硬质合金混合料粒度分布对成型尺寸精度的影响

Influence of Particle Size Distribution of Powder Mixture on Molding Precision of Cemented Carbide

针对影响硬质合金产品成型尺寸精度的混合料压制性能参数进行分析,确认混合料粒度分布组成是关键影响因素之一。混合料粉末各级粒度分布相对均匀,能够有效提高压制过程中粉末填充的均匀性,保证压坯密度相对均匀,减小烧结后发生变形,有利于产品成型尺寸的控制。而利用双螺旋混合机采用混合料干混合合批工艺,能够有效提高混合料批次内粉末各级粒度的均匀性,缩小各级粉末质量分数极差,达到提升数控刀片成型尺寸精度的目的。

The pressing properties of powder mixture influencing the molding precision of cemented carbide were analyzed. It is confirmed that the particle size distribution of the powder mixture is one of the key influencing factors. If the particle size distribution of the powder mixture is uniform, the powder filling can be effectively improved, the density of the blank is even, the deformation after sintering is reduced, so the molding size can be effectively controlled. By using double screw mixer for dry mixing, the distribution uniformity of the particle size of the powder mixture at all level can be improved,the range of the mass fraction of the powder mixture at all levels is reduced, the molding precision of the NC blade forming is improved.