等离子喷涂BSAS环境障涂层性能研究

Study on the Properties of BSAS Environmental Barrier Coatings by Atmospheric Plasma Spraying

采用等离子喷涂工艺在SiC陶瓷表面制备了BSAS环境障涂层,分析研究了环境障涂层的微观结构、结合强度、长期抗氧化性能、抗热震性能和抗高温水氧腐蚀性能。结果表明:BSAS环境障涂层的结合强度为29 MPa,内部结构均匀,无贯穿裂纹和连通气孔;涂层热震30次开始有微裂纹,热震50次后出现贯穿裂纹失效;涂层于空气中1 200℃/200 h氧化后增重0.24%,内部氧化不明显;在1 atm、1 200℃、50%H_2O-50%O_2、0.4 m/s高温水氧环境中腐蚀150 h后,涂层保护试样失重0.87 mg/cm2,涂层表面腐蚀厚度小于10μm,无涂层保护的试样失重3.4 mg/cm^2。

BSAS environmental barrier coatings on SiC substrate were fabricated by atmospheric plasma spraying. The microstrueture, cohesive strength, long-term oxidation resistance, thermal shock resistance and corrosion resistance of the coating were analyzed. Results show that BSAS environmental barrier coatings have a uniform structure with few pores and no cracks, with the cohesive strength of 29 MPa. Microcracks appear at the 30th thermal shock, and the coatings are failed after 50th thermal shock. Mass change of the SiC-Si/BSAS coating is 0.24% oxidized at 1 200℃ for 200 hours, and internal oxidation is not obvious. After a 150 h exposure at 1 200℃ in 1 atm, 50% H2O-50%O2, 0. 4 m/s environment, mass change of SiC-Si/BSAS coating is -0. 87 mg/cm^2, with the corrosion depth less than 10μm, while the mass change of uncoated SiC is -3.4 mg/cm^2.