Effect of Casting and Additive Manufacturing on the Microstructure and Mechanical Property of Al-Cu Composites

Abstract

The TiB2 reinforced Al-5Cu composites was manufactured by additive manufacturing with two kind of heat sources, i.e., cold metal transfer (CMT) and electron beam melting (EBM). The TiB2 particles were in nano-sized with some submicron-sized particle clusters , and their morphologies were round and near round without sharp angles. It was found that the introduce of TiB2 particles improved the mechanical properties of Al-5Cu alloy obviously. The results demonstrated that both the additive manufacturing methods of cold metal transfer (CMT) and electron beam melting (EBM) could improve the microstructure of the composites significantely. Compared with the traditional casting, Al-5Cu alloy the grain sizes of the TiB2 reinforced Al-5Cu composites decreased from larger than 100 μm to 40 μm with CMT process and 25 μm with EBM process. The hardness of the TiB2 reinforced Al-5Cu composites with EBM after heat treatment could be reached to 153 HV10. The refined grains and high hardness of the TiB2 reinforced Al-5Cu composites with EBM additive manufacturing technique verified that AM technology is a promising way to optimize the microstructure and mechanical properties of Al-Cu composites.