Development of a new fatigue and creep resistant PM nickel-base superalloy for disk applications

Abstract

Recent analysis of requirements and limitations in both economics and environmental issues of the development of modern turbine engines has led to redefine the specifications to be filled by superalloys for disk applications. Various criteria derived from these specifications helped to formulate a number of original alloy chemistries. These alloys were produced using powder metallurgy route at laboratory scale for microstructural and mechanical data collection. Two alloys were then selected for production by industrial processes and patented as SMO43 and SMO48. After thermomechanical treatments, the microstructural features and the mechanical properties of these two alloys were thoroughly evaluated. Tensile strength, LCF and FCG behaviours prove to be at least as good as N18's and creep strengths significantly higher. Finally, SMO43 appears to better fulfil the selection criteria.