PREPARATION AND CHARACTERIZATION OF MAGNESIUM-SILICON BASED OXIDE COATING ON HIGH-CRYSTALLINE SiC FIBER AS AN INTERPHASE IN SiC/SiC COMPOSITE

摘要

Mg-Si-O coating on the advanced SiC fibers as an interphase of SiC/SiC composites was prepared by the alkoxide method.Almost all fiber surface was coated completely by 5 times dipping into the coating solution of [Mg]T = 0.50 mol/dm 3 and [Si]T=0.25 mol/dm 3 .The phases of the coating were a mixture of MgO,MgSiO3,Mg2SiO4 and SiO2 up to 1400 °C in air.The tensile strengths of the coated fibers were retained those of as-received fiber below 1400 °C,while those were slightly degraded at 1400 °C.