Effect of Strain on Compression Mechanism of Ti-55531 Alloy at Room Temperature

Based on metastable 3 titanium alloy Ti-55531, the structure of the sample was obtained by solution quenching above the beta phase. Room temperature compression was performed using a Gleeble3800 thermal simulation test machine and a 6.3 MN forging simulator. OM, XRD and TEM were used to observe the deformed structures after different strains. The results show that the maximum compression of 30% room temperature true-stress and true-strain curve at the strain rate of 0.0005 s(-1) is mainly divided into two stages that are elastic deformation stage and plastic deformation stage with obvious strain hardening stage. However, the maximum compression of 30% room temperature true-stress and true-strain curve at the strain rate of 0.1 s(-1) is mainly divided into two stages that are elastic deformation stage and plastic deformation stage with flow softening instead of obvious strain hardening. Both of them do not have double yield phenomenon. The deformation structures have few differences at different strain rates of the same reduction. The deformation mechanism is dominated by slip. With the strain increasing, the dislocation density increases gradually and the dislocation tangles and shears appear. Strain induced martensite transformation occurs at the compression of 30% and the strain rate of 0.0005 and 0.1 s(-1). Strain induced martensite transformation is also found at the strain rate of 10 s(-1) when the compression is 50% and 60%.