性能的影响
(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)
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。
关键字: AZ91D合金；消失模铸造；振动凝固；Ce-Sb合金化
and properties of AZ91D magnesium alloy
via lost foam casting
（State Key Laboratory of Material Processing and Die and Mould Technology,
Huazhong University of Science and Technology, Wuhan 430074, China）
Abstract: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 fracture surface after Sb-Ce alloying have obvious plastic deformation.
Key words: AZ91D alloy; lost foam casting; vibration-freezing; Ce-Sb alloying
