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为了改善等离子喷涂ZrO2 涂层的抗热震性能 ,利用热震试验、SEM和EPMA等技术 ,研究了SiO2 添加剂对其显微组织和抗热震性能的影响 .当SiO2 添加剂质量分数小于 3 .0 %时 ,涂层的抗热震性能随SiO2 添加剂的质量分数的增加而提高 ;当其质量分数大于 3.0 %时 ,涂层的抗热震性能随其质量分数的增加而降低 ,3.0 %SiO2 +ZrO2 涂层的抗热震起裂次数和抗热震失效次数达到最大值 ,分别由不添加SiO2 涂层时的 32次和 46次提高到 83次和 112次 .在ZrO2 涂层中添加SiO2 会促使涂层中形成气孔 ,并且气孔率和气孔直径随SiO2 添加量的增加而增加 .3 .0 %SiO2 +ZrO2 涂层中形成分布均匀、直径约为 1μm的气孔 ,其气孔率约为 10 % ,此时 ,涂层的弹性模量和所受到的应力最小 ,因而涂层的抗热震性能最好
In order to improve the thermal shock resistance of plasma sprayed ZrO2 coating, the effects of SiO2 additives on the microstructure and thermal shock resistance were studied by means of thermal shock test, SEM and EPMA.When the mass fraction of SiO2 additive is less than 3.0 %, The thermal shock resistance of the coating increases with the mass fraction of SiO2 additives. When the mass fraction is more than 3.0%, the thermal shock resistance of the coating decreases with the increase of the mass fraction of SiO2. When 3.0% SiO2 + The number of thermal shock cracking and thermal shock failure of ZrO2 coating reached the maximum value, which was increased from 32 times and 46 times without addition of SiO2 coating to 83 times and 112 times, respectively. Adding SiO2 to ZrO2 coating Which led to the formation of pores in the coating, and the porosity and pore diameter increased with the increase of the amount of SiO2.3.The pores with a diameter of about 1μm were formed in the 3.0% SiO2 + ZrO2 coating with a porosity of about 10% , This time, the coating elastic modulus and stress suffered the smallest, so the thermal shock resistance of the coating is best