Ti_3Al金属间化合物氢致解理断裂及其机理

HYDROGEN INDUCED CLEAVAGE FRATURE IN Ti_3Al AND ITS MECHANISM

Ｔｉ－２４Ａｌ－１１Ｎｂ合金在室温下恒载荷动态充氢以及交变载荷动态充氢时，氢通过促进裂纹在滑移面上的解理，促进了裂纹扩展。不连续的氢致解理裂纹优先在α_２相形核，α_２／β相界面是裂纹扩展的有效障碍。氢通过促进裂尖位错的发射、解理微裂纹在无位错区（ＤＦＺ）的形核以及解理裂纹的扩展。

For Ti-24Al-11Nb alloy,the hydrogen induced crack (HIC) propagation was facilitated through the crack cleavage on the slip planes during dynamic hydrogen charging under either constant or alternating loading at room temperature. The discontinuous HIC was preferentially nucleated in a2-platelets. The α2/βboundaries are effective barriers to HIC nucleation and propagation. Hydrogen induces cleavage fracture by promoting the emission of dislocation at the crack tip as well as the nucleation and propagation of microcracks in the DFZ