Isothermal and thermomechanical fatigue behaviour of Ti-6Al-4V titanium alloy

In this study, the overall view of in-house development of thermomechanical fatigue (TMF) test capability has been presented. Using this test facility, mechanical strain controlled in-phase (IP) and out-of-phase (OP) TMF behaviour of Ti-6Al-4V alloy has been investigated in the temperature range 100-400 degrees C with ramp heating and cooling rate of 2 degrees C/s. Isothermal low cycle fatigue (IF) tests have also been conducted at 100 degrees C and 400 degrees C for comparison with TMF data. The combined effect of development of tensile mean stresses and metallurgical degradation due to oxidation led to detrimental OP-TMF fatigue life as compared to IP-TMF and IF loading. (C) 2011 Elsevier B.V. All rights reserved.