TiO2/Al2O3微弧氧化复合涂层的制备及耐磨性研究

Fabrication and wear resistance of TiO2/Al2O3 coatings by mi-cro-arc oxidation

摘要:

本文主要利用微弧氧化方法在Ti-6Al-4V合金表面制备TiO2/Al2O3复合涂层，并揭示了O2-、AlO2-,和Ti4 在涂层生长过程中的作用机制。在高温高电压条件下，Ti-6Al-4V合金表面首先生成TiO2、Al2O3和Al2TiO5，不断放电引起的高热能导致Al2TiO5进一步分解成TiO2和Al2O3，且XRD分析表明涂层的物相组成主要是A-TiO2、R-TiO2和α-Al2O3。耐磨性测试结果表明，与基体相比TiO2/Al2O3复合涂层的显微硬度提高到1100HV，且耐磨性显著提高，磨损量降低了9.5倍。

Abstract:

The TiO2/Al2O3 composite coatings were successfully prepared on the surface of Ti-6Al-4V alloy by means of micro-arc oxidation in the Na2SiO3-(NaPO3)6-NaAlO2 solution. Its growth process revealed that O2- reacted rapidly with Ti4 (from substrate) along the reaction channels to form TiO2, and because of the addition of AlO2-, Al2O3 and Al2TiO5 were simultaneously formed. Al2TiO5 was immediately decomposed into rutile TiO2 and α-Al2O3 owing to the high thermal energy caused by discharge. Finally the prepared composite phase coatings were mainly composed of anatase TiO2, rutile TiO2 and α-Al2O3 via XRD analysis. Furthermore, the wear resistance of the TiO2/Al2O3 composite coatings enhanced about 9.5 times than that of Ti-6Al-4V alloy owing to the existence of ceramic layer.