挤压后交叉轧制的镁合金薄板组织研究  

Microstructure of Magnesium Alloy Thin Plate Cross-rolled after Extrusion

作　　者：张青来[1] 胡永学[1] 王粒粒[1] 孙毓蔚[2] 周娅莉[2] 

机构地区：[1]江苏大学材料科学与工程学院,江苏镇江212013 [2]宝鸡钛业股份有限公司,陕西宝鸡721014

出　　处：《热加工工艺》2007年第9期1-5,共5页Hot Working Technology

基　　金：国家"八六三"计划资助项目(2003AA331120);江苏大学资助项目(05JDG009)

摘　　要：研究了退火制度对挤压后交叉轧制的镁合金薄板组织结构影响。结果表明:挤压+交叉热轧组织是由混晶组织还是由含有板条状组织组成,主要取决于挤压板的组织;在温度大于350℃,保温时间大于60min的退火制度下少数的粗大等轴晶作为异常长大时的“核心”,吞噬周围小晶粒,使混晶组织转变成粗大等轴晶组织,即挤压组织的“遗传性”;挤压薄板或板坯时挤压比、温度、挤压速度等因素是镁合金获得均匀等轴晶组织、避免出现混晶组织及板条状组织的保证;最佳退火制度:保温温度250￣300℃,保温时间20￣30min,此时合金由分布均匀、细小等轴晶组成,具有最佳温拉深成形性能。The influence of different annealing process on microstructure of magnesium alloy thin plate cross-rolled after extrusion was studied, The result shows that the structure after extrusion plus cross-hot-rolling consists of the mixed grain structure or the lath structure. The final structure depends on the thin plate structure after extrusion. When the annealing temperature is higher than 350℃ and the holding time is more than 60min, a few large equiaxed grains become the cores of abnormal grain growth. They phagocyte near grains and make the mixed grain structure change to the large equiaxed grain structure. This is called as extrusion structure heredity. Extrusion ratio,extrusion temperature and extrusion speed are the assurances of obtaining equal equiaxed grain structure. And the mixed grain structure and the lath structure could be avoided, The best annealing process： the heating temperature 250-300℃, and the holdiing time 20-30min. In these process the alloy consists of equiaxed and refined grains, It has the best formability of hot drawing.

关 键 词：镁合金 挤压 轧制 温拉深 退火 

分 类 号：TG146.22[一般工业技术—材料科学与工程]