挤压变形Mg-Mn-Zn-Ce合金的低周疲劳行为  

Low-cycle fatigue behavior of as-extruded Mg-Mn-ZnCe magnesium alloy

作　　者：李学哲[1] 王鑫[1] 陈立佳[1] 吴崴[1] 

机构地区：[1]沈阳工业大学材料科学与工程学院

出　　处：《沈阳工业大学学报》2008年第2期187-190,共4页Journal of Shenyang University of Technology

基　　金：辽宁省科技厅重点实验室专项计划资助项目(2004404006)

摘　　要：针对稀土镁合金的疲劳行为进行研究,可为新型稀土变形镁合金的抗疲劳设计和合理利用提供可靠的理论依据.通过总应变幅控制的疲劳实验和断口形貌分析,确定了挤压变形Mg-Mn-Zn-Ce合金的循环变形行为和断裂机制.结果表明:对于挤压变形Mg-Mn-Zn-Ce合金而言,除在最低的外加总应变幅下呈现初期循环应变硬化,其后呈现循环稳定外,在其它外加总应变幅下均表现为循环应变硬化,且合金的弹性应变幅、塑性应变幅与断裂时的载荷反向循环周次之间的关系可分别用Basquin和Coffin-Manson公式描述.此外,疲劳裂纹的萌生和扩展均以穿晶方式进行.The investigation on fatigue behavior of magnesium alloys can provide a reliable theoretical foundation for both fatigue resistant design and reasonable application of new magnesium alloys containing rare earth.Through performing total strain-controlled fatigue tests and analysis on fracture surfaces of fatigued specimens,the cyclic deformation and fatigue life behaviors as well as fracture mechanism were identified for hot-extruded Mg-Mn-Zn-Ce alloy.The experimental results show that the hot-extruded Mg-Mn-Zn-Ce alloy exhibits significant cyclic strain hardening followed cyclic stability at the lowest total strain amplitude,while shows cyclic strain hardening at other total strain amplitudes.For the hot-extruded Mg-Mn-Zn-Ce alloy,the relations between elastic strain amplitude,plastic strain amplitude and reversals to failure can be described by Basquin and Coffin-Manson equations, respectively.In addition,it has been found that fatigue cracks initiate and propagate in a transgranular mode.

关 键 词：Mg-Mn-Zn-Ce合金 低周疲劳 循环应力响应 疲劳寿命 疲劳断裂 

分 类 号：TG113.255[金属学及工艺—物理冶金]