Determination of Ti-6242 alpha and beta slip properties using micro-pillar test and computational crystal plasticity

作者：Zhang Zhen; Jun Tea Sung; Britton T Benjamin; Dunne Fionn P E

来源：Journal of the Mechanics and Physics of Solids, 2016, 95: 393-410.

DOI：10.1016/j.jmps.2016.06.007

• beta beta
• phase
• Ti-6242
• Micro-compression
• Stress relaxation
• Strain rate sensitivity
• Slip transfer
• Burgers orientation relationship

The properties and behaviour of alpha-beta colony Ti-6242 alloy have been investigated at 20 degrees C utilising coupled micro-pillar stress relaxation tests and computational crystal plasticity. The beta-phase slip strength and intrinsic slip system strain rate sensitivity have been determined, and the beta-phase shown to have stronger rate sensitivity than that for the alpha phase. Close agreement of experimental observations and crystal plasticity predictions of micro-pillar elastic-plastic response, stress relaxation, slip activation in both alpha and beta-phases, and strain localisation within the alpha-beta pillars with differing test strain rate, beta morphology, and crystal orientations is achieved, supporting the validity of the properties extracted. The beta-lath thickness is found to affect slip transfer across the alpha-beta-alpha colony, but not to significantly change the nature of the slip localisation when compared to pure alpha-phase pillars with the same crystallographic orientation. These results are considered in relation to rate-dependent deformation, such as dwell fatigue, in complex multiphase titanium alloys.

• 出版日期2016-10