定向凝固AZ31镁合金晶粒取向及力学性能研究

Study on the Crystal Orientations and Mechanical Properties of AZ31 Magnesium Alloy Produced by Directional Solidification

采用自行设计的定向凝固装置制备了AZ31镁合金铸件,通过金相观察、XRD分析和室温压缩试验,研究定向凝固工艺对AZ31镁合金晶粒取向和常温力学性能的影响。结果表明:定向凝固制备的AZ31镁合金铸件具有柱状晶组织,第二相呈球状弥散分布于晶粒内部。由于温度梯度的影响,晶体规律性地定向生长,呈现较明显的[1010]择优取向。该铸件在常温力学性能和塑性成形性能上表现出各向异性的特点。

AZ31 magnesium alloy is prepared by self-designed equipment. By the analysis of microstructure, XRD pattern and the compressing experiment at room temperature （ RT ）, the effects of the directional solidification technique on crystal orientations and mechanical properties at RT of AZ31 magnesium alloy are studied. The experiment reveals that columnar structures form with this technique and the second spherical phase distribute equally in the matrix. During the process, crystals grow regularly in some direction and show an apparent [1010] orientation preference due to the effect of temperature gradient. Moreover, the RT mechanical properties and plastic deformation show anisotropy.