Microstructure and mechanical properties of hot-pressed WC-MgO composites with Cr₃C₂ or VC addition

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• 作者：Chenxin Ouyang ; Shigen Zhu ; Weiwei Dong ; Haixia Qu
• 关键词：Grain growth inhibitors ; Tungsten carbide ; Magnesium oxide ; Sintering
• 刊名：International Journal of Refractory Metals and Hard Materials
• 出版年：2013
• 出版时间：November, 2013
• 年：2013
• 卷：41
• 期：Complete
• 页码：41-47
• 全文大小：1455 K

文摘

The influence of Cr₃C₂ and VC addition on the microstructure and mechanical properties of WC-MgO composites hot-pressed at 1650 ¡ãC for 90 min was comprehensively investigated. The grain growth of WC was significantly retarded and the homogeneity of MgO particulate dispersion was effectively improved with the addition of 0.5 wt. % Cr₃C₂ or 0.5 wt. % VC. The indentation size effect (ISE) on hardness was restrained and the load-independent hardness was increased by doping grain growth inhibitors. Improvements on fracture toughness of hot-pressed samples were also observed due to the refined WC grains and uniformly dispersed MgO particulates. In addition, experimental results demonstrated that Niihara's equation was preferable for estimating the indentation fracture toughness, by comparing the fracture toughness evaluated using the single-edge V-notch beam (SEVNB) method with the values estimated through the Vickers indentation technique.