挤压态定向凝固纯镁组织及其力学性能

Microstructure and Mechanical Properties of Extruded Directionally Solidified Pure Magnesium

本研究自行设计并制造了定向凝固设备,制备出具有粗大晶粒的纯镁铸锭,研究了定向凝固纯镁经过挤压后的组织与力学性能。研究结果表明:当挤压温度为573K,挤压比相同时,一般铸态纯镁的晶粒更细小,但晶粒的不均匀因子Z值更大。挤压比为10.2∶1时,定向凝固纯镁与一般铸态纯镁相比,有更高的屈服强度、抗拉强度和延伸率。当挤压比提高到25∶1时,一般铸态纯镁的强度和延伸率增长较快,延伸率高于定向凝固纯镁。

Pure magnesium with coarse columnar grains was manufactured using a self-designed directional solidification equipment,which an extrusion of the product followed.Microstructure and mechanical properties of the extruded directionally solidified pure magnesium are investigated.Results show that when the extrusion temperature is 573K and the extrusion ratio is the same,the crystal grains of the samples are generally fine,but the grain uneven factor(value Z)is larger.When the extrusion ratio is 10.2∶1,the yield strength,tensile strength and elongation are all higher than the as-cast pure magnesium.When the extrusion ratio is increased to 25∶1,the strength and elongation increased faster,and the elongation is higher than the as cast directionally solidified pure magnesium.