Preparation and Characterization of Rod-Like β-Si3N4 Seeds
Preparation and Characterization of Rod-Like β-Si3N4 Seeds
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DOI：
10.4028/www.scientific.net/kem.280-283.1223
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发表时间：
2004-12
期刊：
影响因子：
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通讯作者：
J. Yang;Bo Wang;J. Gao;Jian Feng Yang;Guanhao Qiao;Hong Jie Wang;Z. Jin
中科院分区：
文献类型：
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作者：
J. Yang;Bo Wang;J. Gao;Jian Feng Yang;Guanhao Qiao;Hong Jie Wang;Z. Jin
本文的目的是展示一种制备棒状β-Si3N4种子用于自增强氮化硅陶瓷的方法。将含有不同含量的β-Si3N4粉末的α-Si3N4与一定的添加剂在1800°С下加热，在0.5MPa氮气下保温不同时间，得到了不同尺寸和纵横比的β-Si3N4种子。采用扫描电镜（SEM）和x射线衍射（XRD）对其形貌、相变和二次相进行了研究。研究了α-Si3N4初始粉末中β-Si3N4的比例对种子大小和形态的影响。通过添加β-Si3N4获得均匀的、尺寸和长径比可控的β-Si3N4种子，这可以解释为增加了非均相成核，MgO通过降低粘度更有效地促进了晶粒的生长。
The purpose of this paper is to demonstrate a method of preparation of rod-like β-Si3N4 seeds for self-reinforced silicon nitride ceramics. β-Si3N4 seeds with different size and aspect ratios have been well developed by means of heating the mixture of α-Si3N4 containing various contents of β-Si3N4 powder with certain additives at 1800°С for holding different time under 0.5MPa nitrogen gas. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were performed to investigate the morphology, phase transformation and secondary phase. The influence of the proportion of β-Si3N4 in the initial α-Si3N4 powder on seeds size and morphology was investigated. The uniform β-Si3N4 seeds with controllable size and aspect ratios obtained through the β-Si3N4 addition can be explained by an increased heterogeneous nucleation, and MgO was more effective for enhancing the grain growth by the decreased viscosity.