Crystallography and microstructure of the deformation bands formed in a metastable β titanium alloy during isothermal compression

The plastic deformation of crystals accompanied by the formation of deformation bands or slip bands has been observed in previous studies; however, this phenomenon has not been examined in sufficient detail. In this study, the crystallography and microstructure of the deformation bands formed in a metastable beta titanium alloy Ti-7Mo-3Nb-3Cr-3Al during isothermal compression were investigated. The obtained results revealed that numerous deformation bands were formed inside the beta grains and along the initial beta grain boundaries. The majority of the produced bands were located in the grain interiors, and their formation was accompanied by the fragmentation and spheroidisation of the lamellar alpha phase. According to the trace analysis results, these bands belonged to the {110} 111 slip band type and exhibited high Schmid factors. The crystallographic calculation data indicated that the rotation axis of the misorientation between the beta phase in the lamellar area and that in the band area passed through the deformation bands. Furthermore, the origin of the formation of bands was caused by the relative slip of the lamellar beta and alpha phases due to the coordinated shear under compression. Thus, the findings of this study can help achieve a better understanding of the hot deformation mechanisms of titanium alloys.

Automated summary

This study investigated the crystallography and microstructure of deformation bands formed in a metastable beta titanium alloy during isothermal compression. The majority of the bands were located inside the beta grains and along the grain boundaries, belonging to the {110} 111 slip band type with high Schmid factors. The formation of bands was found to be caused by relative slip of lamellar beta and alpha phases under compression.