固相再生AZ31B镁合金的组织与力学性能（英文）

Microstructure and Mechanical Properties of AZ31B Magnesium Alloy Prepared by Solid State Recycling

在不同的挤压温度和挤压比下,将AZ31B镁合金机加屑冷压后热挤压固结而再生镁合金。与铸锭挤压合金对比,从动态再结晶组织与屑间结合情况两个主要方面分析了加工工艺对再生合金力学性能的影响。随着挤压温度升高,再生合金的极限抗拉强度和延伸率先增加而后降低。随挤压温度升高,晶粒长大与屑间结合增强的相反作用共同导致了再生合金力学性能的变化。当挤压比从4:1增加到44:1,晶粒细化且屑间结合增强,使再生合金的抗拉强度增加。而当挤压比大于25:1时,由于显著的形变强化作用导致延伸率下降。

Machined chips of AZ31B magnesium alloy were consolidated by cold pressing followed by hot extruding at different processing temperatures and extrusion ratios.Compared with ingot extruding alloy,the influences of processing technique on mechanical properties of recycled alloys were analyzed from two main aspects involving the dynamic recrystallization microstructure and the bonding condition between chips.Results show that with the increasing extrusion temperature,the ultimate tensile strength and elongation to failure of the recycled alloys firstly increase and then decrease.The combined action of grain growth and improvement of the bonding between chips with the increasing extrusion temperature results in the variations of mechanical properties of the recycled alloy.With the extrusion ratio increasing from 4：1 to 44：1,the grain is refined,and the bonding between chips is enhanced.This contributes to the increased ultimate tensile strength of recycled alloy.Whereas elongation to failure decreases when extrusion ratio is higher than 25：1 due to the significant deformation strengthening.