The present study was concerned with the high temperature sintering behaviour of zirconium diboride ceramics mixed with fine silicon carbide. Zirconium diboride-silicon carbide (ZrB2-SiC) ceramic composites were pressureless sintered at 2100 °C under flowing argon environment, for a hold time of 150 min. The pressureless sintered ZrB2-SiC pellets were characterized for microstructure and phase analysis. The sintered microstructure was observed through Scanning Electron Microscopy (SEM) embedded with Energy Dispersive Spectroscopy (EDS) and different phases were analyzed through X-ray Diffraction (XRD). The investigation revealed the presence of boron carbide (B4C) within the sintered pellets containing 20 mol.% SiC. The B4C was formed during sintering without the presence of any free carbon as part of initial powder mixture. Possible routes to identify and explain the formation of B4C in the absence of free carbon were discussed. © 2017 Elsevier B.V.

中文翻译：

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在 2100 °C 下对烧结 ZrB 2 -SiC 陶瓷复合材料中 B 4 C 形成的评估

本研究涉及混合有细碳化硅的二硼化锆陶瓷的高温烧结行为。二硼化锆-碳化硅 (ZrB2-SiC) 陶瓷复合材料在 2100 °C 的流动氩气环境下无压烧结，保温时间为 150 分钟。对无压烧结 ZrB2-SiC 球团进行微观结构和相分析表征。通过嵌入能量色散光谱 (EDS) 的扫描电子显微镜 (SEM) 观察烧结微观结构，并通过 X 射线衍射 (XRD) 分析不同的相。调查表明，在含有 20 mol.% SiC 的烧结球团中存在碳化硼 (B4C)。B4C 是在烧结过程中形成的，不存在任何游离碳作为初始粉末混合物的一部分。讨论了在没有游离碳的情况下识别和解释 B4C 形成的可能途径。© 2017 Elsevier BV