Preparation of multi-phase composite of tungsten carbide, tungsten boride and carbon by arc plasma melting: characterization of melt-cast product

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• 作者：T. Dash ; ^{tapanphy@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; B.B. Nayak ^{bbnayak@immt.res.in" class="auth_mail" title="E-mail the corresponding author bijannayak@gmail.com" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Arc plasma ; Tungsten carbide ; Boron carbide ; Tungsten boride
• 刊名：Ceramics International
• 出版年：2016
• 出版时间：January 2016
• 年：2016
• 卷：42
• 期：1
• 页码：445-459
• 全文大小：9434 K

文摘

Arc plasma melting of WC+B₄C followed by an in situ furnace cooling produced a multi-phase composite consisting of tungsten carbide, tungsten boride and carbon. The melt-cast product was prepared in six different compositions by varying the boron carbide content (within 1–15 wt%) at the charge stage. XRD, SAED and XPS characterizations of the product showed the major phases to constitute of W₂B, WB, W₂B₅ (WB₂), WC, W₂C and C. Carbon was found to exist in three different forms, such as graphite, diamond / DLC and nanocrystalline diamond (C–C sp³ coordination). FESEM, TEM and BET studies revealed the surface morphology, microstructure and non-porous nature of the composites respectively. From micro Raman spectra it was evident that W₂C and all tungsten boride phases were non-Raman active with 514 nm radiation (Ar⁺ laser). Preliminary mechanical characterization of the polished composite samples (in solid forms) showed the hardness to increase with increase in B₄C content (range: 1–10 wt%). An extraordinary hardness of 3835±80 VHN with corresponding Young’s modulus of 695±33 GPa was observed for the typical composition of WC+10 wt% B₄C. However, the hardness showed decreased value for 15 wt% B₄C added sample.