SELECTIVE STEAM OXIDATION OF TITANIUM AND ALUMINUM IN TIN AND (TI, AL)N PHYSICALLY VAPOR-DEPOSITED COATINGS ON DENTAL SURGICAL TOOLS

Sterilization of dental surgical tools such as drills and countersinks coated with hard nitride coatings for tool life improvement often involves exposure to steam in an autoclave. In order to investigate this wet-oxidation process of transition metal nitride coatings in more detail, magnetron sputter ion-plated TiN and (Ti, Al)N coatings on high speed steel (HSS) substrates were subjected to steam oxidation for various time periods. TiN deposited on HSS by electron beam physical vapour deposition was also steam oxidized for comparison. Auger electron spectroscopy combined with sputter depth profiling, secondary-ion mass spectroscopy and scanning electron microscopy were used to characterize the oxidized layer.