(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院 長沙 410083；
2. 湖南工學(xué)院 機(jī)械工程系 衡陽 421002)
摘 要: 研究Mg-8Gd-3Y-0.6Zr合金熱壓縮過程的動(dòng)態(tài)再結(jié)晶規(guī)律。對該合金在變形溫度為623~773 K、應(yīng)變速率為0.01~1 s−1條件下進(jìn)行單向壓縮實(shí)驗(yàn)，用金相顯微鏡、場發(fā)射掃描電子顯微鏡及織構(gòu)測試儀對壓縮后的合金組織與晶體取向進(jìn)行分析。結(jié)果表明：曲線的峰值應(yīng)力、穩(wěn)態(tài)流動(dòng)應(yīng)力均隨Zener-Hollomon (Z)參數(shù)的增加而增加；變形溫度的升高以及應(yīng)變速率的提高均能減弱{0001}基面織構(gòu)，強(qiáng)化 柱面織構(gòu)；動(dòng)態(tài)再結(jié)晶晶粒尺寸隨Z參數(shù)的增加而減小。根據(jù)實(shí)驗(yàn)結(jié)果，該合金在熱軋時(shí)ln(Z)宜控制在28~32之間，變形溫度在723~773 K之間。
關(guān)鍵字: 鎂合金；熱壓縮；動(dòng)態(tài)再結(jié)晶；Zener-Hollomon參數(shù)；織構(gòu)
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Department of Mechanical Engineering, Hunan Institute of Technology, Hengyang 421002, China）
Abstract:The regularity of dynamic recrystallization in Mg-8Gd-3Y-0.6Zr alloy during hot-compression was investigated. For this purpose, the uniaxial compression was conducted at different deformation temperatures (from 623 K to 773 K) and various strain rates (from 0.01 s−1 to 1 s−1). The microstructure and macrotexture after compression were studied by optical microscope (OM), scanning electron microscopy (SEM) and X-ray texture measurement. The results show that the peak stress and the steady-state flow stress become higher with increasing Zener-Hollomon parameter (Z); Increasing deformation temperature or strain rate can weaken the {0001} basal texture and strengthen the prismatic texture; the grain size of dynamic recrystallization becomes smaller with increasing Z parameter. Therefore, ln(Z) ranging in 28−32 and the deformation temperature ranging in 723−773 K are proposed for hot-rolling of Mg-8Gd-3Y-0.6Zr alloy.
Key words: magnesium alloy; hot-compression; dynamic recrystallization; Zener-Hollomon parameter; macrotexture
