挤压变形Mg-x%Al-3%Ni合金的低周疲劳行为  

LOW-CYCLE FATIGUE BEHAVIOR OF AS-EXTRUDED Mg-x%Al-3%Ni ALLOYS

作　　者：陈立佳[1] 王鑫[1] 智莹[1] 徐颜武[1] 

机构地区：[1]沈阳工业大学材料科学与工程学院,沈阳110178

出　　处：《金属学报》2009年第7期856-860,共5页Acta Metallurgica Sinica

基　　金：辽宁省自然科学基金资助项目20072039~~

摘　　要：通过对挤压变形Mg-x%Al-3%Ni(x=4,5,6,7,质量分数)合金进行总应变控制模式的室温疲劳实验,研究了不同Al含量的挤压变形Mg-x%Al-3%Ni合金的循环应力响应、疲劳寿命和循环应力-应变行为.结果表明:不同Al含量的挤压变形Mg-x%Al-3%Ni合金均表现为循环应变硬化;挤压变形Mg-x%Al-3%Ni合金的应变疲劳寿命与塑性应变幅、弹性应变幅间的关系分别服从Coffin-Manson和Basquin关系式.Due to the low density, high specific strength and stiffness, magnesium alloys are being considered for automotive and aerospace applications. The structural applications of magnesium components need a decent low cycle fatigue performance, because cyclic loading is often encountered. In order to identify the low cycle fatigue behavior of the newly developed Mg-x%Al-3%Ni（x=4, 5, 6, 7, mass fraction） extruded magnesium alloys with different contents of Al, the total strain-controlled low-cycle fatigue tests were performed at room temperature. The cyclic stress response, strain fatigue life and cyclic stress-strain behaviors were investigated for the hot extruded Mg-x%Al-3%Ni alloys. The results of the low cyclic fatigue tests show that the hot extruded Mg-x%Al-3%Ni alloys exhibit the cyclic strain hardening during fatigue deformation. The dependences of the strain fatigue life on plastic strain amplitude and elastic strain amplitude can be described by the Coffin Manson and Basquin equations, respectively. In the hot extruded Mg-x%Al-3%Ni alloys with different contents of Al, the extruded Mg-x%Al-3%Ni alloy gives the longest fatigue life and the highest fatigue resistance. In addition, a linear relation between the cyclic stress amplitude and cyclic strain amplitude can be noted for the hot-extruded Mg-x%Al-3%Ni alloys.

关 键 词：Mg-x%Al-3%Ni合金 热挤压 循环应力响应 疲劳寿命 循环应力 -应变 

分 类 号：TG146.2[一般工业技术—材料科学与工程]