Study on the ground surface quality of Cr2O3 coatings

The ground surface quality of Cr2O3 coatings is investigated in this paper. The influence of some typical grinding parameters on ground surface integrity is discussed in detail. It is found that the ground surface roughness increases with the increase of the depth of cut. The surface finish is improved with the increase of the grinding speed, but too high a grinding speed may result in serious vibration of the system. The increase of workpiece speed causes deterioration of the surface finish and produces loud grinding noise. Experiments on plateau treatment after the rough ground surface had been produced were also carried out. The surface profile of the ground surface after plateau treatment becomes much smoother than the former rough surface. Some sharp peaks on the ground surface may be effectively removed by the plateau treatment, which produces a reasonable surface profile that can withstand much more load. Surface observations and analyses show that plastic deformation and micro-cracks occur on the ground surface. The material removal process is primarily localized surface fractures accompanied by multi-plastic deformation. Much more plastic deformation and many micro-cracks emerge on the ground surface when the depth of cut increases. The increase of workpiece speed may produce more surface micro-cracks, but the relative increase of grinding speed is beneficial to ground surface quality.