THE DEVELOPMENT AND APPLICATION OF CMSX®-10

G. L. Erickson

Cannon-Muskegon Corporation
[SPS Technologies]

Muskegon, MI  U.S.A.

ABSTRACT

The CMSX®-10 alloy is a third generation single crystal (SX) casting material which is used in demanding turbine engine blading applications. The flight engine certified alloy is characterized by it's 6 wt. % rhenium content, high additive refractory element level, and relatively low chromium employment. Based on published data, the alloy is thought to exhibit the highest creep strength and resistance to fatigue of any production Ni-base, cast SX superalloy.

CMSX-10 alloy provides an approximate 30°C improved creep strength relative to second generation 3 wt. % containing SX alloys such as CMSX-4 and PWA 1484. Furthermore, it develops low cycle and high cycle fatigue (LCF and HCF) strengths as much as 2-3 times better than the best alternatives. Moreover, the alloy also develops an attractive blend of tensile and impact strengths, foundry performance, heat treatability and environmental properties characteristic. Most notably, the alloy provides surprisingly good hot corrosion resistance, despite its novel and relatively low chromium content (2-3 wt. %). Additionally, the alloy performs extremely well in both the aluminide and Pt - aluminide coated conditions.

Although the CMSX-10 alloy was developed to fulfill a perceived need in the aero-turbine industry, the alloy's long-term high strength, particularly at temperatures ranging from 850-950°C, has attracted significant industrial turbine interest. For this reason, longer term (currently to about 5000 hours) creep-rupture strength characterization is underway. Similarly, due to a continued need for materials with greater creep-strength, a higher strength CMSX-10 derivative, currently designated CMSX-10+, is under development.

This narrative characterizes the CMSX-10 alloy SX component castability, heat treatability, mechanical strength, environmental properties and coating characteristics. Active long-term creep-rupture programs are discussed, as well as preliminary results for a higher strength alloy, currently designated CMSX®-10+.