钛中氘致裂纹的原位研究

In-situ Investigation on Deuterium Induced Cracking of Titanium

采用热台显微镜(HSM)和压力-体积-温度(PVT)相结合的方法原位研究了钛在恒定温度及升温过程中的氘致裂纹(DIC)现象。结果表明:在550℃恒温吸氘(D2)过程中,钛片表面只出现很少的裂纹;而在由室温升温至550℃吸氘过程中钛表面出现了由边缘向中心部分扩展的环状裂纹。钛在升温过程中的形貌变化特征与"边缘进攻"模型符合;X射线光电子能谱(XPS)测试显示,由钛氧化物、碳化物和氮化物组成的钛表面钝化层在环状裂纹形成过程中发挥了重要作用。

Deuterium induced cracking(DIC) of Ti was in-situ investigated by the hot stage microscope(HSM) technique combined with the pressure-volume-temperature(PVT) method. Results show that only several cracks are observed on the surface of Ti exposed to D2 at 550 °C, while more unique circular cracks appear when Ti is heated from room temperature to 550 °C in the D2 atmosphere. The morphology change of Ti induced by deuterium during heating is consistent with the characteristics described by the preferred edge-attack model. X-ray photoelectron spectroscopy(XPS) measurements indicate that the surface passivation layer on Ti, consisting mainly of titanium oxides, carbides and nitrides, plays an important role in the formation of circular cracks.