The Effect of Volatilisation of Refractory Metal Oxides on the Cyclic Oxidation of Ni-base Superalloys

Abstract

The role of refractory metals on the bare oxidation behaviour of a range of compositionally complex single crystal Ni-base superalloys has been investigated using a range of techniques. It has been shown that this series of 4 th generation alloys were borderline alumina formers at 1100°C, and their cyclic oxidation performance was detrimentally affected by increased levels of Mo and Co. In addition, there was strong evidence that Re, Ru and Mo were lost through the process of cyclic oxidation, which supports the hypothesis that these elemental additions were lost through volatilisation/sublimation, contributing to their poor cyclic oxidation performance.

Influence of Titanium on the High Temperature Oxidation and Chromia Volatilization of Ternary Ni–Cr–C Alloys

“…Nickel-based alloys represent a particularly important class of superalloys for high temperature applications [1]. The most remarkable ones are the γ/γ' single crystals which offer very high levels of high temperature mechanical properties [2][3][4] and oxidation resistance [5][6][7][8]. Essentially devoted to constitute elongated pieces, these singlecrystal alloys are unfortunately not suitable to the compact geometries of many complex-shaped components for which other elaboration/shaping techniques must be preferred (conventional foundry, powder metallurgy…).…”