Effect of ECAP process on liquid distribution of AZ80M alloy during semi-solid isothermal heat treatment  

等径角挤压对AZ80M合金在半固态等温加热过程中液相分布的影响

作　　者：Ling-ling FAN Ming-yang ZHOU Yang-yang GUO Yu-wen-xi ZHANG Gao-feng QUAN 范玲玲;周明扬;郭阳阳;张钰雯茜;权高峰(西南交通大学,材料科学与工程学院,材料先进技术教育部重点实验室,成都610031;中国核动力研究设计院,核反应堆系统设计技术重点实验室,成都610213)

机构地区：[1]Key Laboratory of Advanced Technologies of Materials,Ministry of Education,School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China [2]Science and Technology on Reactor System Design Technology Laboratory,Nuclear Power Institute of China,Chengdu 610213,China

出　　处：《Transactions of Nonferrous Metals Society of China》2021年第6期1599-1611,共13页中国有色金属学报（英文版）

基　　金：supported by Key Development Project of Sichuan Province(Grant No.2017GZ0399)。

摘　　要：Two kinds of semi-solid samples of AZ80−0.2Y−0.15Ca(wt.%)(AZ80M)magnesium alloy were prepared by semi-solid isothermal heat treatment of materials with and without equal channel angular pressing(ECAP)process.The microstructures of initial and semi-solid treated samples were compared and analyzed.The results showed a significant difference in the liquid phase distribution between three-pass ECAP processed(3P)and as-received samples during the isothermal heating process.The semi-solid 3P sample showed a more uniform liquid distribution due to its smaller dihedral angle.Besides,the coarsening processes of solid grains of as-received and 3P samples were dominated by the coalescence and Ostwald ripening mechanism,respectively.The difference of coarsening processes was mainly related to the proportion of the high-angle grain boundaries in materials,which further affected the evolution behavior of the liquid pools.将经过等径角挤压(ECAP)和未经ECAP的AZ80−0.2Y−0.15Ca(质量分数,%)(AZ80M)合金试样进行半固态等温加热处理,得到两种半固态坯料。对两种坯料的在半固态等温加热处理前后的显微组织进行比较和分析。研究结果表明,在半固态等温加热处理中,经过3道次ECAP(3P)后的试样与初始挤压态试样的液相分布明显不同。半固态处理后的3P试样具有更均匀的液相分布,这是因为其半固态系统中具有更小的二面角。另外,初始挤压态试样和3P试样的固相晶粒粗化过程分别由合并机制和奥斯瓦尔德熟化机制主导。这两种材料在半固态过程中显示出的不同粗化机制主要与大角晶界的占比有关,随着半固态过程的进行,不同的粗化机制会进一步影响液池的演变行为。

关 键 词：AZ80M equal channel angular pressing semi-solid microstructure liquid phase distribution coarsening mechanism 

分 类 号：TG376[金属学及工艺—金属压力加工] TG146.22[一般工业技术—材料科学与工程]