Microhardness measurements were carried out on ion implanted single crystal Y2O3 stabilized cubic ZrO2. Ions were implanted up to fluences of 3×1017 ions/cm2. Comparison of the Knoop micro-hardness values of ZrO2 implanted with various species over a range of fluences showed that the principle variable causing hardness changes for inert ion implantation is damage energy and not the ion fluence nor the ion species. For shallow inert ion implants, the hardness versus damage energy gives a unified plot. Hardnesses rise with increasing deposited damage energy to a value 15% higher than that of unimplanted zirconia. With additional damage the hardness drops to a value 15% lower than that of the unimplanted zirconia. Deep implants showed 50% increases in hardness and significant fracture toughness increases.
Friction and wear measurements of the shallow implants in a pin-on-disk assembly showed very different behavior for high dose versus unimplanted ZrO2. The unimplanted samples showed debris with an associated rise in friction. The implanted system showed much less debris and a constant value of friction even after 10,000 cycles.