Ba_(0.25)Sr_(0.75)Al_2Si_2O_8环境障碍涂层的制备与耐水腐蚀性能研究

Fabrication and Water-vapor Corrosion Resistance of Ba_(0.25)Sr_(0.75)Al_2Si_2O_8 Environmental Barrier Coating

以2D Cf/SiC为基底材料,采用浆料刷涂工艺制得Ba0.25Sr0.75Al2Si2O8(BSAS)环境障碍涂层,并研究了未涂覆BSAS涂层(Cf/SiC)和涂覆BSAS涂层(Cf/SiC-BSAS)的两种试样的耐水腐蚀性能.结果表明:采用浆料刷涂工艺涂覆,在高纯氩气保护气氛下,经1350℃高温烧结,可在Cf/SiC试样上制得致密且无明显缺陷的BSAS涂层,一次涂覆烧结的厚度约为15μm,三次涂覆烧结涂层的厚度可达50μm;在1250℃、50%H2O-50%O2、常压静态气氛下腐蚀100h后,Cf/SiC试样的重量和抗弯强度均发生明显下降,Cf/SiC-BSAS试样的重量基本不变,强度保持率高达90%以上.

Ba0.25Sr0.75Al2Si2O8（BSAS） as environmental barrier coating（EBC） was coated on the 2D Cf/SiC substrate using slurry-brushing process.The water-vapor corrosion resistance of Cf/SiC and Cf/SiC-BSAS were studied in 50%H2O-50%O2 water vapor under atmospheric pressure and static atmosphere at 1250℃,respectively.The results show that the dense BSAS coating with free cracks can be prepared by slurry-brushing method followed by heat-treatment at 1350℃ in high purity argon.The coating thickness approximate to 15μm after pasted once,and can reach 50μm after pasted for three times.The weight and flexural strength of Cf/SiC-SiC decreases greatly,while the weight of Cf/SiC-BSAS has no obvious change and the flexural strength retention is over 90% after corroded for 100 h.