【摘要】 以商业硅胶为原料,采用溶胶-凝胶法在Ti-22Al-26Nb合金表面浸涂制备非晶氧化硅涂层.涂层样品和空白样品在800和900℃静态空气中进行等温氧化实验,900℃静态空气中进行循环氧化实验.采用热重分析(TGA)、扫描电子显微镜(SEM)和X射线衍射(XRD)对结果进行分析,研究涂层对Ti-22Al-26Nb合金氧化行为的影响.结果表明:涂层样品的氧化抛物线速率常数较空白样品降低,涂层提高了合金在空气中的抗氧化能力.合金表面生成氧化膜主要由TiO2,Nb2TiO7和AlNbO4组成,涂层抑制了氧化物的生长.探讨了涂层的作用机制.更多还原

【Abstract】 Silica coating was deposited on an orthorhombic phase Ti-22Al-26Nb alloy by Sol-gel processing.Isothermal oxidation at 800 and 900 ℃ and cyclic oxidation at 900 ℃ in static air of the specimens were carried out to investigate the effect of the silica coating on the oxidation behavior of the Ti-22Al-26Nb alloy using thermogravimetry,SEM and XRD.The average parabolic rate constants of the coated specimens were lower than those of uncoated ones.Additionally,the coating exhibited a beneficial effect on the cyclic oxidation resistance of the alloy in air.TiO2,Nb2TiO7 or AlNbO4 were formed on the substrate alloys.The coating could inhibit the growth of the oxides.The possible mechanism of the coating on the oxidation behavior of the alloy was discussed.更多还原