Effect of Multi-directional Forging Process on Microstructure and Properties of 20vol.% SiCw/6061Al Composites

In this study, we investigated the effect of multi-directional forging on the microstructure and mechanical properties of 20vol.% SiCw/6061Al composites. The results showed that the strength of forged workpiece did not decrease with the decrease of the whisker length. The improvement in the strength and fracture to elongation of multi-directional forged workpiece originated from the effective elimination of casting microstructural defects by the plastic deformation. In the free forged workpiece with an incremental pass strain, the average equivalent strain is smaller, and the strain distribution is more homogeneous with respect to that in the die-constrained forged workpiece with the same cumulative nominal strain. The heterogeneity in the hardness of die-constrained forged workpiece was mainly caused by the inhomogeneity of strain distribution. Besides, the multi-directional forging process with an increasing pass strain exhibits a bigger potential to improve the plasticity and homogeneity, and to decrease the anisotropy of forged workpiece.