火焰喷涂热障陶瓷梯度涂层的制备工艺及性能

在优化热障梯度涂层和过渡层的成分设计及氧乙炔火焰法制备工艺的基础上，获得了组织致密，有良好冶金结合的Al2O3／Fe热障梯度涂层。结果表明，涂层中的Al2O3分布基本均匀，且在整个涂层中，从钢基体到涂层表面的化学成分呈梯度分布，涂层与钢基体及各涂层之间存在明显的冶金结合；所获得的Al2O3热障梯度涂层与普通纯Al2O3热障涂层和带底层（Ni）和过渡层（Cu）的热障涂层相比，与基体间的结合力显著提高，弯曲强度、耐热冲击性能大为增强，涂层热障效果随涂层的数量和Al2O3含量的增加也获得明显提高。

Preparation and properties of thermal barrier ceramics gradient coating by flame spraying

With optimizing the chemical compositions of the coating layer and the transition layer, a dense Al_2O_3/Fe thermal barrier gradient coating with a sound metallurgical bonding was prepared using an oxyacetylene flame spraying. The results show that the Al_2O_3 distributes uniformly in the coating. An excellent metallurgical bonding between the steel base and the coating as well as a graded distribution of the chemical compositions from the base to the coating surface is obtained. As compared with the conventional Al_2O_3 thermal barrier coating and the thermal barrier coating using the Ni as bottom layer and the Cu as transition layer, the bonding strength, flexural strength and heat shock resistance improve significantly. The efficiency of the thermal barrier is found to increase with the amounts of the coating layers and the content of the Al_2O_3.