Structural behaviour of sputtered W-C-Co coatings at increasing temperatures

✍ Scribed by A. Cavaleiro; M. T. Vieira

• Book ID: 104741519
• Publisher: Springer
• Year: 1993
• Tongue: English
• Weight: 586 KB
• Volume: 28
• Category: Article
• ISSN: 0022-2461
• DOI: 10.1007/bf00365028

✦ Synopsis

In order to evaluate the thermal resistance of sputtered W-C-Co coatings, a structural study was carried out on amorphous and crystalline coatings according to their cobalt content after having been annealed at increasing temperatures up to 800~ All the films were stable up to 700~ at which temperature the amorphous films began to crystallize as cz-W2C; for higher temperatures the r carbide evolves to M6C, the extent of which increases the higher the cobalt content; for low cobalt content films WC carbide was also formed. Crystalline films have similar structural transformations, although the M6C phase is almost non-existent and r W2C and WCcan Occur with preferential orientations. In all cases, the films after annealing were carbon-deficient in relation to the results obtained for the as-deposited conditions; in spite of the fact that the phases detected after crystallization are also carbon-deficient, these results are not consistent which implies that some free carbon should exist in the annealed films.