Mg-9Gd-2Nd-0.8Al合金热压缩行为及热加工图
Hot Compression Behavior and Processing Map of Mg-9Gd-2Nd-0.8Al Alloy
张子延 1陈君 2陈晓亚 2李全安 2刘建鑫1
作者信息
- 1. 河南科技大学材料科学与工程学院,河南洛阳 471023
- 2. 河南科技大学材料科学与工程学院,河南洛阳 471023;有色金属新材料与先进加工技术省部共建协同创新中心,河南洛阳 471023
- 折叠
摘要
采用光学显微镜、扫描电镜研究了铸态和均匀化态的Mg-9Gd-2Nd-0.8Al合金的显微组织,然后用Gleeble-1500D热模拟试验机对均匀化态合金在变形温度350～500 ℃,应变速率0.003～1 s-1条件下进行了热压缩实验,计算了合金的变形激活能,构建并分析了合金的本构方程和热加工图.结果表明:铸态Mg-9Gd-2Nd-0.8Al合金主要由α-Mg基体和Mg5Gd,Mg41Nd5,Al2RE相组成,经均匀化处理后(510 ℃×12h),Mg5Gd和Mg41Nd5相基本溶解,A12RE相保持稳定.均匀化态合金的流变应力曲线表现出动态再结晶的特征,其流变应力和峰值应力随温度的升高或应变速率的降低而显著降低,合金的变形激活能为185.836kJ·mol-1.合金在本实验的变形条件范围内存在两个失稳区:变形温度350～375 ℃,应变速率0.003～0.012 s-1以及变形温度350～500 ℃,应变速率0.05～1 s-1,其最佳加工区域为变形温度445～500 ℃,应变速率0.003～0.01 s-1,合金在变形温度400 ℃,应变速率0.003 s-1条件下的再结晶方式以非连续动态再结晶为主.
Abstract
The microstructure of as-cast and homogenized Mg-9Gd-2Nd-0.8Al alloys was studied by an optical microscope and a scanning electron microscope.Then the hot compression experiment of homogenized alloy was carried out with Gleeble-1500D thermal simulation under the conditions of deformation temperature of 350-500 ℃ and strain rate of 0.003-1 s-1.The deformation activation energy of the alloy was calculated,and the constitutive equation and hot processing map of the alloy were constructed and analyzed.The results show that as-cast Mg-9Gd-2Nd-0.8Al alloy is mainly composed of α-Mg matrix and Mg5Gd,Mg41Nd5,A12RE phases.After homogeniza-tion treatment(510℃×12 h),Mg5Gd and Mg41Nd5 phases basically dissolve and A12RE phase remains stable.The flow stress curve of homogenized alloy shows the characteristics of dynamic recrystallization.The flow stress and peak stress decrease significantly with the increase of temperature or the decrease of strain rate.The defor-mation activation energy of the alloy is 185.836 kJ·mol-1.There are two instability zones within the deformation conditions of this test:deformation temperature of 350-375 ℃,strain rate of 0.003-0.012 s-1 and deformation temperature of 350-500℃,strain rate of 0.05-1 s-1.The best processing zone is deformation temperature of 445-500℃,strain rate of 0.003-0.01 s-1.The recrystallization mode of the alloy under the deformation tempera-ture of 400 ℃ and strain rate of 0.003 s-1 is mainly discontinuous dynamic recrystallization.
关键词
Mg-9Gd-2Nd-0.8Al合金/热压缩变形/本构方程/热加工图/微观分析Key words
Mg-9Gd-2Nd-0.8Al alloy/hot compression deformation/constitutive equation/hot processing map/microscopic analysis引用本文复制引用
基金项目
国家自然科学基金(51571084)
中原英才计划—中原青年拔尖人才项目(豫组通202144号)
河南省自然科学基金(222300420435)
出版年
2024
NETL
NSTL
万方数据