等离子喷涂SiO2+ZrO2涂层的抗热震性能
来源期刊：中南大学学报(自然科学版)2001年第1期
论文作者：唐建成 邵德春 郭面焕 黄伯云 周科朝
文章页码：62 - 65
关键词：等离子喷涂; SiO2添加剂;抗热震;气孔
Key words：plasma-spray; additive SiO2; thermal shock resistance; gas cavity
摘 要：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.
Abstract: In order to improve the thermal shock resistance of plasma-sprayed ZrO2 coating, the effect of additive SiO2 on its micro structures and thermal shock resistance was investigated by means of SEM, EPMA and thermal shock tests.When the mass fraction of additive SiO2 is less than 3.0%, the thermal shock resistance of coating increases with the increase of the mass fraction of additive SiO2. But when it is more than 3.0%, the thermal shock resistance decreases with its increase. The lifetimes of fracture initiation and fracture failure of the coating with 3.0% SiO2 reach the maximum values, and they increase from 32 and 46 cycles to 83 and 112 cycles respectively, compared with the values of the coating without SiO2. Adding SiO2 results in the formation of gas cavities in coating, and the proportions and sizes of gas cavities increase with increasing mass fraction of additive SiO2. The gas cavities of about1μmarewell distributed in ZrO2+3.0%SiO2 coating and the proportion is about 10%. This pattern of gas cavity decreases the elastic module to the minimum. The residual stress and thermal stress of coating reach the minimum because they decrease with the decrease of the elastic module, so the thermal shock resistance of 3.0%SiO2+ZrO2 coating reaches the maximum value.
