ENERGY-DISSIPATION DURING HIGH-TEMPERATURE DISPLACEMENT-SENSITIVE INDENTATION IN CUBIC ZIRCONIA SINGLE-CRYSTALS

A newly designed displacement-sensitive hardness tester capable of per forming load-displacement experiments in the temperature range 20 to 8 00 degrees C is described. Load-displacement indentation tests have be en performed in 9.4 and 21 mol% Y2O3 fully stabilized cubic ZrO2 singl e crystals. The effect of the alloying concentration oil the deformati on substructure in the vicinity of the indentation impressions was inv estigated using selective etching. The energy dissipated during the lo ading-unloading indentation cycle has: been measured and compared with the extent and structure of the deformation zone. The relative roles of the different energy dissipation mechanisms during indentation are discussed.