等离子喷涂金属/陶瓷梯度热障涂层研究进展

Research Progress of Metal/Ceramic Gradient Thermal Barrier Coatings by Plasma Spraying

热障涂层在众多领域具有重要的应用价值,但基体与涂层的物理性能不匹配是遏制其服役性能和寿命提高的主要原因。金属/陶瓷梯度热障涂层通过逐渐改变涂层内部的成分、结构,可有效地改善基体和涂层因物理性能突变而导致的界面失效问题。首先介绍了金属/陶瓷梯度热障涂层对比于双层热障涂层的独特微观结构,并简要分析了其具有明显性能优势的原因。随后总结了金属/陶瓷梯度热障涂层残余应力的具体分布、影响因素和模拟模型优化现状,重点从优化涂层制备工艺、改进喷涂技术、改善涂层设计三个方面,介绍了改善涂层性能的研究进展。其中优化球磨和喷涂工艺参数、模拟研究喷涂过程、改进喷涂技术的方式是通过提高涂层质量来提升其物理性能,而改变涂层成分分布形式、涂层层数和厚度主要是通过改善涂层残余应力分布和水平来提升其抗热失效能力。最后提出了进一步优化模拟模型、改进喷涂技术、创新涂层设计和完善机理研究,是未来等离子喷涂金属/陶瓷梯度热障涂层的重点研究方向。

Thermal barrier coating has important application value in many fields,but the mismatching between the physical properties of the substrate and the coating is the main reason restraining the improvement of its service performance and service life.Metal/ceramic gradient thermal barrier coating can effectively improve the interface failure caused by sudden changes in physical properties of the substrate and coating by gradually changing the internal structure and composition of the coating.The unique microstructure of metal/ceramic gradient thermal barrier coatings was introduced compared with double layer thermal barrier coatings and the reasons for its obvious performance advantages were briefly analyzed.The residual stress distribution,influencing factors and simulation model optimization of metal/ceramic gradient thermal barrier coatings were summarized later.The research progress of improving coating properties from three aspects:optimizing coating preparation process,improving spraying technology and strengthening coating design was described.Among them,optimizing the process parameters of ball mill and spraying,simulating the spraying process and improving the spraying technology and methods were to improve the physical properties of the coating by improving the quality of the coating.Changing the distribution form of coating composition,coating layer number and thickness was mainly to improve the thermal failure resistance of the coating by improving the residual stress distribution and level.With the continuous development of science and technology,it is proposed that further optimization of simulation model,improvement of spraying technology,innovation of coating design and improvement of mechanism research are the key research directions of plasma spraying metal/ceramic gradient thermal barrier coating in the future.