Mixing Torque Measurement - an Effective Tool for Identifying Critical Binder Volume Concentrations for Ceramic Processing

Abstract

Ceramic processing of powders, mixed with additives, can be classified into three regimes: CBVC [Critical Binder Volume Concentration], sub CBVC and post CBVC which correspond to viscous plastic processing, compaction processing and colloidal processing respectively. These regimes can be estimated experimentally by measuring the mixing torque for different ratios of the powder to additive concentration. In the present study, the torque required for mixing is indirectly estimated by measuring the torque of the AC motor that drives the blender. Analysis of the Torque v/s Volume Concentration curve permits delineation of the three zones. Our present study was carried out using alumina powder mixed with a binder. The developed torque was logged in a paperless chart recorder, with built-in storage memory.