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Al2O3/SiC复合物中含有不同体积分数(3%、5%、10%、15%和20%)的SiC颗粒,该复合物通过混合氧化铝和碳化硅粉末,在1 740℃、30MPa下Ar气气氛中热压1h制备而成。本文研究了SiC体积分数对复合物显微结构和蠕变性能的影响,并讨论了可能的蠕变机制。研究了复合物在高达1 350℃下的蠕变性能以及200MPa下的机械载荷,以及曾经报道过的更为苛刻条件下的上述性能,并将其与块状Al2O3参照物相比较。Al2O3/SiC显微复合物的显微结构和蠕变性能明显受到了SiC微粒体积分数和氧化铝基质平均粒度的影响。相比块状Al2O3,Al2O3/SiC复合物的抗蠕变性显著提高,特别是材料中含有10%(体积)SiC时。机械损坏前经历很长的加载时间暗示了颗粒晶界滑动和气蚀所控制的蠕变行为。抗蠕变性增强是由于晶粒边界被晶间纳米SiC颗粒所钉扎。
The Al2O3 / SiC composites contain SiC particles with different volume fractions (3%, 5%, 10%, 15% and 20%) by mixing alumina and silicon carbide powders at 1 740 ℃ and 30MPa for Ar Gas atmosphere hot 1h prepared. In this paper, the influence of SiC volume fraction on the microstructure and creep properties of the composites was investigated and the possible creep mechanism was discussed. The creep properties of the composites at up to 1 350 ° C and the mechanical loading at 200 MPa, as well as the above-mentioned properties under more severe conditions reported previously, were investigated and compared with bulk Al 2 O 3 references. The microstructure and creep properties of the Al2O3 / SiC microstructures are significantly affected by the SiC particle volume fraction and the average particle size of the alumina matrix. The creep resistance of the Al 2 O 3 / SiC composites is significantly higher than bulk Al 2 O 3, especially when the material contains 10% SiC by volume. The long loading time before mechanical failure implies creep behavior controlled by grain boundary sliding and cavitation. The creep resistance is enhanced because the grain boundaries are pinned by intergranular nano-SiC particles.