Uniaxial Cyclic Deformation of Sicp/6061Al Alloy Composites and Its Time--Dependence
SiCp/6061Al合金复合材料的单轴循环变形行为及其时间相关特性

The uniaxial cyclic deformations of T6-treated 6061A1 alloy and SiC_p/6061Al alloy composites(14%,21% SiC_p)were studied experimentally at room temperature.The cyclic soften- ing/hardening features and ratcheting behaviors of unreinforced matrix and the composites were dis- cussed under the different loading conditions.It is shown that the strain cyclic characteristics and ratcheting behavior of the composites are similar to those of the un-reinforced matrix in macro-scale, namely,the ratcheting also occurs in the composites under asymmetrical stress cycling and the ratch- eting strain increases as the stress amplitude and mean stress increased;however,the addition of SiC_p increases the resistance of the composites to ratcheting,and the ratcheting strain decreases as the volume fraction of SiC_p increased;the ratcheting has great time-dependence,i.e.,the ratcheting strain depends on the stressing rate and peak stress hold time.Some significant conclusions are obtained, which is useful to construct a constitutive model to describe the cyclic deformations of the composites.