Pore-induced defects during thermo-mechanical fatigue of a fourth-generation single crystal superalloy

Joint Development of a Fourth Generation Single Crystal Superalloy

A new, fourth generation, single crystal superalloy has been jointly developed by GE Aircraft Engines, Pratt & Whitney and NASA. The focus of the effort was to develop a turbine airfoil alloy with long-term durability for use in the High Speed Civil Transport. In order to achieve adequate long-time strength improvements at moderate temperatures and retain good microstructural stability, it was ...

Fatigue crack initiation in a notched single-crystal superalloy component

In this paper, the fatigue crack initiation in notched single-crystal test specimens of material MD2 is investigated and analysed. A critical plane approach is adopted, in which the total strain ranges on the discrete slip planes are evaluated. Furthermore, a Coffin-Manson type of expression is used to describe the number of cycles to fatigue crack initiation. This relation is determined from a...

An Empirical Approach to Correlating Thermo-Mechanical Fatigue Behaviour of a Polycrystalline Ni-Base Superalloy

Assessment of thermo-mechanical fatigue behaviour of the polycrystalline nickel alloy RR1000 reveals a significant effect of phase angle on fatigue life. The current paper explores two scenarios: the first where the mechanical strain range is held constant and comparisons of the fatigue life are made for different phase angle tests; and secondly, the difference between the behaviour of In-phase...

Effects of Specimen Geometry and Coating on the Thermo-mechanical Fatigue of Pwa 1484 Superalloy

Influence of crystal orientation on the thermomechanical fatigue behaviour in a single- crystal superalloy