On the Microstructure of a Ni3Al/SiC/TiB2 Intermetallic Matrix Composite Processed by Spray Atomization and Co-Deposition

Abstract

AbstractThis work reports on the microstructure of a particulate reinforced nickel aluminide composite synthesized by spray atomization and co-deposition. This synthesis methodology involved using high energy inert gas to disintegrate the nickel aluminide matrix (IC-396) into a Gaussian distribution of micrometer-sized, semi-solid droplets while simultaneously co-injecting SiC and TiB2 particulates, followed by deposition onto a water cooled substrate. The microstructure of the as-spray deposited composite material consisted of a mixture of the ordered γ (Ni3Al) and the disordered γ (Ni-rich) phase with a homogeneous distribution of SiC and TiB2 particulates. Scanning electron microscopy, combined with Energy Dispersive X-ray Spectroscopy were used to provide insight into the reactions taking place in the interfacial zone. The results of the present study show that a well defined reaction zone was formed at the Ni3Al/TiB2 interface; whereas extensive reaction occurred between the SiC particulates and matrix, resulting in complete transformation of almost all SiC particulates into other carbide phases.