INVESTIGATION OF COMPACTION EQUATIONS FOR POWDERS

Two compaction equations (isothermal equations of state) for powders w ere developed, and experimemts on the compaction of various ceramic po wders were designed to examine these equations. A nonlinear least-squa res technique was utilized to evaluate these and other published compa ction equations for press compaction of submicrometer and nanosize pow ders. A modified linear least-squares method was developed for fitting experimental data to one of the present equations. The root-mean-squa re deviation per degree of freedom (rms) for fitting compaction data o f powders using the present equations was reduced by almost one order of magnitude by comparison with fitting to that of Cooper and Eaton's equation. Data analysis indicates that our equations yield better fitt ing of data than the previous equations, and these equations can be ap plied to chemically different powders, powders with different size dis tribution of particles.