( 1. 中國科學(xué)院 蘭州化學(xué)物理研究所固體潤滑國家重點(diǎn)實(shí)驗(yàn)室， 蘭州 730000；
2. 中國科學(xué)院 研究生院， 北京 100039)
摘 要: 在Na3PO4電解液中于恒流條件下對(duì)Ti-6Al-4V合金進(jìn)行了微弧氧化處理， 考察了氧化時(shí)間對(duì)微弧氧化膜表面形貌、 生長速率、 表面硬度和相組成的影響， 并對(duì)不同氧化時(shí)間所得微弧氧化膜的摩擦學(xué)性能和耐蝕性能進(jìn)行了表征。研究結(jié)果表明： 隨著氧化時(shí)間的延長， 氧化膜表面微孔孔徑逐漸增大， 微孔數(shù)量逐漸減少， 氧化膜生長速率逐漸減小， 氧化膜的厚度逐漸增加， 平均表面硬度呈先增大后減小的趨勢；微弧氧化膜主要由金紅石TiO2和銳鈦礦TiO2相組成，隨著氧化時(shí)間的延長， 金紅石相所占比例逐漸增大； 氧化時(shí)間的長短對(duì)微弧氧化膜的摩擦系數(shù)影響不大， 但對(duì)其磨損壽命有著顯著影響， 延長氧化時(shí)間可大大提高微弧氧化膜的磨損壽命，且隨著氧化時(shí)間的延長， 所得微弧氧化膜的腐蝕電位逐漸增大， 腐蝕電流先減小后增大。
關(guān)鍵字: 微弧氧化； Ti-6Al-4V合金； 結(jié)構(gòu)； 性能
TIAN Jun1， LIU Hui-wen1， XU Tao1
（ 1. State Key Laboratory of Solid Lubrication，
Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences，
Lanzhou 730000，China;
2. Graduate School, Chinese Academy of Sciences, Beijing 100039，China）
Abstract: Ceramic coatings were fabricated on Ti-6Al-4V alloy by micro-arc oxidation(MAO) at the constant current density of 6 A/dm2 in Na3PO4 solution. The effects of oxidation time on the surface morphologies, growth rate, surface roughness, phase composition and surface hardness of the MAO coatings obtained were investigated. Tribological properties and corrosion properties of coatings at different oxidation times were evaluated with the pin-on-disk friction and wear tester and potentiodynamic polarization tester, respectively. The results show that, with the increasing oxidation time, the number of micro-pores and the growth rate of the MAO coatings decrease, while both the size of the micro-pores and the thickness of MAO coating increase. The average surface hardness increases at the initial stage of the oxidation process, then decreases. The MAO coating is mainly composed of rutile TiO2 and anatase TiO2, and the content of rutile TiO2 increases with the increasing oxidation time. Oxidation time has little influence on the friction coefficient of the MAO coatings against GCr15 steel ball, but has much more influence on the wear life of the MAO coatings, the increase of oxidation time can improve wear life. With oxidation time increasing, the corrosion potential of the MAO coating in 3-5% NaCl(mass fraction) solution increases, but its corrosion current firstly decreases, then increases.
Key words: Ti-6Al-4V alloy; micro-arc oxidation; structure; performance
