AS41压铸镁合金的低周疲劳行为  

Low-cycle fatigue behavior of die-cast AS41 magnesium alloy

作　　者：李锋[1] 单飞虎[1] 车欣[1] 王鑫[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,沈阳110870

出　　处：《沈阳工业大学学报》2011年第5期510-515,共6页Journal of Shenyang University of Technology

基　　金：辽宁省教育厅重点实验室资助项目(2008S163)

摘　　要：为了探索AS41压铸镁合金在室温下的低周疲劳变形与断裂行为,分别对压铸态和固溶处理态的AS41镁合金进行了应变控制疲劳实验,并利用S-3400N型扫描电子显微镜对合金的低周疲劳断口形貌进行了观察与分析.结果表明,在低周疲劳加载条件下,合金均表现为循环应变硬化;合金的塑性应变幅、弹性应变幅与断裂时的载荷反向周次之间分别服从Coffin-M anson和Basqu in公式;AS41压铸镁合金经固溶处理后的组织比压铸态更均匀,强化相分布更弥散,在相同的外加总应变幅下表现出更高的疲劳寿命.断口形貌观察结果揭示,对于两种加工状态的AS41镁合金,疲劳裂纹均以穿晶方式萌生于试样表面并以穿晶方式扩展.In order to investigate the low-cycle fatigue and fracture behavior of die-cast AS41 magnesium alloy at room temperature,the strain-controlled fatigue experiments were performed for the die-cast AS41 alloy with as-received and solid solution treated states.The fracture surfaces of low-cycle fatigued specimens were observed and analyzed with an S-3400N scanning electron microscope.The experimental results show that the AS41 alloy exhibits the cyclic strain hardening under low-cycle loading condition.The relationship between plastic and elastic strain amplitudes as well as reversals to failure can be described by Coffin-Manson and Basquin equations,respectively.Compared with the as-received alloy,the die-cast AS41 alloy subjected to the solid solution treatment exhibits more homogeneous microstructure,more dispersive distribution of strengthening phases and longer fatigue lives at the same total strain amplitudes.In addition,the observation on the morphology of fracture surfaces reveals that for the AS41 alloy with two processing states,the fatigue cracks initiate transgranularly on the surface of fatigue specimens and propagate in a transgranular mode.

关 键 词：镁合金 压铸 固溶处理 显微组织 低周疲劳 循环应力响应 疲劳寿命 疲劳断裂 

分 类 号：TG146.2[一般工业技术—材料科学与工程]