AlN and intermetallic compound layers formed between aluminum and austenitic stainless steel using barrel nitriding

Recently, a new nitriding process was proposed to produce the aluminum nitride on an aluminum surface using a barrel. After barrel nitriding, AlN nitride layer is formed on the aluminum surface and the surface hardness can be improved remarkably. In this study, barrel nitriding was performed to investigate the interface between aluminum substrate, with SUS304 austenitic stainless steel used for a physical catalyst. The barrel nitriding was carried out at 893 K for 18 ks, 25.2 ks and 36 ks, respectively with aluminum and aluminum–magnesium alloy powder. After barrel nitriding, aluminum nitride layer and Fe–Al intermetallic compound layers were formed at the interface between pure aluminum and austenitic stainless steel at the same time. The thickness of the aluminum nitride layer and intermetallic layer was increased by increasing the treatment time.