【摘要】 以Si3N4,Al2O3,SiC及少量SiO2为原料,研究Al2O3-SiC-Si3N4复相材料在埋炭条件下的反应烧结过程,并借助SEM,EDX和XRD对其微观结构和物相变化进行了分析。研究结果表明,活性α-Al2O3和纳米SiO2能够促进Al2O3-SiC-Si3N4复相材料的烧结,体积密度提高,显气孔率降低,从而提高了强度。在复相材料的合成过程中,发现在高温下烧成的试样内有Sialon相和Si2N2O相生成。更多还原

【Abstract】 Using Si₃N₄,Al₂O₃,SiC and SiO₂ as raw materials,the sintering process of Al₂O₃-SiC-Si₃N₄ composites is studied at reduction atmosphere and the microstructure and phase change of the composites are analyzed by means of SEM,EDX and XRD . The results show that active α-Al₂O₃ powder and nanometer-SiO₂ can promote the sintering property of Al₂O₃-Si-Si₃N₄ composites and a ceruain amount of Sialon phase and Si₂N₂O phase are produced under high temperature.It is also found that both α-Al₂O₃ powder and nanometer-SiO₂ can improve volume density and reduce the apparent porosity of the samples, thereby improving the strength of samples.更多还原