Tension-compression asymmetry in yielding and strain hardening behavior of CP-Ti at room temperature

An Experimental Study of the Tension-Compression Asymmetry of Extruded Ti-6.5Al-2Zr-1Mo-1V under Quasi-Static Conditions at High Temperature

“…As the strain rate increases from 0.0001 to 0.005 s −1 , the yield stress rises from 150 to 368 MPa. According to Figure 7b,d, the θ changes little both in tensile and compressive deformation, and there is no three-stage hardening phenomenon [9] in (θ-ε) curves at 973 K. 7b,d, the θ changes little both in tensile and compressive deformation, and there is no three-stage hardening phenomenon [9] in (θ-ε) curves at 973 K.…”

“…where ε c is the dynamic recrystallization critical strain at 923-1023 K, ε takes the average strain value 0.2, 0.3 and 0.4 in tension and takes 0.7 in compression tests, respectively. The calculated results were compared with the results obtained from the microscopic observation [9] to verify the validity of the JMA parameters. Additionally, on this basis, the X dRX of compression test under small strain was calculated by using the JMA equation, and the result was compared with that of tensile test, as shown in Figure 11.…”

“…Additionally, on this basis, the X dRX of compression test under small strain was calculated by using the JMA equation, and the result was compared with that of tensile test, as shown in Figure 11. The calculated results were compared with the results obtained from the microscopic observation [9] to verify the validity of the JMA parameters. Additionally, on this basis, the of compression test under small strain was calculated by using the JMA equation, and the result was compared with that of tensile test, as shown in Figure 11.…”

“…Akhtar et al [14] ha on three Ti-6Al-4V materials at 233-755 K with strain rates supported that the yield stress and strain hardening of th Many scholars have found that there is TCA in pure titanium and its alloys at room temperature and medium-high temperatures (≤873 K). Lin et al [9] studied the TCA of pure titanium (CP-Ti) at room temperature and stated that the difference of the stress values activating the secondary twins is the main cause of TCA at room temperature. Tuninetti et al [10] investigated the mechanical response of Ti-6Al-4V based on the target strain rate and the results indicated there is obvious TCA at ambient temperature.…”

Characterization and Modeling of Room-Temperature Compressive Creep Behavior of a Near α TA31 Titanium Alloy

“…By comparing with the published data, it can be concluded that the threshold stress for room temperature creep in the present study is higher than that in the published literature, which may be caused by the two different loading methods of compression and tension. Although the deformation mechanisms of tension and compression are both dislocation slip and twinning, there is anisotropy in tension and compression of titanium alloys [18,19]. Roberts et al [20] found significant tension-compression asymmetry for <c + a> pyramidal slip in Ti-6Al alloy, and the critical resolved shear stress increase to 820 MPa under compression and decrease to 558 MPa in As the stress increasing and higher than a threshold stress, the creep strain apparently increases with creep time and significant creep appears.…”