Effects of thermomechanical processing on the microstructure, texture and mechanical properties of a Mg-Gd-based alloy

Abstract The effect of thermomechanical processing on the microstructure, texture and mechanical properties of a Mg-5.5Gd-3.0Y-1.0Nd-1.0Zr (wt.%) alloy was investigated using optical microscopy, uniaxial tensile testing, hardness testing, scanning electron microscopy, transmission electron microscopy, texture testing and X-ray diffraction. An overaging treatment before extrusion was introduced to affect the dynamic recrystallization process of the alloy. The results indicate that a substantial amount of β equilibrium phases with the composition of Mg5.05RE (RE: rare earth) precipitated from the matrix during the aging process prior to extrusion. Compared to the counterpart with no precipitates, the dynamic recrystallization process was promoted by the mechanism of particle-stimulated nucleation, which led to the formation of uniform fine grains and weakened texture in the extruded rod. Samples with an ultimate tensile strength of 324 MPa and a good elongation of 20.5% were obtained. The good ductility was attributed to the uniform fine grains and the modified texture.

[1]  Ke Liu,et al.  Development of extraordinary high-strength-toughness Mg alloy via combined processes of repeated plastic working and hot extrusion , 2013 .

[2]  Jun Yu Li,et al.  Heat treatment and mechanical properties of a high-strength cast Mg–Gd–Zn alloy , 2016 .

[3]  Limin Wang,et al.  Microstructure and mechanical property of Mg-8.31Gd-1.12Dy-0.38Zr alloy , 2008 .

[4]  K. Kainer,et al.  Effect of rare earth elements on the microstructure and texture development in magnesium-manganese alloys during extrusion , 2010 .

[5]  Yun-lai Deng,et al.  Phase transformation in Mg–8Gd–4Y–Nd–Zr alloy , 2011 .

[6]  J. Yanagimoto,et al.  Constitutive descriptions and microstructure evolution of extruded A5083 aluminum alloy during hot compression , 2018, Materials Science and Engineering: A.

[7]  F. Pan,et al.  Role of Al modification on the microstructure and mechanical properties of as-cast Mg–6Ce alloys , 2015 .

[8]  R. Logé,et al.  Recrystallization behavior of multi-directionally forged over-aged and solution treated Al-Cu-Mg alloy during non-isothermal annealing , 2017 .

[9]  Tong Libo,et al.  The effect of Gd and Zn additions on microstructures and mechanical properties of Mg-4Sm-3Nd-Zr alloy , 2017 .

[10]  W. Ding,et al.  Microstructure evolution and mechanical properties of an ultra-high strength casting Mg–15.6Gd–1.8Ag–0.4Zr alloy , 2014 .

[11]  H. Hou,et al.  Effect of Ti addition on the microstructure and mechanical properties of cast Mg-Gd-Y-Zn alloys , 2017 .

[12]  W. Ding,et al.  Effect of initial microstructure on the dynamic recrystallization behavior of Mg–Gd–Y–Zr alloy , 2012 .

[13]  Dingfei Zhang,et al.  The influences of extrusion-shear process on microstructures evolution and mechanical properties of AZ31 magnesium alloy , 2017 .

[14]  R. Fu,et al.  A study on microstructure and mechanical properties of AA 3003 aluminum alloy joints by underwater friction stir welding , 2017 .

[15]  Shu-nong Jiang,et al.  Dynamic precipitation in a Mg–Gd–Y–Zr alloy during hot compression , 2015 .

[16]  Zhimin Zhang,et al.  Rotary extrusion as a novel severe plastic deformation method for cylindrical tubes , 2018 .

[17]  J. Robson,et al.  Particle effects on recrystallization in magnesium―manganese alloys: Particle―stimulated nucleation , 2009 .

[18]  Xingxing Xu,et al.  Effect of Sn addition on the microstructure and mechanical properties of Mg–6Zn–1Mn (wt.%) alloy , 2014 .

[19]  Yun-lai Deng,et al.  Effects of thermal treatment on microstructure and mechanical properties of a Mg-Gd-based alloy plate , 2016 .

[20]  Dingfei Zhang,et al.  Microstructure, texture and mechanical properties evolution of pre-twinning Mg alloys sheets during large strain hot rolling , 2016 .

[21]  J. Meng,et al.  Effect of Y for enhanced age hardening response and mechanical properties of Mg–Gd–Y–Zr alloys , 2007 .

[22]  R. Wu,et al.  Microstructure and mechanical properties of Mg–Gd–Dy–Zn alloy with long period stacking ordered structure or stacking faults , 2011 .

[23]  Yuntian Zhu,et al.  Grain refining and mechanical properties of AZ31 alloy processed by accumulated extrusion bonding , 2018 .

[24]  Huihui Yu,et al.  Hall-Petch relationship in Mg alloys: A review , 2017 .

[25]  B. Mordike,et al.  Magnesium: Properties — applications — potential , 2001 .

[26]  Xiangsheng Xia,et al.  Lubrication performance of MoS2 and SiO2 nanoparticles as lubricant additives in magnesium alloy-steel contacts , 2016 .

[27]  W. Ding,et al.  Microstructure evolution in a Mg–15Gd–0.5Zr (wt.%) alloy during isothermal aging at 250°C , 2006 .

[28]  Yan Feng,et al.  Development of high mechanical properties and moderate thermal conductivity cast Mg alloy with multiple RE via heat treatment , 2017, Journal of Materials Science & Technology.

[29]  Liming Peng,et al.  Microstructure and strengthening mechanism of high strength Mg–10Gd–2Y–0.5Zr alloy , 2007 .

[30]  S. Kamado,et al.  Enhanced age-hardening and formation of plate precipitates in Mg–Gd–Ag alloys , 2009 .

[31]  Song-Jeng Huang,et al.  Enhanced mechanical properties of Mg-Gd-Y-Zn-Mn alloy by tailoring the morphology of long period stacking ordered phase , 2018 .

[32]  T. Koizumi,et al.  Grain size effects in aluminum processed by severe plastic deformation , 2018 .

[33]  Zhike Peng,et al.  Grain refining mechanism in Mg–9Gd–4Y alloys by zirconium , 2005 .

[34]  S. Kamado,et al.  Fabrication of extraordinary high-strength magnesium alloy by hot extrusion , 2009 .

[35]  F. J. Humphreys,et al.  Recrystallization and Related Annealing Phenomena , 1995 .