钛表面辉光等离子渗钯过程中Pd在钛中扩散行为的研究

Palladium Diffusion in Pure Titanium during Glow Plasma Surface Palladiuming Process

采用辉光等离子冶金技术在纯钛表面制备了Ti-Pd合金层,用XRD、SEM和EDS研究合金层的相组成、微观组织和元素分布。结果表明:900℃渗钯时,Ti-Pd合金层大体分为3层,各层间Pd元素的浓度有明显的突变,Pd在Ti中的扩散属于反应扩散。室温状态时,合金层从表层到基体分别是:Ti Pd3相层,α-Ti Pd相层,Ti2Pd相层。推测合金层在高温状态时,从表层到基体分别是:Ti Pd3相层,β-Ti Pd相层,Pd在β-Ti中的饱和固溶体层。各层的长大速率基本满足抛物线规律,Pd在Ti中的扩散以体扩散为主。

Ti-Pd alloy coating was prepared on the surface of C.P.Ti by a glow plasma surface metallurgy process. The phase composition, microstructure and element distribution of the Ti-Pd coating were studied by XRD, SEM and EDS, respectively. The results show that the Ti-Pd alloy coating has 3 layers, the concentration of Pd between each layer has obviously mutation at 900 ℃, and the diffusion of Pd in Ti is reaction diffusion. At room temperature, the top layer is TiPd3 phase, below the top layer is a-TiPd phase and Ti2Pd phase along the coating depth direction. It is speculated that the top layer is TiPd3 phase, below top layer is fl-TiPd phase and saturated solid solution of Pd in Ti along the coating depth direction at high temperature. Growing rate of each layer basically obeys the parabolic rate law, and the primary diffusion of Pd in Ti is bulk diffusion.