等径角变形AZ31镁合金的低周疲劳行为  

Low-cycle Fatigue Behavior of AZ31 Magnesium Alloy Produced by Equal Channel Angular Pressing

作　　者：武艳军[1] 朱荣[2] 

机构地区：[1]南京交通职业技术学院机电工程系,南京211188 [2]南京理工大学材料科学与工程系,南京210094

出　　处：《材料导报》2013年第22期104-107,共4页Materials Reports

基　　金：院级科研项目(JY1208)

摘　　要：通过恒应变控制疲劳实验,比较了常规挤压与等径角变形AZ31镁合金的疲劳寿命、表面变形形貌和疲劳断口。结果表明,等径角变形AZ31镁合金在疲劳过程中表现出明显的循环软化,且应变幅越大,软化越显著;晶粒在循环过程中发生再结晶行为,其长轴沿着等径角变形的剪切方向;等径角变形工艺可以显著延长镁合金的低周疲劳寿命,归因于疲劳延性系数的增加;由于裂纹尖端的疲劳塑性区尺寸较小,等径角变形合金断口表面较为平坦。The strain fatigue life, surface deformation morphology and fatigue fractography of AZ31 magnesium alloy produced by conventional extrusion and equal channel angular pressing （ECAP） at room temperature were inves tigated by uniaxial strain-controlled cyclic loading experiments. The results showed that the ECAP samples exhibited cyclic softening, and the softening effect increased with increasing total strain amplituderecrystallization occurred during the cyclic process, and the direction of larger axis of recrystallized grains was parallel to the shear direction of the ECAP. The longer fatigue life of the alloys produced by ECAP compared with the conventionally extruded ones was reflected in the much higher fatigue ductility coefficient. Because of small reverse plastic zone size, the fracture surface of ECAP alloy was rather flat.

关 键 词：AZ31镁合金 低周疲劳 等径角变形 疲劳寿命 

分 类 号：TG113.26[金属学及工艺—物理冶金]