Mg-12Gd-3Y-0.5Zr镁合金的不同疲劳行为  

Different Fatigue Behaviors of Mg-12Gd-3Y-0.5Zr Magnesium Alloy

作　　者：杨晓明[1] 杨帆[1] 尹树明[1] 王渠东[2] 吴世丁[1] 张哲峰[1] 李守新[1] 

机构地区：[1]中国科学院金属研究所沈阳材料科学国家实验室,沈阳110016 [2]上海交通大学轻合金精密成型国家工程研发中心,上海200020

出　　处：《机械工程材料》2011年第4期41-45,68,共6页Materials For Mechanical Engineering

摘　　要：对轧制态Mg-12Gd-3Y-0.5Zr镁合金的室温低周、超高周疲劳,高温等温疲劳以及热机械疲劳性能进行了研究,并对其疲劳失效机制进行了分析。结果表明:对室温低周疲劳、超高周疲劳来说,其失效机制主要是夹杂或大的第二相引起的疲劳开裂;对于低周疲劳,裂纹萌生于表面或亚表面,而对于超高周疲劳,裂纹起源于内部;该合金的高温等温疲劳与热机械疲劳断裂裂纹都萌生于表面,其疲劳机制为循环滑移和氧化物夹杂共同作用;该合金在室温到200℃有良好的抗拉强度与疲劳强度;反相位热机械疲劳寿命比同相位的高。Room temperature low cycle fatigue, very high cycle fatigue, high temperature isothermal fatigue and thermo-mechanical fatigue properties of the as-rolled Mg-12Gd-3Y-0. 5Zr magnesium alloy were investigated. The fatigue failure mechanism was analyzed. The results show that for room temperature low cycle fatigue and very high cycle fatigue, the failure was caused by the fatigue cracks resulted from the inclusions or large-sized secondary phases. The cracks initiated from the surface or sub-surface for low cycle fatigue, however, for very .high cycle fatigue the internal cracking was the initiation. Both high temperaturei sothermal fatigue crack and thermo- mechanical fatigue crack originated from the surface. The interaction of cyclic slip and oxide inclusions was the main fatigue mechanism. The alloy had excellent tensile strength and fatigue strength from room temperature to 200℃. The opposed phase thermo-mechanical fatigue lifetime was longer than the in-phase one thermo-mechanical fatigue lifetime.

关 键 词：镁合金 低周疲劳 超高周疲劳 等温疲劳 热机械疲劳 疲劳机制 

分 类 号：TG113.25[金属学及工艺—物理冶金]