烧结温度对ZrSiO_4-Mullite复合涂层组织结构及抗氧化性能的影响

Effect of Sintering Temperature on Microstructure and Oxidation Resistance of ZrSiO_4-Mullite Multi-layer Coating

在前期研究工作基础上,借助XRD、体式显微镜等组织结构表征途径和等温氧化实验技术,系统研究了烧结温度(1500～1700℃)对ZrSiO4-Mullite涂层组织结构和抗氧化性能的影响。结果表明:不同温度下烧制的涂层均由ZrSiO4、Mullite和ZrO2三种物相构成。烧结温度提高,涂层内的Mullite相含量增大、ZrSiO4和ZrO2含量减少,而涂层缺陷数量则先减后增。1600℃下烧制的ZrSiO4-Mullite复合涂层致密、完整,涂层缺陷少,抗氧化性能最佳。同时,提高烧结温度有利于改善ZrSiO4-Mullite复合涂层内的层间结合,增强涂层的抗热震能力。

Based on the results of previous study, the effect of sintering temperatures （1500-1700 ℃） on microstructure and oxidation resistance of ZrSiO4-Mullite multi-layer coated C/C composites was investigated respectively. The as-prepared multi-layer coatings with different sintering temperatures were characterized by XRD and optical microscope analysis. Oxidation resistance of multi-coatings was measured through isothermal oxidation tests. The results indicated that the multi-coating was composed of ZrSiO4, Mullite and ZrO2. With temperature enhancement, the content of mullite was increased, however, ZrSiO4 content and ZrO2 content were all decreased. The content of coating defects was decreased first and increased later with temperature development. The ZrSiO4-Mullite multi-layer coating prepared at 1600℃ had good oxidation resistance, because it was dense and integral, synchronously, had low defect content. Additionally, temperature improvement was benefit to improve the interfacial bonding and the thermal shock resistance of ZrSiO4-Mullite multi-layer coating.