挤压铸造大高径比铸件的凝固特性和组织  

Solidification Characteristics and Microstructure of Castings with Large Ratio of Height to Diameters in Squeezing Casting

作　　者：李晨希[1] 王宏[1] 李革 李淑梅[3] 

机构地区：[1]沈阳工业大学 [2]辽宁省凤城市教师进修学校 [3]辽东学院

出　　处：《特种铸造及有色合金》2006年第11期713-715,共3页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(50275098);辽宁省教育厅科学研究计划资助项目(05L294)

摘　　要：铸件的凝固特性和组织直接影响铸件的力学性能,用计算机模拟和试验的方法研究了大高径比挤压铸件的凝固特性和凝固组织。研究表明,铸件中压力分布极不均匀,靠近冲头处压力较大,凝固速度较快;增大压力导致晶粒细化并使其发生塑性变形;大高径比薄壁铸件的下部组织中出现分界面,界面两侧组织明显不同。Solidification characteristics and microstructure of squeezing castings with large ratio of height to diameter have been investigated by numerical simulation and experiments. The results show that pressure distribution in the squeezed castings with large ratio of height to diameter is very uneven, in which the higher pressure is exhibited at the position near to the punch so that faster solidification rate can be obtained. Pressure-increment can result in the refinement and the occurrence of plastic deformation of the grain. There exists interface at down-position microstructure of thin-walled parts with large ratio of height to diameter, where microstructure is obviously different in two sides.

关 键 词：挤压铸造 大高径比铸件 凝固 组织 

分 类 号：TG249.2[金属学及工艺—铸造]