强流脉冲电子束处理纯钛的表面组织与性能

Surface microstructure and properties of pure Ti after HCPEB treatment

研究了强流脉冲电子束处理纯钛的表层组织、显微硬度和耐蚀性能变化。经多脉冲处理的样品表面逐渐趋于平整,表层中出现非晶和纳米晶分层结构。样品表层显微硬度由原始的178 Hv提高到292 Hv。在5%NaCl溶液中进行动电位极化曲线测定,发现经15次脉冲处理样品的耐腐蚀性能最佳,自腐蚀电位由–346.4 mV提高到–188.9 mV。分析结果表明,强流脉冲电子束处理诱发高密度缺陷组织及非晶、纳米晶层结构是样品表层硬度和耐蚀性能提高的主要原因。

In this paper,we demonstrate the microstructure modification in the surface layer and the improvement in corrosion resistance and microhardness for pure Ti samples treated by high current pulsed electron beam（HCPEB）.With increasing number of pulses,the treated surfaces became relatively flatter.Multi-layer structure containing amorphous layer and nano-crystalline layer in the near surface of the treated pure Ti samples was also examined.Microhardness of the treated samples was increased from the initial 178 Hv to 292 Hv.According to the potentiodynamic polarization curves,the treated samples exhibited improved corrosion resistance in 5% NaCl solution compared with the virgin.Of all the samples,the 15-pulse treated sample is of the best corrosion resistance with the corrosion current increased from the initial –346.4 mV to –188.9 mV.The defects such as high dislocation density as well as the formation of amorphous and nano-crystalline layers induced by the HCPEB treatment were believed to be reasons for the improvements in corrosion resistance and microhardness.