Preparation of La-monazite fiber coating on quartz fiber fabric by a repeated dip-sintering method

Abstract

In order to prevent the embrittlement of high emissivity coating coated quartz fiber fabric applied in Thermal Protection System, LaPO4 fiber coating was prepared on the fiber fabric by a repeated dip-sintering method using a liquid precursor. The formation process of La-monazite from the precursor was investigated, and on this basis, a high-temperature and short-time sintering schedule (1200 °C/60 s) was determined. Pure La-monazite fiber coating with a thickness of 80–300 nm was obtained, and cristobalite crystallization in the fibers was avoided. The La-monazite coated quartz fiber fabric retained the flexibility of the original quartz fiber fabric. By precoating La-monazite fiber coating, the quartz fiber fabric coated with SiC–SiO2 high emissivity coating showed significantly increased ultimate bending deflection in three-point bending test, and fiber pull out and fabric distortion were observed at the fracture surface.