钴粉粒度对超细硬质合金性能的影响

目前在硬质合金领域,钴粉是硬质合金最佳的粘结剂,钴粉性能对合金性能有一定的影响,但研究钴粉性能对硬质合金性能及结构影响的论文较少。实验选取了从0.78～4.61μm不同粒度级别的钴粉,按YF06合金牌号配料,从压坯压力、压坯中钴粉分布以及合金的物理性能和金相组织结构等方面探讨了钴粉粒度对超细硬质合金性能及结构的影响。结果表明:随着钴粉粒度增粗,压坯的压制压力增大,但钴粉粒度对超细混合料压坯中的整体钴分布影响不明显;粒度1.0～1.5μm钴粉比其他粒度级别的钴粉制备的超细硬质合金的整体物理性能更佳;钴粉粒度对超细硬质合金的组织结构也有一定的影响,大于3μm的粗钴粉容易造成超细合金中出现钴池,钴粉太细有则可能造成钴相分布不均。

Effects of Cobalt Powder Particle Size on Properties of Ultrafine Cemented Carbide

For cemented carbide,cobalt powder is the best binder and its properties affect the properties of the alloy to a certain extent,but there are few researches concerning the effects of cobalt powder on the properties and microstructure of cemented carbide.In this study,different grades of cobalt powder with the particle size from 0.78 ～ 4.61 μm are selected.The influences of the cobalt powder particle size on the properties and microstructure of YF06 ultrafine cemented carbide are discussed in respect of the compacting pressure and cobalt powder distribution in the compact.The results show that the compacting pressure for the compact increases with the increasing of cobalt powder particle size,but the effect of cobalt powder particle size on the overall distribution of cobalt in ultrafine compact are not obvious.Overall physical properties of the ultrafine cemented carbide prepared by the cobalt powder with particle size of 1.0 ～ 1.5 μm are better than those prepared by other grades.Cobalt powder particle size also affects the structure of ultrafine cemented carbide to a certain extent.The coarse cobalt powder with the particle size of larger than 3 μm may easily cause cobalt pool in ultrafine cemented carbide,but too fine cobalt powder may cause non-uniform distribution of cobalt phase.