Effects of Ball Size and Particle Size on the Rate of Wet Ball-Milling

Abstract

A lead-based relaxor material for multilayer ceramic capacitors was ground by ball-milling with partially stabilized zirconia balls of 1, 3 and 15mm in diameter and the effects of ball size and particle size of powder on milling rate were studied. Particle size distribution and specific surface area of powders were examined as a function of grinding time. Small zirconia balls in ball milling were effective to grind the powder to submicronmeter. In order to explain these experimental results on the milling rate, an equation for expressing the milling rate was proposed. The new equation is characterized by two parameters, ball size and particle size of the powder. The calculated and observed milling rates agreed well, and the effects of ball size and particle size on the milling rate were quantitatively confirmed It was found by estimating the proposed equation that milling rate of a powder had a maximum value at a ball size. Tha ball size which showed the maximum milling rate increased as particle size and mechanical strength of the powder increased.