TiO_2/Al_2O_3微弧氧化复合涂层的制备及耐磨性研究（英文）

Fabrication and Wear Resistance of TiO_2/Al_2O_3 Coatings by Micro-arc Oxidation

主要利用微弧氧化方法在Ti-6Al-4V合金表面制备Ti O_2/Al_2O_3复合涂层,并揭示了O^(2-)、Al O_2^-,和Ti^(4+)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Ti O_2、Al_2O_3和Al_2Ti O_5,不断放电引起的高热能导致Al_2Ti O_5进一步分解成Ti O_2和Al_2O_3,且XRD分析表明涂层的物相组成主要是A-Ti O_2、R-Ti O_2和α-Al_2O_3。耐磨性测试结果表明,与基体相比Ti O_2/Al_2O_3复合涂层的显微硬度HV提高到11000 MPa,且耐磨性显著提高,磨损量降低了9.5倍。

Ti O_2/Al_2O_3 composite coatings were prepared on the surface of Ti-6Al-4V alloy by micro-arc oxidation in the Na_2 Si O_3-（Na PO_3）_6-Na Al O_2 solution. The growth process reveals that O_2-reacts rapidly with Ti^（4＋）（from substrate） along the reaction channels to form Ti O_2, and because of the addition of Al O_2-, Al_2O_3 and Al_2 Ti O_5 are simultaneously formed. Al_2 Ti O_5 is immediately decomposed into rutile Ti O_2 and α-Al_2O_3 owing to the high thermal energy caused by discharge. Finally the prepared composite phase coatings are mainly composed of anatase Ti O_2, rutile Ti O_2 and α-Al_2O_3 via XRD analysis. Furthermore, the microhardness HV increases and maintains at about 11 000 MPa, and the wear resistance of the Ti O_2/Al_2O_3 composite coatings is enhanced by about 9.5 times than higher that of Ti-6Al-4V alloy owing to the existence of ceramic layer.