Superplasticity of a friction stir processed overaged WE54 magnesium alloy

作     者：Oscar A.Ruano Marta Alvarez-Leal Alberto Orozco-Caballero Fernando Carreño 

作者机构：Physical Metallurgy DepartmentCENIM-CSICAv.Gregorio del Amo 828040 MadridSpain Department of R&D and programmesTechnology Centre of Metal-Mechanical and Transport(CETEMET).Avda.1°de Mayos/n.LinaresJaén2370Spain Department of Mechanical EngineeringChemistry and Industrial DesignPolytechnic University of MadridRonda de Valencia 328012MadridSpain 

出 版 物：《Journal of Magnesium and Alloys》 (镁合金学报（英文）)

年 卷 期：2022年第10卷第11期

页      面：3156-3166页

核心收录：

学科分类：0806[工学-冶金工程] 08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：Financial support from MINECO (Spain), Project MAT2015–68919-C3–1-R (MINECO/FEDER) CENIM, CSIC, for a contract funded by the aforementioned project MINECO for a FPI fellowship, number BES2013–063963 (MINECO/FEDER/ESF) 

主　　题：WE54 magnesium alloy Friction stir processing Processing severity Superplasticity Grain boundary sliding Solutes 

摘      要：The coarse-grained WE54 magnesium alloy was heat treated in order to have minimum hardness minimizing the effects of precipitates and solid solution. Friction stir processing(FSP) was applied in severe conditions to obtain fine, equiaxed and highly misoriented grains, with grain sizes even less than 1 μm. The high severity of processing demonstrated to have a strong impact in the microstructure. Consequently,the processed materials exhibited excellent superplasticity at the high strain rate 10^(-2)s^(-1), and temperatures between 300 and 400 ℃. The maximum tensile superplastic elongation of 756% was achieved at 400 ℃ thanks to the operation of grain boundary sliding mechanism(GBS). Besides the new data obtained through tensile testing, the paper deals with a transcendental question regarding the large differences in strain rate values at a given stress in the superplastic regime at maximum elongation compared to other magnesium-based alloys. With this is mind, 19 magnesium alloys from 22 different investigations were analyzed to give some light to this behavior that never was treated before. It is proposed that this behavior has to be attributed to the accommodation process, necessary for GBS to occur, which is hindered by reinforcing solutes.