Commercial pure titanium TA2 was processed with the thermal oxidation at 500 ℃ for 30 min or at 650℃for 30 min or at 800℃for 30 min,then processed with diffusion at 800℃for 20 h.The microstruc-ture of the treated TA2 samples was evaluated using optical microscopy,scanning electron microscopy with energy dispersive spectrometry and X-ray diffractometer.The results exhibited that a relatively hard and deep diffusive layer was formed on the surface of the treated samples.Subsequently,the cavitation erosion behavior of the treated samples was studied in distilled water by using an ultrasonic vibratory apparatus.It is estimated that the thermal oxidation/ diffusion treatments could improve the cavitation erosion resistance of the TA2 samples.The oxygen diffused zone with a hard and dense microstructure can suppress the crack initiation de-cay crack propagation path at the surface,and then increase in the cavitation erosion resistance of the treated samples.%利用热氧化/氧扩散工艺对纯钛TA2表面进行处理,TA2先分别经500 ℃、30 min,650 ℃、30 min和800 ℃、30 min热氧化处理,随后进行800 ℃、20 h氧扩散处理.处理后的试样利用金相显微镜,扫描电子显微镜、X射线衍射仪和显微硬度测试仪分别进行表面形貌、物相和硬度的测试分析.结果表明,热氧化/氧扩散工艺在试样表面制得一定厚度的硬化层,表面硬度得到显著提高且沿深度方向硬度快速减小.室温下在去离子水中,采用磁滞伸缩振动空蚀设备对试样的抗空蚀性能进行测试.结果表明,利用热氧化/氧扩散工艺对TA2表面改性可以显著地改善TA2的抗空蚀性能,而这主要归咎于致密的氧扩散层在空蚀过程中可以有效地抑制裂纹的萌生、扩展.
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