SiC-TiB_2复相陶瓷的制备及其抗氧化性能研究  

Preparation and Antioxidation Performance of SiC-TiB_2 Composites

作　　者：胡继林[1] 郭文明[2] 彭红霞[1] 吴腾宴[1] 田修营[1] 

机构地区：[1]湖南人文科技学院化学与材料科学系,娄底417000 [2]湖南大学材料科学与工程学院,长沙410082

出　　处：《材料导报》2015年第22期53-56,共4页Materials Reports

基　　金：国家自然科学基金(51302076);中国博士后科学基金(2013M531783)

摘　　要：以α-SiC、B_4C、TiO_2为原料,用AlN、Y_2O_3作为烧结助剂,采用热压烧结工艺制备出SiC-TiB_2复相陶瓷样品。采用等温氧化增重法,研究原位合成的SiC-TiB_2复相陶瓷在600℃、800℃、1000℃和1200℃下的抗氧化性能。采用扫描电镜(SEM)对所制备的复相陶瓷的表面形貌进行分析,同时采用X射线衍射仪(XRD)对烧结体样品及其氧化产物的物相成分进行分析。实验结果表明,当烧结助剂的含量为15%(体积分数)时,烧结体样品气孔较少,且颗粒尺寸的均匀性较好,赋予复相陶瓷较好的致密度(相对密度达98.3%)、抗弯强度(551 MPa)和硬度(90.1HRA)。SiC-TiB_2复相陶瓷在空气中中温氧化时,其氧化行为表现为氧化增重随时间的变化服从抛物线规律。在研究的温度范围内,该复相陶瓷的氧化机理为:TiB_2优先被氧化成TiO_2和B_2O_3,然后是SiC在较高温度下被氧化成SiO_2和CO_2。SiC-TiN composites were fabricated by HP sintering with α-SiC, B4C, TiO2 as raw materials and AlN, Y2O3 as sintering aids. The oxidation behavior of SiC-TiB2 composites in-situ synthesized was studied at 600 ℃, 800 ℃, 1000℃ and 1200 ℃ by isothermal oxidation method. Scanning electron microscopy （SEM） was used to analyze the surface morphology of the composites. And X-ray diffraction （XRD） was used to analyze the phase of the sintered samples and its oxidation products. The results show that the sintered samples have few gas pores and particle uniformity and endow SiC-TiN composites with high density （relative density of 98. 3 %）, flexural strength （551 MPa） and Rockwell hardness （90. 1HRA）. The oxidation weight gain of SiC-TiB2 composites follows parabolic law as the time increases when it is oxidized in medium temperature atmosphere. The oxidation mechanism of the composites is that TiN is preferentially oxidized into TiO2 and NO3, then SiC is oxidized into SiO2 and CO2 in the range of the study temperature.

关 键 词：SiC-TiB2 复相陶瓷 抗氧化性能 氧化机理 

分 类 号：TQ174[化学工程—陶瓷工业]