(中南大學(xué) 粉末冶金國家重點(diǎn)實(shí)驗(yàn)室，長沙 410083)
摘 要: 以費(fèi)氏粒度為8.06 μm 的WC粉與Co(NO3)2·6H2O為原料，采用N(CH2CH2OH)3(TEA)為還原劑制備WC-12%Co(質(zhì)量分?jǐn)?shù))包裹粉，以包裹粉為原料制備WC-12%Co硬質(zhì)合金。采用掃描電鏡觀察包裹粉與合金中WC晶粒的立體形貌，采用X射線衍射儀分析粉末的物相組成，采用比表面積分析儀分析TEA還原產(chǎn)物多孔泡沫Co的比表面積，采用金相顯微鏡觀察合金的組織結(jié)構(gòu)。結(jié)果表明：包裹粉中Co為純fcc高溫相結(jié)構(gòu)，呈多孔泡沫狀納米組裝結(jié)構(gòu)形式包裹在WC粉末表面；WC-12%Co合金組織結(jié)構(gòu)均勻，平均晶粒度為4.8 μm，WC晶粒結(jié)晶完整、呈規(guī)則多面體形狀。
關(guān)鍵字: 硬質(zhì)合金；粗晶粒WC；納米Co；泡沫Co；有機(jī)物還原
WC powders by chemical route
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（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The WC-12%Co (mass fraction) cemented carbide with an average grain size of 4.8 μm and homogeneous microstructure was prepared from porous spumous cobalt enwrapped tungsten carbide powders produced by a novel chemical route. The tungsten carbide powder with Fisher sub-sieve sizer granularity of 8.06 μm and cobaltous nitrate hexahydrate were used as the starting materials, and the triethanolamine (TEA) was used as the reducer. The phase constitutes and morphology of the powders were investigated by X-ray diffractometry and scanning electron microscopy, respectively. BET specific surface area analyzer was used to analyze the porous spumous cobalt reduced with TEA. The microstructure of WC-Co cemented carbide was observed by metallographic microscopy. The results show that, in the cobalt enwrapped WC powders, cobalt exists in pure face centered cubic structure in the form of nano particles assembly. The tungsten carbide grains in the alloy are characterized by regular polyhedron morphology and high degree of crystalline perfection.
Key words: cemented carbide; coarse WC grain; nano-sized cobalt; porous spumous cobalt; organic reduction
