Ni-Al Intermetallic Compound Coating on 304 Austenitic Stainless Steel Using Combustion Synthesis

摘要

Ni-Al intermetallic compounds were coated onto AISI304 substrate surfaces using combustion synthesis. This paper examines the phase structure, Vickers hardness, and oxidation resistance of the coating layers. Ni-Al intermetallic compounds were confirmed to form for all of the specimens tested. With the highest composition tested, Ni- 75at percent Al, a diffusion layer from the bonding interface into the substrate was observed. The coating layer comprised multi-phases with a uniform distribution of fine pores resulting in a scatter of micro-Vickers hardness throughout the coating layer. A nearly single phase coating layer was obtained after heat treatment. The heat-treated layer was thus confirmed to exhibit further improvement in oxidation resistance than the coated layer before heat treatment.