ABSTRACT

Slurry impregnation and gaseous Si infiltration were effectively used to produce compact MoSi₂-doped Si–HfB₂–SiC/Si–SiC (HMSS/SS) coatings with a thickness of 250 μm to protect carbon fibre reinforced carbon (C_f/C) composites from oxygen corrosion at 1700°C. The HMSS/SS coating obtained with a mosaic structure makes it possible to protect C_f/C composites at 1700°C for 276 h and the mass reduction is only 0.99%. The pinning effect of the embedded hafnia, the generated MoB together with the Hf, Mo co-doped Si-based glass layer, which successfully prevented the migration of oxygen, was attributed to the superior oxidation protection ability of the HMSS/SS coatings. This work provides a practical method for successfully extending the service life of C_f/C composites in the aerospace industry.

摘要

浆料浸渍和气态硅渗透可有效生产厚度为250μm的致密MoSi ₂掺杂Si–HfB _{2 –SiC/Si–SiC (HMSS/SS)涂层，以保护碳纤维增强碳(C f} /C)复合材料在 1700°C 下免受氧腐蚀。通过镶嵌结构获得的 HMSS/SS 涂层可以保护 C _f/C复合材料在1700℃下保温276小时，质量减少仅为0.99%。嵌入的二氧化铪、生成的MoB与Hf、Mo共掺杂的硅基玻璃层的钉扎效应成功地阻止了氧的迁移，这归因于HMSS/SS涂层优异的氧化防护能力。这项工作为成功延长航空航天工业中C _f /C复合材料的使用寿命提供了一种实用方法。