Impact of microstructure, temperature and strain ratio on energy-based low-cycle fatigue life prediction models for TiAl alloys

In this paper, two fatigue lifetime prediction models are tested on TiAl intermetallic using results from uniaxial low-cycle fatigue tests. Both assessments are based on dissipated energy but one of them considers a hydrostatic pressure correction. This work allows to confirm, on this kind of material, the linear nature, already noticed on silicon molybdenum cast iron, TiNi shape memory alloy and 304 L stainless steel, of dissipated energy, corrected or not with hydrostatic pressure, according to the number of cycles to failure. This study also highlights that, firstly, the dissipated energy model is here more adequate to estimate low-cycle fatigue life and that, secondly, intrinsic parameters like microstructure as well as extrinsic parameters like temperature or strain ratio have an impact on prediction results.