NiCrFe金属上涂覆玻璃陶瓷涂层的结构和性能

Microstructure and Properties of Glass Ceramic Coating on the NiCrFe Metal Support

摘要:

以硝酸铝Al(NO3)3·9H2O和正硅酸四乙酯(TEOS)为主要原料，采用溶胶-凝胶法在镍铬铁合金(NiCrFe)载体上制备不同硅铝摩尔比的玻璃陶瓷涂层，研究不同制备条件对涂层形貌、结晶质量及结合强度的影响。XRD、SEM及热冲击、超声振荡、拉伸试验结果表明，与传统涂层相比，该涂层可以提高比表面积，增强柴油车金属基(NiCrFe)后处理器与催化剂的结合强度，且焙烧温度较低，制备工艺简单。其中，载体经900 ℃预处理，硅铝摩尔比为5:1的涂层经70 ℃烘干2 h，650 ℃焙烧2 h后得到最佳样品

Abstract:

Glass-ceramic coating of different molar ratios deposited on the metal support (NiCrFe alloy) was prepared by a sol-gel method, with tetra-ethyl orthosilicate (TEOS) and aluminium nitrate (Al(NO3)3·9H2O) as the starting materials. The effects of different preparation parameters on the morphology, crystal quality and the bonding strength of the coating were studied. Characterization of XRD and SEM and the tests of thermal shock, ultrasonic vibration and tension show that the coating can increase the specific surface area and enhance the bonding strength between the metal support (NiCrFe alloy) of diesel engine catalytic converters and the coating. Moreover, the calcination temperature of the coating is lower and the preparation is much simpler than the traditional ones. Optimal parameters are found to be as follows: pre-oxidation of the metallic supports should be performed at 900 oC, the molar ratio of silicon to aluminum is 5:1, the coating drying is performed at 70 oC for 2 h and calcining is at 650 oC for 2 h.