APT形貌对W、WC粉及硬质合金组织性能的影响研究

Effect of Morphology of APT on Microstructure and Properties of W,WC Powder and Cemented Carbide

采用不同结晶工艺制备的单晶APT以及多晶APT为原料,经高温煅烧后制得单晶三氧化钨以及多晶三氧化钨。然后以单晶三氧化钨和多晶三氧化钨为原料,制备了中颗粒钨粉、碳化钨及WC-6%Co硬质合金,并详细研究了APT形貌对粉末产品和硬质合金微观组织和物理力学性能的影响。结果表明:不同形貌的APT经煅烧后制备的三氧化钨仍保留APT的形貌。两种不同形貌三氧化钨制备的钨粉均呈类球形,但单晶三氧化钨制备的钨粉均匀性好,细粉少,晶粒无明显晶体学平面,球化程度高;而多晶三氧化钨制备的钨粉均匀性较差,细粉含量偏多,晶粒具有明显晶体学平面。在碳化过程中单晶三氧化钨制备的钨粉粒度涨幅为21.5%,显著高于多晶三氧化钨制备的钨粉,且所制碳化钨中球化程度高的颗粒更多。相比于以多晶APT为原料制备的WC-6%Co硬质合金,以单晶APT为原料制备的WC-6%Co硬质合金矫顽磁力、硬度及抗弯强度更高,微观组织均匀性更好,合金整体性能更优。

Single crystal APT and polycrystalline APT prepared by different crystallization processes were used as raw materials to produce single crystal tungsten trioxide and polycrystalline tungsten trioxide after high temperature calcination.Then, using single crystal tungsten trioxide and polycrystal tungsten trioxide as raw materials, medium grain tungsten powder, tungsten carbide and WC-6%Co cemented carbide were prepared, and the effect of APT morphology on the microstructure, physical and mechanical properties of powder products and cemented carbide were studied in detail.The results show that the tungsten trioxide prepared by calcining APT with different morphologies still retains the morphology of APT.The tungsten powder prepared by two kinds of tungsten trioxide with different morphologies is quasi-spherical, but the tungsten powder prepared by single crystal tungsten trioxide has good uniformity, less fine powder, no obvious crystallographic plane and high spheroidization degree.However, the tungsten powder prepared by polycrystalline tungsten trioxide has poor uniformity, more fine powder and obvious crystallographic plane.In the carbonization process, the grain size of tungsten powder prepared by single crystal tungsten trioxide increases by 21.5%,which is significantly higher compared with tungsten powder prepared by polycrystalline tungsten trioxide, and the granules with high spheroidization degree are more in the prepared tungsten carbide.Compared with WC-6%Co cemented carbide prepared by polycrystalline APT,WC-6%Co cemented carbide prepared by single crystal APT has higher coercive force, hardness and bending strength, better microstructure uniformity and more excellent overall properties.