A Pt-modified Ni-base superalloy with high temperature precipitate stability

Nickel-base alloys display exceptional mechanical properties to high fractions of their melting point due to the presence of L12 γ′ precipitates. However, above 1000 °C, the precipitates typically coarsen or rapidly undergo shape changes along with dissolution into the matrix, thereby degrading the mechanical performance of the alloy at higher temperatures. In this research, a Pt-modified Ni-base alloy with exceptional high temperature stability has been identified. Coarsening studies conducted in the temperature range from 1050-1200 °C reveal unusually high volume fractions of morphologically stable γ´ precipitates up to 1200 °C. Electron-probe micro-analysis demonstrates strong partitioning of Pt to the γ´ phase. The presence of a high volume fraction of slowly coarsening precipitates at 1200 °C suggests that the alloy would have excellent performance as a bond coat and/or single crystal blade.