(南京航空航天大學 機電學院，南京 210016)
摘 要: 采用動態(tài)電位極化和交流阻抗方法研究工業(yè)純鈦(CP-Ti Grade 2)和鈦鈀合金(Ti-0.2Pd Grade7)在模擬體液中的耐蝕性；研究熱處理和等通道徑角擠壓(ECAP)處理獲得的兩種鈦金屬的顯微組織對耐蝕性的影響；利用交流阻抗譜對各種處理方式得到的表層特征進行研究。結(jié)果表明：ECAP處理大幅度提高了兩種金屬的耐蝕性，馬氏體組織的CP-Ti比魏氏組織的CP-Ti具有更高的耐蝕性，均勻等軸粗晶的空冷CP-Ti的腐蝕電流密度較低。ECAP處理的Ti-0.2Pd表面顯示雙層膜結(jié)構(gòu)，其余處理方式的試樣表面顯示具有單層膜結(jié)構(gòu)。
關(guān)鍵字: 純鈦；Ti-0.2Pd合金；電化學；耐腐蝕性；顯微組織
（College of Mechanical and Electrical Engineering,
Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China）
Abstract:The corrosion resistance of commercial pure titanium (CP-Ti) and Ti-0.2Pd alloy in a simulated body fluid was investigated by cyclic polarization and electrochemical impedance spectroscopy (EIS). The effect of microstructure obtained by heat treatment and equal-channel angular pressing (ECAP) on the corrosion resistance was also studied for two kinds of metals. The properties of surface produced by different microstructures were characterized by the EIS analysis. The results show that both metals composed of martensitic phase have higher corrosion resistance than the metals composed of Widmannstatten phase. ECAP process can improve the corrosion resistance of both metals evidently. A coarse equiaxial-grained CP-Ti with homogeneous microstructure shows low corrosion current density. The surface on ECAPed Ti-0.2Pd shows double layer structure, and the surface on the rest of specimens show single layer structure.
Key words: pure Ti; Ti-0.2Pd alloy; electrochemical; corrosion resistance; microstructure
