Enhanced mechanical properties in terms of strain hardening capacity and uniform strain have been measured for recently developed TRIP-TWIP $\beta -$metastable Ti alloys. However, hardly anything has been reported about their fracture properties. An original fracture scenario including adiabatic shear banding is proposed for both flat and cylindrical tensile specimens of Ti-12wt.% Mo tested in quasi-static conditions at room temperature. The geometry of the tensile specimens has a strong influence on the fracture mechanism. The fusible coating method was used with Sn and Cu coatings to qualitatively evaluate the evolution of the temperature during fracture, colder than 232°C during crack initiation and increasing up to the melting temperature of the alloy during crack propagation. High-speed imaging was also used to estimate the evolution of the crack propagation speed, increasing up to 1,840 $\mathrm{m}.{\mathrm{s}}^{-1}$, a level corresponding to unstable crack propagation. The evolution of the temperature rise and of the crack speed is linked to the specific fracture patterns.

已针对最近开发的 TRIP-TWIP 测量了在应变硬化能力和均匀应变方面增强的机械性能 $\beta -$亚稳态钛合金。然而，几乎没有关于它们的断裂特性的报道。对于在室温准静态条件下测试的 Ti-12wt.% Mo 的扁平和圆柱形拉伸试样，提出了包括绝热剪切带的原始断裂场景。拉伸试样的几何形状对断裂机制有很大影响。可熔涂层方法与 Sn 和 Cu 涂层一起用于定性评估断裂过程中温度的演变，裂纹萌生过程中温度低于 232°C，裂纹扩展过程中升高到合金的熔化温度。高速成像还用于估计裂纹扩展速度的演变，增加到 1,840$\mathrm{米}.{\mathrm{秒}}^{-1}$，对应于不稳定裂纹扩展的水平。温升和裂纹速度的演变与特定的断裂模式有关。