Hot Deformation Behavior and Microstructures Evolution of GNP-Reinforced Fine-Grained Mg Composites

作     者：Hengrui Hu Jiayu Qin Yunpeng Zhu Jinhui Wang Xiaoqiang Li Peipeng Jin Hengrui Hu;Jiayu Qin;Yunpeng Zhu;Jinhui Wang;Xiaoqiang Li;Peipeng Jin

作者机构：Qinghai Provincial Key Laboratory of New Light AlloysQinghai UniversityXining 810016China Qinghai Provincial Engineering Research Center of High Performance Light Metal Alloys and FormingQinghai UniversityXining 810016China Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China School of Material Science and EngineeringLanzhou University of TechnologyLanzhou 730050China 

出 版 物：《Acta Metallurgica Sinica(English Letters)》 (金属学报（英文版）)

年 卷 期：2024年第37卷第3期

页      面：407-424页

核心收录：

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

基　　金：supported by the Qinghai Provincial Science and Technology Program (No.2020-ZJ-707) the Financial supports from the Natural Science Foundation of China (No.52261016). 

主　　题：GNPs Mg composite Hot deformation behavior Constitutive equations Microstructure evolution Dynamic recrystallization 

摘      要：Graphene nanoplates(GNPs)-reinforced magnesium matrix composites have been attracted great attention.However,knowledge is lack for the hot deformation behavior of GNP-reinforced magnesium(GNPs/Mg)composite.In this study,the fine-grained GNPs/Mg composite was fabricated by powder metallurgy process followed by extrusion.The hot deformation behavior,microstructure evolution and dynamic recrystallization(DRX)mechanism of fine-grained GNPs/Mg composite were investigated by hot compression test and electron back-scatter diffraction(EBSD).The hot compression tests of the composite were conducted at temperatures between 423 and 573 K with the strain rates from 0.001 to 1 s^(-1).The strain compensated power law equation was established to describe the hot deformation behavior of the composites.The stress exponent and activation energy of the composite are 7.76 and 83.23 kJ/mol,respectively,suggesting that the deformation mechanism is grain boundary slip controlled dislocation climb creep.The abnormally high stress exponent and activation energy are unattainable in the composite due to the fine grain size of the composites and the absence of Zener pinning and Orowan effects of GNPs reinforcement.The grain size increases with the decrease in Zener-Hollomn(Z)parameter,which can be well fitted by power-law relationship.With the increase in grain size and decrease in Z parameter,the geometrically necessary dislocation density decreases,which shows the approximately power-law relationship.A random and weak texture was formed after hot compression.The discontinuous dynamic recrystallization and continuous dynamic recrystallization mechanism dominated the DRX behavior at 473 K/0.001 s^(-1) and 573 K/0.001 s^(-1),respectively.