Ti65合金的初级蠕变和稳态蠕变

使用透射电镜(TEM)研究了Ti65合金在600~650℃、120~160 MPa条件下的蠕变变形行为及其微观变形机制。结果表明：初级蠕变变形机制主要由受攀移控制的位错越过α₂相的过程主导；稳态蠕变阶段蠕变机制主要由受界面处扩散控制的位错攀移的过程主导，且应力指数为5~7。在初级蠕变阶段α₂相与位错的相互作用是α₂相对合金高温强化的主要方式，在稳态蠕变阶段沿α/β相界分布的硅化物阻碍位错运动与限制晶界滑移是硅化物对合金强化的主要方式。

Primary Creep and Steady-State Creep of Ti65 Alloy

The creep deformation behavior and relevant microscopic deformation mechanisms of Ti65 alloy were investigated via tensile creep test by stresses in the range of 120~160 MPa at 600~650^oC and TEM observation. The results show that the primary creep deformation mechanism is dominated by the process of climbing-controlled dislocations crossing the α₂ phases and the creep mechanism in the steady-state creep stage is dominated by the process of diffusion-controlled dislocation climbing at the α/β interfaces, and the stress index of steady-state creep stage varies from 5 to 7. The hindering of dislocation motions by α₂ phases is the dominating process to strengthen the high-temperature creep resistance of Ti65 alloy during the primary creep stage. The silicide precipitates distributed along α/β phase boundaries, impede the dislocation motions and restrict the grain boundary slip (GBS), which is the dominating strengthening mechanism during the steady-state creep stage.