Creep mechanism and creep constitutive model of aluminum silicate short-fiber-reinforced magnesium matrix composite  

硅酸铝短纤维增强镁基复合材料的蠕变机制及蠕变本构模型（英文）

作　　者：田君[1] 石子琼[1] 

机构地区：[1]东莞理工学院机械工程学院,东莞523808

出　　处：《Transactions of Nonferrous Metals Society of China》2014年第3期632-640,共9页中国有色金属学报（英文版）

基　　金：Project(10151170003000002)supported by the National Science Foundation of Guangdong Province,China

摘　　要：By the constant stress tensile creep test method, creep tests were performed on aluminum silicate short fiber-reinforced AZ91D magnesium matrix composite with volume fraction of 30% and its matrix alloy AZ91D under different temperatures and stresses. The results indicate that the composite and the matrix have the same true stress exponent and true activation energy for creep, which are 3 and 144.63 kJ/mol, respectively. The creep of the composite is controlled by the creep of its matrix, which is mainly the controlling of viscous slip of dislocation, and the controlling of grain boundary slippage as a supplement. The creep constitutive model obtained from the experiment data can well describe the creep deformation pattern of the composite.利用常应力拉伸蠕变实验法对体积分数为30%的硅酸铝短纤维增强AZ91D镁基复合材料及其基体合金AZ91D在不同温度和应力下进行蠕变测试。结果表明:2种材料的真应力指数均为3,真蠕变激活能均等于144.63kJ/mol;复合材料的蠕变是由基体的蠕变控制,以位错黏滞性滑移控制为主,晶界滑移控制为辅。由实验数据获得的蠕变本构模型的经验公式能较好地描述复合材料的蠕变变形规律。

关 键 词：magnesium matrix composites threshold stress effective stress constitutive model 

分 类 号：TB331[一般工业技术—材料科学与工程]