Crack Propagation in Zirconia MgO-PSZ Ceramic Material
The properties of ceramic materials such as elevated hardness, high temperature capability, low coefficient of thermal expansion are of interest for rolling element materials. Widely used ceramic materials in engineering applications are silicon nitride, zirconia and alumina. The paper presents an experimental study of the fatigue life of MgO-PSZ ceramic material in lubricated contact with defined types of cracks. A ceramic angular contact bearing operation was simulated using a four-ball machine. Zirconia balls were artificially damaged with pre-cracks. Ringformed pre-cracks were propagated on the ball surface by a blunt impact load using a tungsten carbide ball under five various impacts. Research of the presented paper shows that fatigue failure under rolling contact loading is markedly sensitive on ringformed pre-cracks made by a different impact energy (drop height). Propagation of surface pre-cracks takes place under a fatigue load. Primary and secondary surface crack propagations are described.
W. Karaszewski "Crack Propagation in Zirconia MgO-PSZ Ceramic Material", Key Engineering Materials, Vol. 490, pp. 54-63, 2012