Damage accumulation caused by cyclic indentation in zirconia ceramics

Indentation fatigue testing is carried out for four kinds of zirconia ceramics; 6Y-FSZ, 3Y-TZP, Mg-PSZ and Ce-TZP; which have different strengthening-toughening mechanisms one another. Each material shows different indentation fatigue behavior. Large sized surface chipping is produced easily in early cycles for non-toughened 6Y-FSZ, while 3Y-TZP toughened by anelasticity has high resistance against chipping. There is a possibility that anelastic characteristic works as resistance against indentation fatigue damage. Stress induced phase transformation also improves fatigue damage, but this effect depends on the extent of transformation and/or occurrence of microcracking. (C) 1999 Kluwer Academic Publishers.