Temperature- and Mo-content dependent deformation mechanisms of β-Ti-Mo alloy under dynamic compression

Two representative β -Ti–Mo alloys, Ti–15Mo and Ti–32Mo, are dynamically compressed to a strain of 10% at temperatures ranging from 123 K to 673 K to investigate the plastic mechanisms and resulting deformation texture. Electron backscatter diffraction data are collected from postmortem samples and quantitatively processed to analyze deformation twins and geometrically necessary dislocations (GNDs). Transmission electron microscopy further validates the thin deformation twin and dislocation configurations. Both alloys exhibit high yield strength (690–1100 MPa for Ti–15Mo and 930–1720 MPa for Ti–32Mo) but limited strain hardening under dynamic loading. Increasing Mo content enhances significantly the yield strength and its sensitivity to temperature, but concurrently reducing the strain hardening rate. The dominant deformation mode shifts with increasing Mo concentration: { 332 } 〈 113 〉 twinning prevails in Ti–15Mo, whereas { 112 } 〈 111 〉 twinning dominates in Ti–32Mo at low temperatures (123–298 K). Both twinning modes are suppressed at 673 K. { 112 } 〈 111 〉 twinning in Ti–32Mo exhibits stronger Schmid factor dependence than { 332 } 〈 113 〉 twinning in Ti–15Mo. The GND density in all cases is well described by a lognormal distribution and increases markedly with increasing temperature. The resulting deformation texture is weak at low temperatures but evolves into a 〈 111 〉 fiber type in Ti–15Mo, and a dual 〈 111 〉 + 〈 100 〉 fiber texture in Ti–32Mo at higher temperatures.