Low-energy grain boundaries in WC-Co cemented carbides
Low-energy grain boundaries in WC-Co cemented carbides
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WC-Co 硬质合金中的低能晶界
DOI：
10.1016/j.actamat.2019.06.015
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发表时间：
2019-08-15
期刊：
影响因子：
9.4
通讯作者：
Nie, Zuoren
中科院分区：
文献类型：
--
作者：
Liu, Xingwei;Liu, Xuemei;Nie, Zuoren
研究了WC-Co硬质合金中典型低能晶界的影响因素、分布特征及演化机制。在多角度表征的基础上，分析了不同晶粒生长抑制剂对硬质合金晶粒形状长径比、WC邻接度和低能晶界分布的影响。结果表明，该合金中Sigma 2晶界的比例较高，且形貌稳定，晶粒尺寸细小，WC邻接度大。在具有各向异性表面能的硬质合金中，大长径比WC片的聚结可能形成Sigma 13a晶界。结果表明，通过匹配晶粒生长抑制剂和初始WC-Co复合粉末的烧结温度，可以调节硬质合金中低能晶界的组成和分布。(C) 2019材料学报Elsevier Ltd.出版。版权所有。
The influencing factors, distribution characteristics and evolution mechanisms of the typical low-energy grain boundaries in the WC-Co cemented carbides were demonstrated. Based on characterizations from various angles, the correlations of grain shape aspect ratio, WC contiguity and distribution of low-energy grain boundaries were analyzed for cemented carbides with addition of different grain growth inhibitors. It was found that the Sigma 2 grain boundaries have higher fraction in the cemented carbides with stable complexions, finer grain size and larger WC contiguity. The Sigma 13a grain boundaries are likely to form in the cemented carbides with anisotropic surface energy by coalescence of WC platelets with large shape aspect ratio. The results suggest that the fraction and distribution of low-energy grain boundaries in the cemented carbides can be modulated by matching grain growth inhibitor and sintering temperature of the initial WC-Co composite powder. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.