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制备了Ｂ_４Ｃ－ＳｉＣ／Ｃ复合材料，对不同组成的复合材料在２０１５００℃升温氧化过程进行了ＴＧ／ＤＴＡ（热重和差热联用）分析。结果表明，复合材料具有不同的高温抗氧化性能，此差异可归因于以下几方面：复合材料的组成不同（包括陶瓷粒子的种类、含量），不同种类的陶瓷粒子氧化转变成陶瓷氧化物的温度、速率不同，生成的陶瓷氧化物在高温下的物性（对基体材料的润湿性、粘度及流动性、挥发性和对氧的扩散系数等）不同。通过在炭基体中弥散Ｂ４Ｃ粒子可明显提高炭基体在８５０℃以下的抗氧化性。当复合材料中Ｂ４Ｃ含量较高而ＳｉＣ含量低时，样品表面将趋于形成Ｂ２Ｏ３较为富集的硼硅酸玻璃相，在１５００℃以下具有良好的氧化防护效果；当样品中ＳｉＣ含量较高时，在高温下（＞１２００℃），随着部分Ｂ２Ｏ３的挥发和大量ＳｉＯ２的生成，样品表面将趋于形成ＳｉＯ２较为富集的硼硅酸盐玻璃相，在高达１４００℃以上仍具有良好的氧化防护效果
The B_4C-SiC / C composites were prepared and the TG / DTA (thermogravimetry and differential thermal analysis) of the composites with different compositions at 201500 ℃ were carried out. The results show that the composites have different high temperature oxidation resistance, the difference can be attributed to the following aspects: the composition of the composite materials (including the type and content of ceramic particles), different types of ceramic particles oxidized into ceramic oxides Temperature and rate are different, the properties of the resulting ceramic oxide at high temperatures (wettability, viscosity and fluidity to the base material, volatility, diffusion coefficient to oxygen, etc.) differ. By dispersing B4C particles in the carbon matrix, the oxidation resistance of the carbon matrix below 850 ° C can be significantly improved. When the content of B4C in the composite is high and the content of SiC is low, the surface of the sample tends to form a borosilicate glass phase which is relatively rich in B2O3 and has good oxidation protection effect below 1500 ° C. When the content of SiC in the sample is relatively high At high temperatures (> 1200 ° C), the sample surface tends to form a more abundant borosilicate glass phase with increasing B 2 O 3 volatilization and bulk SiO 2 formation, with good oxidation up to 1400 ° C Protective effect