Ce对AZ91D镁合金力学性能与阻尼性能的影响

Effects of Ce on Mechanical Properties and Damping Capacity of AZ91D Magnesium Alloy

为了提高AZ91D 镁合金的力学性能与阻尼性能,利用OM(光学金相显微镜)和XRD 分析了金属型铸造不同Ce 含量AZ91D 合金的显微组织和相组成,测试了室温力学性能,用悬臂梁技术测量了其阻尼性能。结果表明,AZ91D合金中加入一定量Ce 后生成的Al4Ce 相被推移到生长界面,阻碍枝晶的自由生长,从而细化合金铸态组织;Ce 能提高AZ91D 合金室温抗拉强度,而对其屈服强度和延伸率影响不大,Ce 能提高合金的阻尼性能;AZ91D-0.7%Ce 合金晶粒细化效果佳,力学性能较理想,阻尼性能最高;合金的阻尼行为可用Granato-Lücke 理论来解释。

In order to improve mechanical properties and damping capacity of AZ91D magnesium alloy, the microstructures and phases of AZ91D alloys cast by a permanent mould with various Ce contents were analyzed by using Optical Microscope and XRD. Their mechanical properties at ambient temperature were tested, and their damping capacity was measured by cantilever beam technique. The results show that Al4Ce phase formed in AZ91D alloys after adding a certain quantity of Ce is pushed into a growth interface, hinders the dendrite from growing freely and refines microstructures of the as-cast alloys. Cc can improve tensile strength of AZ91D alloy at ambient temperature, while it has little influences on their yield strength and elongation. Cc can improve damping capacity of AZ91D alloy. AZ91D-0.7%Ce alloy has good refinement effect, relatively ideal mechanical properties and the highest damping capacity. The damping behavior of the alloys can be explained by the theory of Granato and Locke.