Evaluation of two-component powder mixing by vertical vibration: Investigation of powder behavior and mixed state by internal pressure fluctuation

Recently, functional materials using powder material such as fine ceramics have been developed. Evaluating the mixing process is important to these materials because mixed state of the powder greatly influences quality and function of molded product. However, the difference of powder properties (density, diameter, etc.) causes defective mixing such as segregation. The purpose of this study is, in the vertical vibration mixing of the two-component powder with the density difference, to elucidate physical phenomenon of powder such as convection and segregation, and to clarify the relation among the powder behavior, the mixed state, and the vibration condition. In this case, though pressure fluctuation in the powder bed will result from the force doing on the vessel wall (bottom and sidewall), it is difficult to understand the mixing mechanism using the fine particle because of many parameters controlling powder behavior. So, in this study, by considering the pressure fluctuation in the powder bed, influence of the powder behavior under the vertical vibration on the mixed state was investigated by using a macroscopic particle (diameter=1 mm). The two-dimensional simulation of particle element method (PEM) was done to make propose the powder mixture mechanism under the vertical vibration.