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通过球磨诱导生成薄片状W晶源,再引入超细黄钨(纳米W源)、碳黑(活性碳源)、钴及适量晶粒长大抑制剂(Cr3C2)高效球磨生成含片状晶W/Co/C复合粉末,于低压真空烧结炉中在1410℃的温度下一次碳化烧结制备了片状晶强化新型结构WC-10％ Co(质量分数,下同)硬质合金,研究了20％片状W的引入对WC-10％ Co硬质合金显微组织结构和性能的影响.通过比表面测定仪和费氏粒度仪测定了粉体的比表面和粒度,用扫描电镜(SEM)观察了粉末的形貌和烧结体的显微组织结构,按硬质合金性能测试标准对WC-Co烧结体的物理和力学性能进行了测定.结果表明,碳辅助氢还原球磨诱导生成含片状晶W/Co/C复合粉末,经一次碳化烧结可制备出显微组织结构明显不同于普通合金的含片状晶新型结构WC-Co硬质合金;20％片状W粉末的引入致使合金整体晶粒尺寸偏粗,矫顽磁力偏低,但其片状晶和超细晶粒均布的组织结构,不仅能有效提高合金的硬度,还能改善合金的断裂韧性.

The WC-10％ Co (mass fraction) cemented carbides with flatter shape of WC custals were sintered at 1410 ℃ in the lowpressure vacuum sintering furnace with methods of one step carbonization and sintering using mixed precursor powders composed of ultratine yellow tungsten oxide,cobalt,carbon black and plate-like tungsten crystal seeds prepared by ball milling induction.The effects of flatter shape of tungsten 20％ (mass fraction) added on the microstructure and properties of WC-10％ Co cemented carbides were studied.The particle size and specific surface of powders were measured by Fisher sizer and specific surface equipment,the morphologies of powders and microstructures of sintered alloys were observed by scanning electronic microscope (SEM).The physical and mechanical properties of WC-10％ Co sintered composites were tested according to related material performance testing standard.The results showed that the microstructure of new cemented carbides with flatter shape of WC crystals prepared through precursor powders with flatter shape of tungsten crystal seeds produced by ball milling induction and hydrogen in-situ reduction assisted by carbon were different obviously with normal WC-Co alloy.Adding flatter shape of tungsten 20％,the WC grain size and coercive force of new cemented carbide were coarse and low,respectively,which was conducive not only to promoting the hardness,but also promoting the fracture toughness of the alloy owing to the special structure of coarse flatter shape WC grains and lots of ultrafine WC grains homogeneously embedded in cobalt binder phase.