变载条件下(Al_2O_3)_f增强铝合金复合材料的瞬时变形和回蠕变  

TRANSIENT STRAIN AND BACK CREEP OF (Al2O3)f REINFORCED Al ALLOY COMPOSITES UNDER LOAD CHANGE

作　　者：周清[1] 王浩伟[1] 黄明华[1] 

机构地区：[1]上海交通大学金属基复合材料国家重点实验室,上海200030

出　　处：《金属学报》2003年第3期325-328,共4页Acta Metallurgica Sinica

基　　金：国家自然科学基金59901006;上海市青年科技启明星计划资助项目

摘　　要：研究了由挤压铸造制备的体积分数为15％的Al2O3短纤维((Al2O3)f)增强ZL 109(Al-Si12-Cul-Mgl-Nil)复合材料在降载前后的蠕变行为.结果表明:降载后的蠕变可分为瞬时弹性和回蠕变两阶段.瞬时应变与通过测量弹性模量计算的弹性应变基本一致,而随松弛时间的延长,反方向的应变增大,回蠕变的速率减小;回蠕变的出现与纤维在复合材料中引起的偏差应力在降载后变为负值有关,用偏差应力的方法以及应力松弛可以较好地解释回蠕变规律.Creep behavior of 15% (Al2O3)(f) reinforced Al-Si12-Cu1-Mg1-Ni1 composites was studied using a loading change experiment. The unloading response is divided into two sections, transient deformation section and back creep sections. The 'transient strain is correspondent to the calculated value. according to the measured elastic modulus. The contract strain is increased with elongating the relaxation time, but the back creep rate is decreased. The back creep strain is related to the negative value of deviation stress due to the short fiber. The back creep behavior may be interpreted by the method of deviation stress.

关 键 词：铝基复合材料 AL2O3短纤维 变载荷 蠕变 偏差应力 

分 类 号：TB33[一般工业技术—材料科学与工程] TG118[金属学及工艺—物理冶金]