Experimental comparison of ground surface characteristics for P/M Ti2AlNb-based alloy using CBN and diamond grinding wheels

Abstract

An experimental comparison of ground surface characteristics for P/M Ti2AlNb-based alloy using CBN and diamond grinding wheels was conducted. The effects of the grinding depth and grinding wheel type on the ground surface roughness, microhardness, and microstructure were investigated. The surface roughness resulted from the CBN wheel was about 1.4–1.6 times rougher than that resulted from the diamond wheel. With the increase of grinding depth, the subsurface microhardness decreased and the thickness of the softened layer increased. This trend emerged more strongly in using diamond wheel. When the grinding depth was 0.03 mm, the surface material suffered recrystallization in which O-phase and α2-phase transformed into B2-phase by high local temperature of the grinding zone. In the case of the diamond wheel, chemical wear occurred by the chemical reaction between the carbon from grits and the titanium of the grinding material. The chemical wear of the diamond wheel is a main reason of the quality difference between the ground surfaces using the CBN and diamond wheels.