn-0.2Fe (AlMgSiMnFe) alloy. The effect of ...heat-treatment in comparison with its as-cast counterpart was also identified. The layered (α-Al + Mg2Si) eutectic structure plus a small amount of Al8(Fe,Mn)2Si phase in the as-cast condition became an in-situ Mg2Si particulate-reinforced aluminum composite with spherical Mg2Si particles uniformly distributed in the α-Al matrix after heat treatment. Due to the spheroidization of intermetallic phases including both Mg2Si and Al8(Fe,Mn)2Si, the ductility and hardening capacity increased while the yield stress (YS) and ultimate tensile strength (UTS) decreased. Portevin–Le Chatelier effect (or serrated flow) was observed in both tensile stress–strain curves and initial hysteresis loops during cyclic deformation because of dynamic strain aging caused by strong dislocation–precipitate interactions. The alloy exhibited cyclic hardening in both as-cast and heat-treated conditions when the applied total strain amplitude was above 0.4%, below which cyclic stabilization was sustained. The heat-treated alloy displayed a larger plastic strain amplitude and a lower stress amplitude at a given total strain amplitude, demonstrating a superior fatigue resistance in the LCF regime. A simple equation based on the stress amplitude of the first and mid-life cycles ((Δσ/2)first, (Δσ/2)mid) was proposed to characterize the degree of cyclic hardening/softening (D): D=±(Δσ/2)mid − (Δσ/2)first(Δσ/2)first, where the positive sign “+” represents cyclic hardening and the negative sign “−“ reflects cyclic softening.
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