Rene' N6: Third Generation Single Crystal Superalloy

Abstract

A new third generation single crystal superalloy has been developed for aircraft engine turbine airfoil applications.This alloy, Rene N6, is microstructurally stable and is approximately 30°C stronger than the second generation single crystal, RenC N.5. A new type of instability phenomena, SRZ, was encountered in the alloy development process.SRZ is a cellular precipitation reaction that primarily occurs beneath coatings, but can also be found along grain boundaries. RenC N6 was developed to avoid the detrimental SRZ, while maintaining excellent creep strength.The mechanical properties and environmental resistance of Rene N6 are covered and compared to similar superalloys.RenC N6 has undergone extensive engine testing and currently is being utilized for production engines.

Formation of an Intermediate Layer Between Grains in Nickel-Based Superalloy Turbine Blades

“…However, the distribution of alloying elements near Re-rich particles in this study is uniform. Most of all, from the DP reaction, needle-like TCP phases are formed and usually aligned perpendicular to the growth interface, [46] while in this study, round-shaped Re-rich particles were randomly distributed along the interface. In addition, the Re-rich particles exist inside the elongated c¢ as well as c phase in the intermediate layer, which means that it is difficult to explain this observation with the DP reaction and subsequent TCP precipitation as there is no previous observation showing these Re-rich particles which exist from the as-cast state.…”

MC-NG: A 4th Generation Single-Crystal Superalloy for Future Aeronautical Turbine Blades and Vanes

“…This layer also plays the role of bondcoat for the thermal barrier coating. However the protection can induce the formation of a Secondary Reaction Zone (SRZ) within the underlying material [3,4]. This zone contains plate-like shaped Topologically Closed Packed (TCP) precipitates which could affect the mechanical properties [5,6].…”

“…In the model we take into account: -the fatigue damage (Df) which is a function of the number of cycles, -the creep damage (D,J which is a mnction of the time. With: (4) The coefficients fl, a, 00, MO, bl and bz are unique for a given material. Q= % 0 r(l-Dc)-k& (5) The coefficients A, r and k depend on the alloy and the temperature.…”

Solute Redistribution during Planar and Dendritic Growth of Directionally Solidified Ni-Base Superalloy CMSX-10

“…The addition of these heavy refractory elements has conferred considerable solid solution strengthening with simultaneous increases in high temperature creep resistance. For this reason, the total amount of refractory alloying addition has been gradually increased in the advanced Ni-base superalloys [1,2]. However, the refractory elements segregate severely during solidification [3,4], which often lead to a number of problems such as (i) interdendritic porosity [5], (ii) misoriented grains [6], (iii) freckle formation [6,7], (iv) localized phase instability [8,9], and (v) formation of topologically close-packed (TCP) phases [9,10].…”