TiAlN涂层对钛合金的热腐蚀防护作用研究

Study on Hot Corrosion Protection Effect of TiAlN Coating on Titanium Alloy

摘要:

钛合金在高温含盐环境下服役时，易发生高温腐蚀现象。为了提高钛合金抗高温腐蚀性能，采用离子镀技术在TC4钛合金基体上沉积了TiAlN涂层，并研究了涂层的抗高温腐蚀防护性能。研究结果表明：TiAlN涂层结构均匀稳定、与基体结合良好，表面生成了少量的熔滴颗粒，涂层由Ti(Al)N物相组成；TC4基体经550 ^oC腐蚀后，在表面形成了尺寸较大的凸起，较厚的腐蚀产物膜由TiO₂相组成，腐蚀产物的结构疏松、分层、无保护性，表明TC4基体的抗腐蚀性较差；而TiAlN涂层表面的熔滴被氧化腐蚀，在涂层上方形成了一层均匀、致密、连续的Na₂Al₂Ti₆O₁₆钠盐产物膜，涂层内部并未出现开裂、分层现象，表现出涂层较好的抗腐蚀性。

Abstract:

Titanium alloys are prone to high-temperature corrosion when they are used in high-temperature salt-containing environments. In this study， a TiAlN coating was deposited on a TC4 titanium alloy substrate by ion plating technology， and the protective effect of the coating on high temperature corrosion of the substrate was investigated. The results showed that the TiAlN coating had a uniform and stable structure， as well as good bonding with the substrate. A small amount of droplet particles was formed on the surface， and the coating was composed of Ti（Al）N phase. The high-temperature corrosion experiment found that the surface of TC4 substrate was corroded at 550 ^oC to form large bumps， and the thick product film was composed of TiO₂ phase， indicating the poor corrosion resistance of the TC4 substrate. Instead， the droplets on the surface of the TiAlN coating were oxidized and corroded， and a uniform， dense and continuous Na₂Al₂Ti₆O₁₆ sodium salt product film was formed on the coating. There was no cracking or delamination inside the coating， indicating good corrosion resistance of the TiAlN coating.