振动和合金化对消失模铸造AZ91D组织与性能的影响  

Effects of vibration and alloying on microstructure and properties of AZ91D magnesium alloy via lost foam casting

作　　者：李继强[1] 樊自田[1] 王元庆[1] 董选普[1] 

机构地区：[1]华中科技大学材料成型及模具技术国家重点实验室,武汉430074

出　　处：《中国有色金属学报》2007年第7期1047-1052,共6页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(50275058);国家高技术研究发展计划资助项目(2007AA03Z113)

摘　　要：振动凝固和Ce-Sb复合微合金化都能明显细化消失模铸造AZ91D镁合金的铸态组织。经振动凝固的铸态组织特征与原始铸态的相差不大,复合微合金化后的细化效果更显著,且经Ce-Sb复合微合金化处理后在α-Mg基体上出现大量弥散分布的颗粒状CeSb相,在晶内和晶界分布着少量的Al11Ce3针状相。两种处理工艺都能使消失模AZ91D试样的抗拉强度和伸长率得到较大幅度提高,其中经Ce-Sb复合微合金化后的常温力学性能提高最大,两种方法都没有使消失模AZ91D试样的断裂方式发生明显改变,但Ce-Sb复合微合金化后的合金铸态断口具有明显的塑性变形特征。Vibration-freezing and adding 1.0%Ce-0.4%Sb can obviously refine the microstructure of lost foam cast AZ91D magnesium alloy. The characteristic of as-cast microstructure has a little difference from that of vibration-freezing. But the microstructure has smaller grain size after addition of microscale cerium and antimony. From SEM photographs of the samples after Sb-Ce alloying, it is found that a large number of granular CeSb phase distributes in the grain, and a little needle Al11Ce3 phase in both grain and boundary. Both the methods can improve the tensile strength and elongation of AZ91D alloy via LFC to a great extent. And the improved value is the largest by addition of Ce and Sb. Although they can＇t change the fracture mode of AZ91D alloy, SEM fractographs of tensile fi-acture surface after Sb-Ce alloying have obvious plastic deformation.

关 键 词：AZ91D合金 消失模铸造 振动凝固 Ce—Sb合金化 

分 类 号：TG146.2[一般工业技术—材料科学与工程]