Grinding of WC-Co hard-metals

Morphol. of ground surface of WC-Co cermets with 10 and 20% Co was studied. A deformed and detached surface layer was found on top of the specimens after surface grinding with a diamond wheel. Etching the surface layer revealed WC grains in the subsurface of the machined specimens. Most of these grains were plastically deformed by prismatic slip in the hexagonal lattice of WC. Cracks were also found in these grains. The increase in residual stress due to the grinding process was examd. by x-ray diffractometry. The stress increases to a max. value in the carbide grains before the relaxation occurs by slip and cracking. The surface roughness after grinding was measured by scanning confocal microscopy. Roughness exponents were calcd. from 3D profiles, and the values from this process were in good agreement with the values for grinding ceramics. [on SciFinder (R)]