ASPECTS OF EROSIONAL WEAR BEHAVIOR DURING TUMBLING OF BATIO3 DIELECTRIC CERAMICS

Erosional wear by tumbling is a necessary step in shaping and surface finishing before the application of metallic end-termination in the manufacture of millimeter-sized, brick-shaped ceramic multilayer capacitors (CMC). The geometric parameters corner radius R (mu-m) and aspect ratio A/d of the CMC products were evaluated with respect to shaping and erosion rates. A shaping index n was introduced to indicate the shaping rate given by the ratio d(log R)/d(log time). For a particular hot-pressed CMC product type there was a direct correlation between A/d and n. The calculated tumbling time t(c) in minutes plotted against A/d for different corner radii (R = 30, 50, 70, 90-mu-m) appears to be a useful guide for indicating the effect of the aspect ratio on the shaping or relative erosion rates for the target corner radii of the finished products. The effect of different material processing may also be revealed.