Grinding of nanostructural ceramic coatings: damage evaluation

This paper investigates the damage, mainly surface and subsurface cracks, in ground n-Al2O3/13TiO2 and n-WC/12Co coatings. Surface cracks are formed under some special conditions. The presence and formation of the surface cracks are studied.Subsurface damage, especially cracks, of the ground components greatly influences their performance and life in service. The effects of the grinding conditions such as material removal rate, wheel grit size and bond materials on the subsurface damage, especially subsurface cracks, are investigated. The difference of material properties of these two coatings also influences the subsurface cracks. Different from bulk samples, large quantities of defects inherited from the thermal spray process play a significant role in the initiation and development of the cracks, present the crack configurations more complex than the typically reported system of median and lateral cracks observed in ground bulk ceramics. This complexity is analyzed. [Copyright &y& Elsevier]