钛合金表面梯度Al_2O_3陶瓷涂层的高温抗氧化性能  

High-temperature Anti-oxidation Property of Al_2O_3 Gradient Composite Coatings on TC11 Alloys

作　　者：杜文博[1] 姚正军[1] 陶学伟[1] 罗西希[1] DU Wenbo YAO Zhengjun TAO Xuewei LUO Xixi(College of Material and Science Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016)

机构地区：[1]南京航空航天大学材料科学与技术学院,南京210016

出　　处：《材料导报》2017年第14期57-60,共4页Materials Reports

基　　金：国家自然科学基金(51371097);江苏高校优势学科建设工程资助项目;江苏省"六大人才高峰"资助项目(16005-PT)

摘　　要：钛合金应用广泛,但在高温环境中极易被氧化,降低其力学性能及寿命。利用溶胶-凝胶法在TC11钛合金上制备梯度层(ZrO_2+Al_2O_3)+表层(Al_2O_3)的复合梯度涂层,提高其高温抗氧化能力。将复合梯度涂层、单层氧化铝涂层以及基体在700℃进行100h的高温氧化,利用氧化增重数据拟合得到梯度涂层的氧化速率为0.015mg^2/(cm4·h),氧化指数为2.137,并结合氧化后EDS成分分布,发现复合梯度涂层可以提高基体的高温抗氧化性能。同时利用700℃热震实验比较了复合梯度氧化铝涂层试样和单层氧化铝陶瓷试样的热震次数,梯度层(ZrO2+Al_2O_3)的存在缓解了基体与氧化铝陶瓷涂层之间热膨胀系数不匹配而导致的易剥落的问题,延长了涂层寿命,进一步提高了基体的高温抗氧化能力。Aiming at mitigating the high-temperature oxidation of titanium alloy which causes mechanical properties deterioration and lifetime reduction,agradient composite coating composed of gradient alumina（ZrO2＋Al2O3）and Al2O3 via a sol-gel method（with the advantage of ease of composition control）on the surface of TC11 titanium alloy.Experiment were carried out among gradient coating,Al2O3 coating and matrix,and an oxidation rate of 0.015mg^2/（cm^4·h）and an oxidation index of 2.137 for the gradient coating were obtained from the fitting results of weight gain data after 700 ℃-100 hoxidation.It can be concluded that the high-temperature oxidation resistance of the gradient coating is better than the others taking into account weight gain curve and EDS analysis upon the oxidized samples.Thermal shock test at 700℃confirms the better match of thermal expansion coefficient between matrix and Al2O3 outer layer for gradient coating（ZrO2＋Al2O3）,inferring the mitigation effect due to the chemical composition gradient to the mismatch which further benefits the promotion of resistance toward high-temperature oxidation and lifetime prolongation of titanium alloy matrix.

关 键 词：溶胶-凝胶 钛合金 高温抗氧化 热膨胀系数 梯度 

分 类 号：TG174.45[金属学及工艺—金属表面处理]