Wear properties of yttria-stabilized hafnia overcoats (abstract)

Yttria-stabilized hafnia is shown to be another transformation toughening ceramic with good tribological properties. The hafnia was rf-diode sputtered over a 300 nm chromium underlayer on textured aluminum-NiP 130 mm diameter substrates. Wear properties of the hafnia overcoat were evaluated, via contact start-stop (css) testing, as a function of oxygen partial pressure, substrate bias potential and argon pressure. Depending on deposition conditions, a wide range of wear properties were observed. Lower oxygen partial pressures