MOCVD制备中温TiO_2-Al_2O_3复合涂层及其抑焦性能研究

Preparation and anti-coking performance of TiO_2-Al_2O_3 composite coatings by MOCVD

本文以异丙醇钛和仲丁醇铝为原料,采用金属有机化学气相沉积(MOCVD)共沉积法在310S不锈钢表面制备不同温度TiO_2-Al_2O_3复合涂层,并采用扫描显微镜、能量散射X射线光谱表征了复合涂层的表面形貌、厚度、元素组成。结果显示:不同复合涂层厚度均随沉积时间增加而增加,涂层均匀致密,复合涂层中Ti、Al、O三种元素含量随沉积温度线性变化。晶型测试表明:250℃和300℃沉积复合涂层为无定型的TiO_2和Al_2O_3构成,350℃和400℃时复合涂层的晶型结构为锐钛矿相的TiO_2和无定型的Al_2O_3。不同温度沉积TiO_2-Al_2O_3复合涂层试样结焦评价后积碳量均较310S空白试样大大减少,400℃沉积复合涂层试样表面没有丝状积碳出现,表明复合涂层具有较好的抑制金属催化结焦效果。

In this work,the TiO2-Al2O3 composite coatings were prepared by the metal organic chemical vapor deposition on the surface of 310 S type stainless steel.The topography,thickness,and elemental composition of TiO2-Al2O3 composite coating were characterized by Scanning Electron Microscope and energy scattering X.It can be indicated that the thickness of the composite coating grew with increasing deposition time.The composite coatings were uniform and dense with Ti,Al,O contents changing linearly with the deposition temperature.The crystal structures of composite coatings are amorphous TiO2 and Al2O3 for the samples deposited at 250 °C and 300 °C,and anatase phase of TiO2 and amorphous Al2O3 for those at 350 ° C and 400 ° C. The mass of coking on the TiO2-Al2O3 composite coatings deposited at different temperatures were significantly lower than those of 310 S,and there was no filamentous carbon found on the surface of the composite coating deposited at 400 °C,indicating that the composite coating can effectively inhibit coking due to metal catalysis.