High strength impact welding of 7075 Al to a SiC-reinforced aluminum metal matrix composite

Abstract

Abstract Vaporizing foil actuator welding (VFAW), an impact welding method, was used for the first time to produce high strength welds between SiC-reinforced 8009 aluminum metal matrix composite (MMC) (8009/SiC/11p) and 7075 aluminum alloy (AA7075). Microscopic characterization of the dissimilar impact weld revealed multiple heterogenous microstructural zones including an unbonded zone at the center, a flat interface, a wavy interface, and a trapped jet zone at the corner. SiC-depleted and SiC-rich bands were alternately distributed with consistent plastic flow patterns along the wavy interface. Microhardness tests prove that little or no heat or mechanically affected zones were formed in the dissimilar impact weld. Peel test yields a nugget pullout on the AA7075-T6 indicating high strength of the weld. VFAW process provides a solution to join the Al MMC with dissimilar metals in the applications of automotive and aerospace products.