Thermomechanical Fatigue of Single-Crystal Superalloys: Influence of Composition and Microstructure
2012 (English)In: Superalloys 2012: 12th International Symposium on Superalloys, The Minerals, Metals, and Materials Society, 2012, 369-377 p.Conference paper, Presentation (Refereed)
The thermomechanical fatigue (TMF) behaviour of a new high Cr-containing single crystal superalloy, known as STAL-15, is investigated. This is a candidate alloy for future industrial gas turbine (IGT) applications. TMF involves complex interactions between high and low temperature deformation mechanism, and this study highlights important factors controlling their interrelationship. Emphasis is placed particularly on the microslructural aspects which control deformation. It is demonstrated that the TMF performance of the new alloy is comparable to that of a second generation alloy such as CMSX-4, despite the absence of Re alloying. An addition of 0.25wt% Si significantly improves the resistance to TMF further; this is attributed to a greater resistance to recrystallization and cracking along the deformation bands that develops across the cross section of the specimen during testing. The TMF resistance increases with increasing primary γ′ size, but the degree of solutioning of the γ′ phase caused by the solution heat treatment seems to have no significant effect.
Place, publisher, year, edition, pages
The Minerals, Metals, and Materials Society, 2012. 369-377 p.
thermomechanical fatigue, single cyrstal superalloy, STAL-15
Engineering and Technology Materials Engineering
IdentifiersURN: urn:nbn:se:liu:diva-81531DOI: 10.1002/9781118516430.ch40ISBN: 9780470943205 (print)ISBN: 9781118516430 (online)OAI: oai:DiVA.org:liu-81531DiVA: diva2:553206
Superalloys 2012: 12th International Symposium on Superalloys, September 9-13 2012, Seven Springs, USA