Since titanium has high affinity for hydrogen and reacts reversibly with hydrogen, the precipitation of titanium hydrides in titanium and its alloys cannot be ignored. Two most common hydride precipitates in α-Ti matrix are γ-hydride and δ-hydride, however their mechanisms for precipitation are still unclear. In the present study, we find that both γ-hydride and δ-hydride phases with different specific orientations were randomly precipitated in the as-received hot forged commercially pure Ti. In addition, a large amount of the titanium hydrides can be introduced into Ti matrix with selective precipitation by using electrochemical treatment. Cs-corrected scanning transmission electron microscopy is used to study the precipitation mechanisms of the two hydrides. It is revealed that the γ-hydride and δ-hydride precipitations are both formed through slip + shuffle mechanisms involving a unit of two layers of titanium atoms, but the difference is that the γ-hydride is formed by prismatic slip corresponding to hydrogen occupying the octahedral sites of α-Ti, while the δ-hydride is formed by basal slip corresponding to hydrogen occupying the tetrahedral sites of α-Ti.

由于钛对氢具有很高的亲和力，并且可与氢发生可逆反应，因此，钛及其合金中氢化钛的沉淀不容忽视。α-Ti基体中最常见的两种氢化物沉淀是γ-氢化物和δ-氢化物，但是它们的沉淀机理仍不清楚。在本研究中，我们发现具有不同特定取向的γ-氢化物相和δ-氢化物相均在收到的热锻造工业纯钛中随机沉淀。另外，通过使用电化学处理，可以选择性地将大量的氢化钛引入Ti基体中。用Cs校正的扫描透射电子显微镜研究两种氢化物的沉淀机理。