The measurement of surface contact fatigue and its application to engineering ceramics

摘要: Abstract Contact fatigue deformation and fracture in three zirconia ceramics has been induced by pressing 120° hardened silver steel conical tips against flat polished ceramic surfaces. The repeated point contact loading method that developed is described. It shown it possible for a softer material to induce cumulative plastic deformation, subsequent fracture, harder material. performance of single crystal cubic zirconia, tetragonal toughened partially stabilized have compared. In all cases, the ground cones plastically deformed during initial cycle produce flattened end which conformed with substrate. Cracking arising from damage under cyclic loads 19.6 ± 9.8 N was observed occur (001) calcia much earlier than appeared (111) plane. both formation progression ‘perimeter’ crack visible at edge zones as number cycles increased. proposed cracking initiated dislocation interaction mechanism. propagation primarily conchoidal form, rather crystallographically oriented. A monoclinic martensitic transformation occurred ceria beneath adjacent zone. zone increased size volume expansion associated this transition caused granular lifting, first around periphery contacting areas, then intergranular fragmentation, followed spalling mechanism magnesia combination two above, resulting transgranular fracture. No transfer, i.e. metal onto ceramic, or vice versa, generally until after had become well extended fragmented.