挤压态AZ31镁合金的疲劳行为研究  

Fatigue Behavior of As-extruded AZ31 Magnesium Alloy

作　　者：毛萍莉[1] 李扬[1] 刘正[1] 贾莹莹[1] 陈立佳[1] 

机构地区：[1]沈阳工业大学材料科学与工程学院

出　　处：《特种铸造及有色合金》2010年第3期213-215,共3页Special Casting & Nonferrous Alloys

基　　金：国家重点基础研究发展计划(973计划)资助项目(2007CB613705);辽宁省教育厅创新团队项目(2009T073)

摘　　要：通过外加总应变幅控制的疲劳试验和断口形貌分析,确定了挤压态AZ31镁合金的循环应力响应行为、循环变形行为、疲劳寿命行为和疲劳断裂机制。结果表明,在外加总应变幅控制的疲劳加载条件下,挤压态AZ31镁合金呈现明显的循环应变硬化现象和拉-压不对称循环变形现象,其弹性应变幅、塑性应变幅与断裂时的载荷反向周次之间的关系可分别用Basquin和Coffin-Manson公式来描述,断口上的疲劳裂纹的萌生和扩展均以穿晶模式进行。Behaviors of cyclic stress response and cyclic deformation,fatigue life as well as fracture mechanism were identified for as-extruded AZ31 magnesium alloy through total-strain-amplitude controlled fatigue testing and analysis on fracture surface of fatigued specimens.The results indicate that the as-extruded AZ31 alloy exhibits significant cyclic strain hardening and stretch-compression asymmetry in cyclic deformation,and the relationship between elastic strain amplitude,plastic strain amplitude and reversal to failure can be described by the Basquin and Coffin-Manson equations,respectively.In addition,it is found that fatigue cracks are generated and propagated in a transgranular mode.

关 键 词：镁合金 弹性应变幅 塑性应变幅 疲劳断裂 循环应力响应 循环变形 疲劳寿命 疲劳裂纹 

分 类 号：TG115.57[金属学及工艺—物理冶金]