Characterisation of rare earth assisted plasma carbonitrided TiNi alloys

Abstract

In order to increase the thickness of diffusion layers on TiNi alloys, the rare earth (RE) metals La and Ce were employed in the plasma carbonitriding process. The phases, microstructures and wear behaviours of the coated TiNi with and without RE assistance were compared. Experimental results indicated the addition of RE obviously increased the thickness of diffusion layer from 2·5 to 12·5 μm. Rare earth assisted plasma carbonitrided samples had less weight loss, and thus they exhibited better wear resistance than specimens plasma carbonitrided without RE assistance.