Influence of elevated Co and Ti levels on polycrystalline powder processed Ni-base superalloy

Autor: KA Christofidou, J. P. Minshull, Howard J. Stone, Mark Hardy, P. M. Mignanelli, Nick Jones
Rok vydání: 2014
Předmět:
Zdroj: Materials Science and Technology. 30:1853-1861
ISSN: 1743-2847
0267-0836
Popis: The influences of elevated Co and Ti levels on the mechanical properties of the Ni-base superalloy RR1000 have been investigated. Following heat treatment, the modified alloys had the typical γ–γ′ microstructure, with γ′ precipitate sizes comparable to similarly heat treated RR1000, but with a slightly higher volume fraction. The modified alloys exhibited a higher proof stress than RR1000 across the entire 20 to 800°C temperature range investigated. Superior creep rupture lives, when compared to RR1000, were observed in the modified alloys at 700°C, but not at 750°C, where extensive precipitation of topologically close packed σ phase occurred on the grain surfaces. The formation of this deleterious phase was linked to Cr and Mo enrichment of the γ matrix, caused by the elevated Co and Ti additions.
Databáze: OpenAIRE
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