Abstract

Thin alumina films, deposited at 280°C on several high alloy steels by low-pressure metal-organic chemical vapor deposition (LP-MOCVD), were annealed at 0.17 kPa in a nitrogen atmosphere for 2, 4, and 17 h at 600 and 800°C. Film adhesion was studied by scanning scratch testing (SST) and Auger electron spectroscopy (AES). The best adhesion properties were obtained with commercial oxide dispersion-strengthened (ODS) high-temperature alloys, especially PM 3030. Among the 'normally' high alloy stainless steels, type AISI-321 showed the best adhesion. The other stainless steel-alumina combinations exhibited a reduced critical load, Lc, after thermal treatment. Alumina on ODS alloys exhibited an increased adhesion. AES studies revealed that this increase could be explained by: (1) the presence of sulfur-trapping elements, preventing segregation of sulfur at the interface; and (2) titanium and carbon enrichment at the interface, resulting in an anchoring effect between the oxide and the substrate.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call