Method of surface alloying sialon articles
AssigneeKennametal Inc.
InventorsPankaj K. Mehrotra, Joyce L. Swiokla
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Abstract
A method of surface alloying a sialon article containing beta-prime-sialon phase (Si.sub.6-z Al.sub.z O.sub.z N.sub.8-z). The method includes the steps of applying an alumina coating to the surface of the sialon article by chemical vapor deposition and then heat treating the coated article at a temperature between about 1300 and 1800 degrees Centigrade for a time sufficient to diffuse some or all of the aluminum and oxygen from the alumina coating into the sialon composition to produce a layer containing beta-prime-sialon phase having an increased Z value compared to the beta-prime-sialon phase in the remainder of the article.
Claims24
A method of alloying the surface of a sialon article consisting essentially of beta-prime-sialon phase to increase the Z value of the beta-prime-sialon phase near the surface, said method comprising the steps of:
- (a) preparing a sialon article,
- (b) applying an approximately 1 to 10 micron thick coating of alumina to the surface of the sialon article by chemical vapor deposition, and
- (c) heat treating the coated sialon article at a temperature between about 1300 to 1800 degrees Centigrade to diffuse oxygen and aluminum of the alumina coating into the surface of the sialon article to produce a diffusion zone containing beta-prime-sialon with an increased Z value compared to beta-prime-sialon phase in the remainder of the sialon article.
Dependencies are inferred from the claim text.