Determining the characteristics of representative volume elements in severely deformed aluminum-matrix composite

Abstract

The accurate evaluation of the effective mechanical properties of composites mainly depends on the characteristics of representative volume elements (RVEs). This paper mainly investigates the RVE size. Additionally, the effect of volume fraction of reinforcement, the edge effect, and RVE types on the critical size are discussed. First, the Al/Ni multilayered composites were processed by nine cycles of the cross-accumulative roll bonding (CARB) method. Then, one type of RVEs was created based on cross-sectional micrographs of composites to consider their inhomogeneities. Another type was generated by using the random sequential adsorption (RSA) procedure. Thereafter, the homogenized effective elastic properties of both types of microstructure-based RVEs and RSA-based RVEs were computed and compared as a function of the volume fraction of Ni and RVE size. The results showed that by increasing the Ni fragments, the RVEs indicated stiffer elastic behavior. By increasing the volume fraction of Ni from 0.2 Vf to 0.8 Vf, the Poisson ratio decreased by 7 % and the elastic modulus increased by 83 % for RSA-based RVE. Regarding the size of microstructure-based RVE of Al/Ni (0.8 Vf), from the largest size (size 1) with a length of 575 μm and a width of 575 μm to the smallest size (size 5) with a length of 287.5 μm and a width of 287.5 μm, the elastic modulus and the Poisson ratio showed 16 % and 0.8 % decrease, respectively.