摘要
通过金相显微组织观察和断口SEM分析,研究了热处理对挤压AZ91镁合金拉伸变形与断裂行为的影响。结果表明:AZ91镁合金固溶态与挤压态相比抗拉强度变化不大,但伸长率有较大幅度的提高,晶粒尺寸有所增大;时效峰值态的抗拉强度与固溶态相比有一定的提高,但伸长率有较大幅度的降低,合金固溶时效处理后伴有强化相粒子析出。AZ91合金挤压态和固溶态的断面都有韧窝特征,为微孔形核的韧性断裂机制,而在时效峰值态的断面上则呈现出了韧性与脆性混合断裂的特征。
The effects of heat treatment on the microstructure, tensile deformation and fracture behavior of AZ91 magnesium alloy as-extruded were analyzed and studied by OM and SEM. The results show that comparing as-solution with as-extruded, the tensile strength of AZ91 alloy hardly changes, but its ductility and grain size increase significantly; comparing as-aged with as-solution,the tensite strength increases a litte,but its ductility reduces,with strengthening phase precipitating after solution and aging treatment.The fracture surface of AZ91 as-extruded and as-solution have dimple characteristic,and their fracture mechanism is ductile fracture.However, the fracture mechanism of AZ91 alloy as-aged changes from typical ductile tearing to mixture of ductile and brittle.
出处
《热加工工艺》
CSCD
北大核心
2006年第20期10-12,共3页
Hot Working Technology
基金
湖南省重大专项计划基金资助项目(04GK1008-1)
关键词
变形镁合金
挤压
热处理
拉伸
断裂
wrought magnesium alloy
as-extruded
heat treatment
tension
fracture
