碳化钨粉分级对粉末特性与合金性能的影响

Effect of Tungsten Carbide Powder Grading on Powder Characteristics and Alloy Properties

对市售16μmWC进行风力分级,得到了粗中细三种粒级的粉末,分析了原粉、分级粉的供应态和研磨态费氏粒度、粒度分布等特性,比较了用4种粉末制备的WC-10%Co的合金特性。结果表明:分级粉的均匀性都有改善;粗粉费氏粒度是细粉的2倍,研磨态粒度则相差很小;粉末的碳含量是随分级粉粒度变小而增高。4种粉末制备的合金的密度、硬度、磁力、钴磁差别不大,分级粉的抗弯强度则随着粒度变细而提高,Fsss供/Fsss研的值越小,合金强度越高,比值为3.1的细粉制备的合金的抗弯强度比其值为6.2的粗粉合金的抗弯强度提高29%,且金相组织中的WC和Co相最为均匀。

The commercially available coarse tungsten carbide powder was graded,and powders with three kinds of particle sizes were obtained.Powder characteristics of the original and the graded powders at supply state and grinded state were analysized.Properties of WC-10%Co alloy prepared by the four kinds of powders were compared.Results show that after grading,the homogeneity of coarse,medium and fine tungsten carbide is improved.Coarse powder’s Fsss is two times of fine powder’s Fsss.After grinding,the difference becomes very small.Carbon content increases with the finer of the particle size of graded powder.There are little differences between the density,hardness,magnetism and magnetic cobalt of cemented carbides prepared by the four kinds of powders.The flexural strength of the alloy prepared by graded powder improves with the finer of the particle size.The smaller the Fssssupply/Fsssgrinded value,the higher the strength of the alloy.The flexural strength of cemented carbide prepared by fine powder with Fssssupply/Fsssgrinded value of 3.2 is 29% higher than that of alloy prepared by coarse powder with the value of 6.2.And the distributions of WC and Co phase are more uniform.