2011 Volume 52 Issue 8 Pages 1595-1602
The effects of restricted slip conditions on both the Taylor factor and plastic work rate under the condition of tensile yielding have been analyzed in α-titanium alloys at low temperatures, using the full constraints model. The role of secondary slip systems, i.e., the 〈a〉 basal slip and 〈c+a〉 pyramidal slip, was clarified, when the 〈a〉 prismatic slip was dominant. Although no influence of secondary slip conditions on the Taylor factor was detected, the plastic work rate was sensitive to the operating secondary slip systems. When the basal system was chosen as the secondary slip system, the plastic work rate increased in all tensile axes, especially around 〈0001〉. In addition, no basal slip operation decreased the plastic strain energy. The plastic work rate was the highest along the 〈0001〉 tensile axis, and the operation of the 〈c+a〉 pyramidal slip was necessary to achieve plastic deformation along c axis. High elastic strain energy, therefore, must accumulate to a high level around 〈0001〉, because the pyramidal slip is hardly active owing to its very high critical resolved shear stress.