共查询到16条相似文献,搜索用时 140 毫秒
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本文采用含多种氧化物的煤矸石粉末,以加钙活化的煤矸石和未加钙的煤矸石两种配方为涂层骨料,用热化学反应法在Q235钢表面制备陶瓷涂层.通过XRD分析球磨前后粉体及陶瓷涂层的相结构,并分析涂层的抗热震性和耐蚀性能.结果表明,通过热化学反应法制备煤矸石陶瓷涂层是可行的,制备过程中产生Al6Si2O13、Al2 SiO5、AINi、CaAl2 Si2O8及玻璃新相.涂层的性能比基体有了很大的提高,其中煤矸石陶瓷涂层的耐酸、碱、盐性分别提高4.31倍、2.08倍、2.06倍;加钙煤矸石陶瓷涂层分别提高9.79倍、2.38倍、2.86倍. 相似文献
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采用热化学反应方法在N80钢基体表面制备了陶瓷涂层。通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)、体视显微镜和划痕仪对涂层的物相结构、组织形貌和膜基界面结合力进行了研究,利用失重法在20%的质量分数盐酸溶液中测试了涂层的耐蚀性能。结果表明:在600℃固化温度下,以SiO2粉体和SiO2、Al2O3、MgO等两类不同骨料制得的陶瓷涂层中,前者无新相生成,涂层与基体界面结合力24 N;后者有新相MgAl2O4生成,且涂层比较致密,涂层与基体界面结合力约40 N。以水玻璃作粘结剂的复合氧化物陶瓷涂层的表面致密度、平整性均优于以磷酸氢铝作粘结剂的涂层。酸腐蚀测试表明,以水玻璃作粘结剂的复合氧化物陶瓷涂层的平均腐蚀速率约为基体的1/2左右。 相似文献
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R. D. Kapustin L. B. Pervukhin V. S. Vladimirov S. E. Moizis 《Glass Physics and Chemistry》2008,34(4):480-484
The possibility of performing the thermochemical synthesis in the M1 oxide ceramic coating under surface heating in order to produce mullite structures is considered with the aim of extending the field of application of protective oxide ceramic coatings and decreasing the power consumption. The coating is applied to a ShA chamotte brick. Then, the synthesis of mullite and mullite-like structures is provided with the use of surface heating by thermochemical compositions and the thermal insulation prepared from the refractory cellular concrete for the control of the heat removal. 相似文献
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针对燃煤锅炉受热面存在的高温腐蚀问题,采用料浆法在20G钢材表面制备复合陶瓷涂层,烧结后的复合陶瓷涂层表面较为致密,涂层与基材具有良好的结合状态。对喷涂及未喷涂陶瓷涂层钢片在SO2腐蚀气氛环境下的抗高温腐蚀性能进行试验,并采用热分析动力学方法对试验数据进行处理,结果表明,在400~500℃温度范围内,两种试样的腐蚀过程均符合一维扩散反应动力学模式,计算求得喷涂涂层钢片腐蚀反应活化能低于未喷涂涂层钢片,涂层具有较好的抗高温腐蚀性能。对腐蚀试验后试样的形貌、成分和物相分析结果显示,涂层在SO2气氛下腐蚀后,表面生成K2SO4晶粒,但由于涂层较为致密,阻止了S的扩散,内部基本没有检测到K2SO4的存在。 相似文献
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《应用陶瓷进展》2013,112(3):99-102
AbstractThe applicability of electrophoretic deposition (EPD) for the fabrication of single layer and multilayer ceramic coatings on dense ceramic composite materials has been examined. Al2O3/Y-tetragonal zirconia polycrystal (TZP) functionally graded composites of tubular shape were successfully coated with a two layer coating comprising porous alumina and dense reaction bonded mullite layers. The dual layer coating structure was designed to eliminate the numerous cracks caused by volume shrinkage during sintering of the individual EPD formed layers. In another example, mullite fibre reinforced mullite matrix composites were coated with a thin layer of nanosized silica particles using EPD. The aim was to achieve a compressive residual stress field in the silica layer on cooling from sintering temperature, in order to increase composite fracture strength and toughness. The EPD technique proved to be a reliable method for rapid preparation of single layer and multilayer ceramic coatings with reproducible thickness and microstructure on ceramic composite substrates. 相似文献
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Gustavo Costa Bryan J. Harder Valerie L. Wiesner Dongming Zhu Narottam Bansal Kang N. Lee Nathan S. Jacobson Denys Kapush Sergey V. Ushakov Alexandra Navrotsky 《Journal of the American Ceramic Society》2019,102(5):2948-2964
The thermodynamic stability of ceramic coatings with respect to their reaction products is crucial to develop more durable coating materials for gas-turbine engines. Here, we report direct measurements using high-temperature solution calorimetry of the enthalpies of reaction between some relevant ceramic coatings and a corrosive molten silicate. We also report the enthalpy of mixing between the coatings and molten silicate after combining the results measured by high-temperature solution calorimetry with enthalpies of fusion measured by drop-and-catch calorimetry and differential thermal analysis. The enthalpies of solution of selected silicate and zirconia-based coatings and apatite reaction products are moderately positive except for 7YSZ, yttria-stabilized zirconia. Apatite formation is only favorable over coating dissolution in terms of enthalpy for 7YSZ. The enthalpies of mixing between the coatings and the molten silicate are less exothermic for Yb2Si2O7 and CaYb4Si3O13 than for 7YSZ, indicating lower energetic stability of the latter against molten silicate corrosion. The thermochemical results explain and support the very corrosive nature of CMAS melts in contact with ceramic coatings. 相似文献