微弧等离子喷涂碳纳米管/纳米Al_2O_3-TiO_2复合涂层高温性能研究  

High Temperature Performance of Micro-plasma Sprayed CNTs/Al_2O_3-TiO_2 Composite Coating

作　　者：汪刘应[1,2] 徐卓[1] 华绍春[2] 刘顾[2] 

机构地区：[1]西安交通大学电信学院,西安710049 [2]第二炮兵工程学院,西安710025

出　　处：《无机材料学报》2011年第3期239-243,共5页Journal of Inorganic Materials

基　　金：国家自然科学基金(50845039)~~

摘　　要：采用等离子喷涂技术制备了5wt%CNTs/Al2O3-TiO2复合涂层,借助SEM、热红联仪和RAM反射率测试系统对CNTs/Al2O3-TiO2复合涂层的组织结构、高温氧化性能、电磁特性进行了分析.结果表明:CNTs/Al2O3-TiO2复合涂层的组织结构致密、孔隙率低,CNTs分散均匀,碳纳米管与Al2O3-TiO2陶瓷粘结剂之间具有良好的界面相容性.在20～700℃高温氧化过程中,CNTs起始失重温度为471.29℃,CNTs/Al2O3-TiO2复合涂层的高温氧化性能有一定提高,起始失重温度从471.29℃提高到507.8℃,而碳纳米管的失重率从100%下降到33.68%.CNTs/Al2O3-TiO2复合涂层具有较好的高温吸波性能,25℃时复合涂层的反射率峰值为-7.86dB.随温度的升高,CNTs/Al2O3-TiO2复合涂层的反射率峰值不断减小,谐振频率向低频移动,300℃时复合涂层的反射率峰值为-12.88dB,小于-5dB频带宽为4.48GHz.5wt% CNTs/Al2O3-TiO2 coatings were prepared by micro-plasma spraying.Microstructure and high temperature properties of CNTs/Al2O3-TiO2 composite coatings were studied.Its microstructure was dense and the porosity was low.CNTs were dispersed uniformly in CNTs/Al2O3-TiO2 composite coating.In the thermal oxidation process from 20℃ to 700℃,the initial weight loss temperature of CNTs was 471.29℃.The initial weight loss temperature of CNTs/Al2O3-TiO2 composite coating was raised to 507.8℃.The plasma heating process improved the graphite phase transformation of CNTs,which was helpful for the improvement of initial weight loss temperature of CNTs/Al2O3-TiO2 composite coating.When CNTs/Al2O3-TiO2 composite coating was heated to 300℃,and the high temperature reflectivity was measured at 2 18 GHz,the minimum reflection loss was 7.86 dB at 25 ℃.With increasing temperature,the reflectivity peak continuously decreased and the resonant frequency moved to the low frequency.The experimental reflectivity peak was 12.88dB,and the frequency bandwidth for less than 5dB was 4.48 GHz at 300℃.The results suggests that CNTs/Al2O3-TiO2 coating is a good candidate for high-temperature microwave-absorbing material.

关 键 词：微弧等离子喷涂 CNTs/Al2O3-TiO2 高温性能 电磁特性 

分 类 号：TB332[一般工业技术—材料科学与工程]