【摘要】 利用X-射线衍射仪、扫描电镜和热重分析仪等手段,在1100～1500℃研究了Sialon结合SiC复相材料的高温抗氧化行为。结果表明:随氧化温度升高,由于氧化致密层的形成,试样氧化增重速率降低,出现氧化钝化现象;Sialon结合SiC复相材料高温抗氧化性能优于Si3N4结合SiC复相材料;高温氧化使得SiC质复相材料常温抗压强度比氧化前提高;随氧化温度升高,Sialon结合SiC复相材料的氧化膜表面形成较多气泡和开口空洞,使耐压强度呈下降趋势;Si3N4结合SiC复相材料随氧化温度升高,耐压强度降低,这是由于冷却过程方石英化伴生的网状裂纹密度增大。更多还原

【Abstract】 The high temperature oxidation behavior of two kinds of SiC-based multiphase material was investigated at 1100～1500 ℃ by X-ray diffractometer,scanning electronic microscopy and thermogravimetry.The results show that: the oxidation mass increment rate of the sample decreases with increasing oxidation temperature due to the formation of dense oxidation layer.The oxidation passivation occurs with the increase of oxidation temperature.The oxidation resistance of Sialon-bonded SiC multiphase material is superior to that of Si3N4-bonded SiC multiphase material.The high temperature oxidation results in the increase of compressive strength at room temperature of SiC-based multiphase material compared with unoxidized sample.The compressive strength of Sialon-bonded SiC samples oxidized at high temperature decreases with the increase of oxidation temperature as a result of formation and burst of surface bubble.While the decrease of compressive strength of Si3N4-bonded SiC samples oxidized at high temperature can contribute to the increase of the consistency of net-like crack associating with cristobalite transformation during cooling.更多还原