晶界形貌、织构对AZ31镁合金各向异性的影响

Effect of the boundary and textures of grains on anisotropy of AZ31 magnesium alloy

采用金相观察、织构分析、拉伸实验等方法,研究了变形工艺、晶界形貌及织构对AZ31镁合金屈服强度及延伸率各向异性的影响.结果表明:轧制过程会使晶粒拉长而产生平直晶界,当拉伸应力方向与平直晶界走向成45°时,AZ31镁合金总是表现出低屈服强度和高延伸率;除了织构之外,晶界形貌也在一定程度上影响着镁合金的力学性能;当拉伸应力与平直晶界走向成0°或90°时,基面滑移的Schmid因子和拉伸孪晶是影响镁合金力学性能的主要因素.

The effects of deformation process,grain boundary morphology and textures on the yield strength and elongation anisotropy of AZ31 magnesium alloy were investigated by using metallographic analysis,texture analysis and tensile test.Results show that rolling process can stretch grains and generate straight grain boundaries,when the direction of the tensile stress separated form straight grain boundaries by 45°,AZ31 magnesium alloy all ways has a lower yield strength and high elongation.Analysis indicates that in addition to the textures,the grain boundary morphology also affects the mechanical properties of magnesium alloys;when the direction of tensile stress separated form straight grain boundaries by 0° or 90°,basal slip Schmid factor and tensile twinning were the major factor affecting the mechanical properties of magnesium alloys.