CRACK NUCLEATION AND PROPAGATION IN HYDROGENATED POLYCRYSTALLINE α-Ti
YIN Wanquan;SU Huihe;XU Yongbo;QIN Rongshi;LIU Minzhi Institute of Metal Research;Academia Sinica;Shenyang
Cite this article:
YIN Wanquan;SU Huihe;XU Yongbo;QIN Rongshi;LIU Minzhi Institute of Metal Research;Academia Sinica;Shenyang. CRACK NUCLEATION AND PROPAGATION IN HYDROGENATED POLYCRYSTALLINE α-Ti. Acta Metall Sin, 1985, 21(4): 63-152.
Abstract The hydrogenated polycrystalline α-Ti was in situ observed under SEM toobtain a better understanding of its tensile fracture microprocess,principally,ofthe correlation of contents between overall H_2 and hydride,of the effect of hy-dride on the crack nucleation and propagation,as well as of the behaviour ofthe deformation and fracture microprocess caused by hydride.It was found that:(1)The crack nucleation in the polycrystalline α-Ti with H_2 content less than152 ppm is irrelevant in the hydride.It is ductile cracking and conforms to theslip mechanism.While its H_2 content more than 727 ppm,it is brittle cracking,controlled by the hydride and belongs to the nonslip mechanism;(2)In α-Ti withlower H_2 content,the transgranular crack propagation along a zigzag pathforward is controlled by maximum shear stress.On the contrary,in α-Ti withhigher H_2 content,the crack is intergranularly propagated still along a zigzagpath forward,yet lost its ductile feature.
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