Wetting and interfacial reactions in Al-Li-SiCp metal matrix composites processed by spray atomization and deposition

Abstract

The present study addresses the wetting and interfacial behaviour in a SiCp reinforced aluminium-lithium alloy processed by spray atomization and deposition. The microstructural characteristics of the spray atomized and deposited Al-Li-SiCp metal matrix composites were investigated as a function of processing history and thermal exposure. The present results show that there was sufficient interfacial activity at the Al-Li/SiC interface during deposition to establish a stable bond. Furthermore, the absence of interfacial reaction products suggests that the temperature during deposition remained relatively low. When the spray deposited material was exposed to temperatures in excess of 600 °C, severe interfacial reactions and the formation of oxide phases were noted. The microstructural studies were accomplished using optical microscopy, scanning electron microscopy (with energy dispersive X-ray spectroscopy), transmission electron microscopy, and X-ray diffractometry.