TC4钛合金微弧氧化-溶胶凝胶复合涂层的制备及其抗高温氧化性能

High Temperature Oxidation Resistance Properties of Composite Coatings on TC4 Titanium Alloy Prepared by Micro-arc Oxidation and Sol-gel

为了提高钛合金的使用温度,设计并制备了一种微弧氧化(MAO)-氧化钇稳定氧化锆(YSZ)的陶瓷复合涂层。采用微弧氧化(MAO)技术在TC4钛合金基体表面原位生长出一层氧化铝陶瓷层(TM涂层),然后采用溶胶-凝胶法(Sol-gel)在MAO层的基础上制备低导热系数的钇稳定氧化锆(YSZ)涂层,最终制备出MAO-YSZ复合涂层(TMY复合涂层)。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和能谱仪(EDS)分析涂层的相结构、组织形貌和成分,并测定了TC4、TM涂层以及TMY复合涂层在700℃下的氧化动力学曲线。结果表明:TMY复合涂层外层以ZrO2为主,内层主要为Al2O3。具有TMY复合涂层的钛合金在700℃下氧化100h后其氧化增重仅为无涂层钛合金的14%,说明TMY复合涂层可以显著提高钛合金的抗高温氧化性能与使用温度。

In order to improve the service temperature of the titanium alloy, a microarc oxidation （MAO） yttriastabilized zirconia （YSZ） composite ceramic coatings was prepared on the TC4 titanium alloy substrate. An oxide ceramic layer（TM coating）was prepared on TC4 titanium alloy by micro arc oxidation （MAO） method. Then, a YSZ coating（TMY coating）with low thermal conductivity was prepared by solgel method. The phase composition, morphologies and element contents of the coatings were investigated by XRD, SEM and EDS. The oxidation kinetics characteristic of the uncoated TC4, TM coating and TMY composite coating were examined at 700 ℃. The results show that the outer layer of the TMY coating is mainly composed of ZrO2, and the inner layer is Al2O3. At 700 ℃ after 100 h treatment, the weight gain of the TMY composite coating is only 14% of that the uncoated TC4 , indicating that the composite coatings can improve the high temperature resistance property of Ti alloy.