挤压态MB15镁合金的显微组织与力学性能研究

针对MB15镁合金在挤压温度为648 K,应变速率0.001s-1,挤压比9∶1的条件下进行挤压变形研究,通过对其变形后的组织特征分析和拉伸性能测试,光学显微组织研究表明MB15镁合金在挤压过程中发生动态再结晶;透射电镜组织研究表明机械孪晶、位错滑移和动态再结晶是材料变形的典型特征;扫描电镜组织研究表明挤压后的材料塑性明显增强.挤压变形后的MB15镁合金沿挤压方向的抗拉强度提高39.5％,屈服强度提高89.4％,延伸率提高25％,弹性模量提高6.7％.

A study of microstructures and properties of extruded MB15 magnesium alloy

Extrusion deformation tests of MB15 magnesium alloy are performed on the conditions of temperature 648 K, with strain rates 0. 001 s 1 and extrusion ratio 9 ： 1. The microstructures are analyzed and the properties test are performed. The results indicate that dynamic recrystallization （DRX） occurs during extrusion process by the optical microscopy. The TEM findings indicate that mechanical twinning, dislocation slip, and dynamic recrystallization are the typical deformation features. The SEM findings indicate that the ductility of the extruded alloy is enhanced obviously. Tensile properties of extruded MB15 alloy （along extrusion direction） are measured, and that the tensile strength, yield strength, specific elongation and elastic modulus are improved by 39.5%, 89.4%, 25% and 6.7%, respectively.