|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Gamma (FCC)/Gamma-Prime (L12) Co-Based Superalloys II
||Coating Systems for New Cobalt Base Single Crystals
||Wesley Jackson, Mike Titus, Tresa Pollock, Matt Begley
|On-Site Speaker (Planned)
New cobalt-base alloys containing L12 strengthening precipitates show promise in their single crystal form for high temperature turbine applications. As with Ni-base alloys, it is expected that multilayered coating systems compatible with the single crystal substrate will be required for thermal and environmental protection. Elevated temperature structure evolution in MCrAlY bond coatings applied to Co-base single crystals has been investigated. To assess the compatibility of MCrAlY + 7YSZ thermal barrier coatings, the thermal expansion behavior of the Co-base single crystals has been characterized. Stresses and energy release rates driving interfacial cracking have been analyzed in comparison to Ni-base systems. The driving force for coating failure is sensitive to the composition of the Co-base alloy. Strategies for reducing the driving forces for delamination will be discussed.