Ma Bao-Xia, Wang Yang, Zhao Si-Cong, Wu Hao-Nan, Qiao Yang
Department of Materials Science and Chemical Engineering, Harbin University of Science and Technology, Harbin 150040, China.
Materials (Basel). 2022 Mar 17;15(6):2217. doi: 10.3390/ma15062217.
In situ synthesis feasibility of ZrB-SiC-ZrC composite coatings on ZrC ceramics by reactive plasma spraying (RPS) was investigated. To help to understand the phase evolution during plasma spraying process, reaction behavior in the ZrH-Si-BC system was explored carefully by differential scanning calorimetry. The results indicated that the phase transformation sequence in the ZrH-Si-BC system could be described as ZrH, ZrO, ZrC, ZrB, ZrSi, ZrSi, and SiC. The prior formation of ZrC was due to high diffusion rate of C atoms from BC. ZrB was produced above 1100 °C. As the temperature increased, SiC were finally formed by the reaction of ZrC with ZrSi and BC. The RPS composite coatings mainly consisted of ZrB, SiC, and ZrC phases, except for a small fraction of ZrO phase. The microstructural characterization exhibited more dense melted splats, which appears to increase gradually with the increase in spraying currents and distances. The coatings had typical lamellar structure and adhered to the substrate well. The microhardness values were higher than 1000 HV, but there were few variations with varying spraying currents and distances.
研究了通过反应等离子喷涂（RPS）在ZrC陶瓷上原位合成ZrB-SiC-ZrC复合涂层的可行性。为了有助于理解等离子喷涂过程中的相演变，通过差示扫描量热法仔细研究了ZrH-Si-BC体系中的反应行为。结果表明，ZrH-Si-BC体系中的相变顺序可描述为ZrH、ZrO、ZrC、ZrB、ZrSi、ZrSi和SiC。ZrC的优先形成是由于C原子从BC中的高扩散速率。ZrB在1100℃以上生成。随着温度升高，ZrC与ZrSi和BC反应最终形成SiC。RPS复合涂层主要由ZrB、SiC和ZrC相组成，除了一小部分ZrO相。微观结构表征显示出更致密的熔融薄片，其似乎随着喷涂电流和距离的增加而逐渐增加。涂层具有典型的层状结构，并且与基体结合良好。显微硬度值高于1000 HV，但随着喷涂电流和距离的变化几乎没有变化。
