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

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

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Graphene nanoplates(GNPs)-reinforced magnesium matrix composites have been attracted great attention.However,knowl-edge 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.

GNPsMg compositeHot deformation behaviorConstitutive equationsMicrostructure evolutionDynamic recrystallization

Hengrui Hu、Jiayu Qin、Yunpeng Zhu、Jinhui Wang、Xiaoqiang Li、Peipeng Jin

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Qinghai Provincial Key Laboratory of New Light Alloys,Qinghai University,Xining 810016,China

Qinghai Provincial Engineering Research Center of High Performance Light Metal Alloys and Forming,Qinghai University,Xining 810016,China

Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China

School of Material Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China

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Qinghai Provincial Science and Technology ProgramNatural Science Foundation of China

2020-ZJ-70752261016

2024

金属学报(英文版)
中国金属学会

金属学报(英文版)

CSTPCD
影响因子:0.77
ISSN:1006-7191
年,卷(期):2024.37(3)
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