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采用16Si-x Al-4NH4F-Bal.Al_2O_3(x=1,2,3,4,%,质量分数)渗剂经1200℃扩散共渗5 h在Mo表面制备了不同Al含量的Mo(Si,Al)_2涂层,分析了渗剂中Al含量对涂层组织及其氧化膜结构的影响。结果表明,不同渗剂所形成涂层均具有多层结构,涂层的外层均由Mo(Si,Al)_2相组成;渗剂Al含量为1和2%时,涂层中间层均为Mo_5(Si,Al)_3相,内层则分别为固溶有少量Al的Mo或Mo_3(Al,Si)相;渗剂Al含量为3和4%时,涂层中间层均由Mo5(Si,Al)_3和Mo_3Al_8相组成,内层则均为Mo_3(Al,Si)相。对含Al为1和4%的渗剂所制备的涂层在1250℃下氧化50 h,前者氧化膜厚度约为3μm,主要由SiO_2组成;后者氧化膜厚度约为10μm,上部由Al_2O_3和SiO_2的混合物组成,下部为Al_2O_3。
Al (superscript 2 +), Si (superscript 3 +), Al (superscript 3 +), Mo (Si, Al) _2 coating, the effect of Al content in the penetration agent on the microstructure and oxide film structure of the coating was analyzed. The results show that the coatings formed by different penetration agents all have a multi-layer structure, the outer layer of the coating is composed of Mo (Si, Al) _2 phase; when the Al content of penetration agent is 1 and 2% Mo_5 (Si, Al) _3 phase, and the inner layers are respectively Mo or Mo_3 (Al, Si) phase with a small amount of Al solid solution; when the Al content is 3 and 4% , Al) _3 and Mo_3Al_8 phase, the inner layer is Mo_3 (Al, Si) phase. The coatings prepared with 1% and 4% Al infiltration agent were oxidized at 1250 ℃ for 50 h. The former oxide film thickness was about 3 μm and consisted mainly of SiO 2. The latter oxide film thickness was about 10 μm. The upper layer consisted of Al 2 O 3 and SiO 2 mixture, the lower part of Al 2 O 3.