{首页主词},&

Ti6Al4V鈦合金滲碳層在HF中的腐蝕行為

2021-05-06 16:33:50 作者：李坤茂來源：材料研究學報分享至：

摘要

用真空感應滲碳方法對Ti6Al4V鈦合金進行高速滲碳，研究了滲碳層在HF溶液中的腐蝕行為。對腐蝕前后滲碳層的相結構和形貌的分析發(fā)現(xiàn)：對Ti6Al4V鈦合金高速滲碳后，在表面生成一層TiC和CTi0.42V1.58復合化合物相的滲碳層。因為表面有滲碳層，Ti6Al4V鈦合金在濃度為0.2%的HF中？泡其腐蝕速率從4.65×10-10 g·m-2·h-1降低到3.3×10-10 g·m-2·h-1。電化學腐蝕測試結果表明，其自腐蝕電位從未滲碳時的-0.94 V升高到-0.68 V,腐蝕電流密度從4.10 mA·cm-2降至1.65 mA·cm-2,極化電阻從6.36 Ω·cm2增大到15.8 Ω·cm2,Rt從0.2 Ω·cm2增大到5.7 Ω·cm2。滲碳層具有n型半導體特性，未滲碳樣品具有p型半導體特性。Ti6Al4V鈦合金滲碳后，在腐蝕過程中電子轉移的阻力增大，使耐蝕性提高。F-對Ti6Al4V鈦合金滲碳層的腐蝕機理，主要是析氫腐蝕。

關鍵詞：材料表面與界面 ; 滲碳 ; 感應加熱 ; Ti6Al4V ; 組織 ; 腐蝕行為

Abstract

The rapid carburization of Ti6Al4V titanium alloy was carried out by vacuum induction carburizing method. The corrosion behavior of carburized Ti-alloy in HF solution was investigated. Results show that after rapid carburization a layer of TiC and CTi0.42V1.58 composite compound was formed on the surface of T-alloy, and in comparison with the blank Ti-alloy, the corrosion rate in 0.2% HF solution decreases from 4.65×10-10 g·m-2·h-1 to 3.3×10-10 g·m-2·h-1 for the carburized Ti-alloy. Correspondingly, the free-corrosion potential increased from -0.94 V to -0.68 V, the corrosion current density decreased from 4.10 mA·cm-2 to 1.65 mA·cm-2, the polarization resistance increases from 6.36 Ω·cm2 to 15.8 Ω·cm2 and Rt increases from 0.2 Ω·cm2 to 5.7 Ω·cm2. The corrosion product of carburized layer mainly exhibits n-type semiconductor characteristics, and that of the blank Ti-alloy exhibits p-type semiconductor characteristics. The corrosion mechanism of F- on the carburized layer of Ti6Al4V Ti-alloy is mainly hydrogen evolution corrosion.

Keywords： surface and interface ; carburizing ; induction heating ; Ti6Al4V ; microstructure ; corrosion behavior