往复挤压Mg-4Al-2Si合金中Mg_2Si颗粒形貌与分布  

Morphological and Distribution Characteristics of Mg_2Si Particles in Mg-4Al-2Si Alloy Prepared by Reciprocating Extrusion

作　　者：郭学锋[1] 杨文朋[2] 宋佩维[2] 

机构地区：[1]河南理工大学材料科学与工程学院,河南焦作454000 [2]西安理工大学材料科学与工程学院,西安710048

出　　处：《材料工程》2011年第11期62-67,共6页Journal of Materials Engineering

基　　金：国家自然科学基金(50271054);教育部博士点基金(20070700003);河南省科技厅攻关资助项目(102102210031);河南省教育厅自然科学基金资助项目(2010A430008)

摘　　要：使用往复挤压细化Mg-4Al-2Si(AS42)合金组织,利用OM,SEM和TEM研究Mg2Si颗粒形貌和分布特征。结果表明,铸态AS42合金中Mg2Si颗粒呈共晶汉字状和初生块状。共晶Mg2Si经2道次往复挤压后全部破碎,且分布均匀。经6道次挤压后初生Mg2Si颗粒全部破碎,细小的Mg2Si颗粒已基本球化。往复挤压合金中Mg2Si颗粒尺寸遵循Weibull分布,颗粒平均尺寸、标准差和相对密度随挤压道次增加而提高,经过8道次挤压后分别为1.3μm、0.7μm和540%。Microstructure of as-cast Mg-4Al-2Si（AS42） alloy was refined by reciprocating extrusion（REX）,the morphologic and distribution characteristics of Mg2Si particles were investigated by employing optical microscopy,scanning electron microscopy,and transmission electron microscopy.The results show that the Mg2Si particles in as-cast AS42 alloy are in the forms of eutectic Chinese scripts and primary polyhedral particles.After 2-pass REX,all eutectic Mg2Si particles are broken and distributed uniformly.After 6-pass REX,all primary Mg2Si particles are broken and the fine Mg2Si particles are spheroidized basically.The distribution of the Mg2Si particles in the extruded alloy follows Weibull function.After 8-pass REX,the average size,uniformity and the relative density of Mg2Si particles are 1.3μm,0.7μm and 540%,respectively.

关 键 词：往复挤压 MG2SI 球化 WEIBULL分布 

分 类 号：TG379[金属学及工艺—金属压力加工]