Mg-4Sm-3Gd-0.5Zr合金的热变形行为及热加工图  

Hot deformation behavior and hot processing map of Mg-4Sm-3Gd-0.5Zr alloy

作　　者：常锴骞 王军用 张清[1] 李萍[2] 王莹[2] CHANG Kai-qian;WANG Jun-yong;ZHANG Qing;LI Ping;WANG Ying(School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471023,China;School of Civil Engineering,Luoyang Institute of Science and Technology,Luoyang 471023,China)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471023 [2]洛阳理工学院土木工程学院,河南洛阳471023

出　　处：《材料热处理学报》2024年第10期183-191,共9页Transactions of Materials and Heat Treatment

基　　金：河南省科技攻关计划项目(222102230112)。

摘　　要：通过熔炼铸造制备了Mg-4Sm-3Gd-0.5Zr合金,经均匀化处理(525℃×6 h)后,随后在变形温度为360~480℃、应变速率为0.01~1 s^(-1)条件下对其进行了热压缩实验,确定了合金发生动态再结晶时峰值应变和临界应变的关系,计算了合金的热变形激活能,构建并分析了合金的热变形本构方程和热加工图。结果表明:在热变形过程中合金有明显动态再结晶行为,其发生动态再结晶的峰值应变几乎都是临界应变的2.21倍,且合金的流变应力随着应变速率的升高和变形温度的降低而升高;采用热变形本构方程计算的合金热变形激活能Q为240.039 kJ/mol;合金的最佳加工区间为变形温度为420~480℃、应变速率为0.01~0.049 s^(-1),该区间内的能量耗散率η>30%且不发生失稳。Mg-4Sm-3Gd-0.5Zr alloy was prepared by melting and casting method,and homogenized at 525℃for 6 h,then the hot compression experiments were conducted on the alloy under the conditions of deformation temperatures of 360-480℃and strain rates of 0.01-1 s^(-1).The relationship between peak strain and critical strain during dynamic recrystallization of the alloy was determined,and the activation energy of hot deformation of the alloy was calculated.The hot deformation constitutive equation and hot processing map of the alloy were established and analyzed.The results show that the alloy has obvious dynamic recrystallization behavior during hot deformation,and the peak strain at which dynamic recrystallization occurs is almost 2.21 times of the critical strain.The flow stress of the alloy increases with the increase of strain rate and the decrease of deformation temperature.The hot deformation activation energy Q of the alloy calculated using the hot deformation constitutive equation is 240.039 kJ/mol.The optimal processing zone for the alloy is deformation temperature of 420-480℃and a strain rate of 0.01-0.049 s^(-1),and the energy dissipation rate is greater than 30%within this zone but without instability.

关 键 词：Mg-4Sm-3Gd-0.5Zr合金 热变形 本构方程 热加工图 

分 类 号：TG146.2[一般工业技术—材料科学与工程]