Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7880082 | Acta Materialia | 2015 | 12 Pages |
Abstract
The thermal-mechanical fatigue (TMF) behaviour of a new single crystal superalloy suitable for power generation applications is considered. Effects of alloying with either Si or Re are elucidated. Out-of-phase TMF is emphasised, although to clarify the effects arising some static creep deformation tests are also carried out. A significant Si-effect is found: a modest addition of 0.25 wt.% Si increases the TMF life by a factor of 2. A greater lower temperature yield stress and thinner slip bands traversing the γâ²-phase - with a concomitant greater resistance to recrystallisation and cracking along them - contribute to the enhanced TMF performance promoted by Si alloying. Alloying with Re, whilst improving the creep behaviour more markedly than Si, does not have such a strong effect on TMF life. The results provide insights into the composition/performance relationships relevant to the TMF performance of single crystal superalloys.
Related Topics
Physical Sciences and Engineering
Materials Science
Ceramics and Composites
Authors
Mikael Segersäll, Paraskevas Kontis, Stella Pedrazzini, Paul A.J. Bagot, Michael P. Moody, Johan J. Moverare, Roger C. Reed,