超硬合金粉末のふるい工程における運転条件の最適化

抄録

Super hard alloy tools are manufactured by powder metallurgy methods. Powders of carbonized tungsten and other metal materials are obtained by wet mixing, pulverizing, and drying. These processes tend to generate aggregates and agglomerates, which must be removed by dry sifting of the powdered material. High processing speed, high yield, and high stability are important in sifting. These factors are linked directly with production costs, so there has been a need to find improved sifting conditions. Accordingly, the functionality of a dry sifter was studied, and a parameter design was simultaneously conducted to optimize the sifting conditions. The weight of the sifted powder was measured and verified by a new S/N ratio based on a chemical reaction. With this approach, however, measurement problems caused by the structure of the sifter were encountered, so a switchover was made to evaluation by the standard S/N ratio. The optimum conditions then obtained doubled the sifting speed and improved the yield by 20% in comparison with existing conditions.