National Key Laboratory of Advanced Composites, Beijing Institute of Aeronautical Materials, Aviation Industry Corporation of China Composites Center,
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DOI:
10.7502/j.issn.1674-3962.2016.06.11
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Abstract:
BSAS environmental barrier coatings on SiC substrate were fabricated by atmospheric plasma spraying. The microstructure, cohesive strength, longterm 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 shocks, and the coatings are failed after 50th thermal shocks. Mass change of the SiCSi/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 SiCSi/BSAS coating is -0.87 mg/cm2, with the corrosion depth less than10 μm, while the mass change of uncoated SiC is -3.4 mg/cm2.