Superalloy eutectic composites with the VI A refractory elements - Cr, Mo and W

Abstract

The paper discusses the phase equilibria for the ternary systems NiAlCr, NiAlMo, and NiAlW, with emphasis on reactions from the liquid state, although some of the solid state reactions are mentioned. It is shown that eutectics in the Ni-Al-refractory element (Cr, Mo, W) systems offer the potential for high-temperature turbine blade and vane applications. In particular, it is shown that the phase diagrams of these ternary systems can be manipulated to alter the eutectic phases and morphologies by simple quaternary alloying modifications. The resultant combination of chemistry and structure can be controlled to ensure a behavior that is well-matched to hot section component materials requirements.