This work evaluated in depth the fatigue and fracture behavior of the metastable β Ti-15Mo alloy considering the presence of deformation twins and athermal nano-crystalline ω phase in the microstructure. Regardless of the microstructural condition studied, the as-received and the solution treated and quenched materials, ω phase remained unchanged, guaranteeing the static mechanical properties at acceptable levels. The mechanism of fatigue fracture was related to the existence of twins and maximum shear stress planes near the direction of screw dislocation motion in the BCC structure. The significant amount of deformation twins in the initial microstructure did not alter the fatigue limit, because the solution treated and quenched material unexpectedly developed twins during the fatigue test.

考虑到微观结构中存在孪生孪晶和无热纳米晶体ω相，这项工作深入评估了亚稳βTi-15Mo合金的疲劳和断裂行为。无论所研究的微观结构条件如何，按原样使用以及经过固溶处理和淬火的材料，ω相均保持不变，从而确保静态力学性能处于可接受的水平。疲劳断裂的机理与BCC结构中螺旋位错运动方向附近存在孪晶和最大剪切应力面有关。初始微观结构中大量的变形孪晶不会改变疲劳极限，因为在疲劳测试期间，经固溶处理和淬火的材料出乎意料地形成了孪晶。