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8YSZ纳米粉(晶粒度为20 nm)在800~1200℃范围内煅烧12 h(温度间隔100℃),然后用大气等离子喷涂方法制备相应的涂层。对涂层的相成分、结构、结合强度、弹性模量和热震性能进行了详细分析。分析结果表明:当粉末的煅烧温度高于1000℃时,8YSZ晶粒度明显增大;涂层为双模式结构即熔化区和未熔化区,涂层的密度和熔化程度随温度升高而增加,并导致硬度和弹性模量增大;1200℃煅烧粉末所制备的涂层由于微裂纹或微孔缺陷增加,导致涂层的弹性模量减小。涂层的失效原因主要归因于热膨胀系数不匹配,涂层的热震寿命与其弹性模量呈反比关系。
8YSZ nanopowder (grain size of 20 nm) was calcined at 800-1200 ℃ for 12 h (temperature interval of 100 ℃), and then the corresponding coating was prepared by atmospheric plasma spraying. The phase composition, structure, bonding strength, elastic modulus and thermal shock resistance of the coating were analyzed in detail. The results show that the grain size of 8YSZ is obviously increased when the calcination temperature of the powder is higher than 1000 ℃. The coating is a dual-mode structure, ie, the melting zone and the unmelted zone. The density and melting degree of the coating increase with increasing temperature , Resulting in an increase in hardness and modulus of elasticity. Coatings prepared at 1200 ° C calcined powder resulted in a decrease in the modulus of elasticity of the coating due to increased microcracking or microporosity defects. The reasons for the failure of the coating are mainly attributed to the mismatch of thermal expansion coefficient, and the thermal shock life of the coating is inversely proportional to its elastic modulus.