| Abstract: | Amorphous alumina coatings were deposited on high speed steel substrates by non reactive r.f. sputtering. The influence of the main deposition parameters on coating properties was studied, deposition conditions were selected in order to produce an amorphous, adherent, dense featureless coating for HSS oxidation prevention. Oxidation resistance tests were carried out in static air at 650°C and 800°C. At 650°C the coating prevents the oxidation of the substrates; at 800°C the coating presents cracking failure and the formation of a K-alumir.a phase occurs. |
