Thermo-mechanical fatigue of a coated and uncoated nickel-based alloy
Out-of-phase thermo-mechanical fatigue (TMF) tests were performed on a coated and bare nickel-based alloy. Initial findings indicate that the nickel aluminide coating reduces the TMF life of the high temperature alloy for applied mechanical strain ranges below 0.80%; for strain ranges in excess of this maximum value, the coating has little to no effect on the fatigue resistance of the material. This result is a consequence of the differing modes of deformation which are active above and below this critical value. Specifically, for mechanical strain ranges above 0.80% the mode of deformation is heterogeneous, whereby the TMF life is controlled by slip along glide planes and the cutting of the gamma' phase. For applied strain ranges below 0.80% the alloy deforms homogeneously. Dislocations are not limited to glide planes, no cutting of gamma' is evident and fracture typically occurs in a direction perpendicular to the stress axis. In addition, Manson-Coffin stress data reveal the existence of a fatigue limit at approximately 550 MPa.
Bibliographic Reference: Paper presented: International Conference on Mechanical Behaviour of Materials ICM-6, Kyoto (JP), July 29 - August 2, 1991
Availability: Available from (1) as Paper EN 35951 ORA
Record Number: 199110366 / Last updated on: 1994-12-02
Original language: en
Available languages: en