关键词: 
强流脉冲电子束 /
亚稳&beta /
钛合金 /
表面处理 /
组织结构

摘要: 采用强流脉冲电子束对含有 α+ β两相的亚稳 钛合金进行了表面处理。处理使用的电子束加速电压为27 kV，脉冲次数分别为5，10 和25 次，脉冲持续时间为2 s。采用金相显微镜、扫描电子显微镜、电子背散射衍射和X射线衍射等技术对处理后的样品表面形貌和组织结构进行分析。结果表明，5 次脉冲处理样品表面呈现波状特征，增加脉冲处理，样品表面变得较为平坦且出现了层片状特征；处理后样品表层α 相逐渐消失，出现了应力诱发的α′′ 马氏体组织。

High current pulsed electron beam (HCPEB) surface treatment of a metastable titanium alloy that initially consisted of an + double-phase microstructure has been employed with a various treating parameters. The parameters taken are as follows: accelerating voltage, 27 kV; pulse numbers, 5, 10 and 25, respectively; pulse duration, 2 s. The microstructure and surface morphology changes occurring in the modified surface were investigated with optical microscopy, scanning electron microscopy, electron backscatter diffractometry and X-ray diffractometry techniques. We found that the sample surface showed a wavy aspect after 5 pulse treatment. After 25 pulses, the treated sample turned flatter and showed a lamellar structure. Meanwhile the initial phase in the surface layer diminished gradually while increasing the number of pulses. On the contrary, the ′′ martensite phase induced by the stress generated by the HCPEB treatment was found in melted layer of the treated samples.