Derivation, testing and application of a practical compaction equation for cold die-compacted metal powders

Derivation, validity testing and usage in practice of the powder compaction Eq. P=P0.exp(−K.pn) is presented. P is the porosity at pressure p, P0 the porosity at p=0, parameters K and n represent the synergistically acting compaction parameters. The relationship between K and n, ln(K)=1.2952–7.3349.n or K=3.6517.exp(−7.3349.n), was found on the basis of cold die-compaction testing of 205 various metal powder mixes. This analysis enables calculation of additional criteria characterizing the compressibility of various metal powders. To facilitate the analysis, a graphical processing of the relationship between the relative porosity P/P0 of the compact, p and n is also presented. In practice, its use could provide a rapid assessment of the compressibility behaviour of various metal powders. [Display omitted] •Cold die-compaction testing of 205 various metal powder mixes has been carried out.•The validity of the compaction eq. P=P0.exp(K.pn) was tested.•P, P0 - porosities at pressure p and p=0; K, n are synergistically acting parameters.•The relationship between the parameters K and n, ln(K)=1.2952–7.3349.n, was found.•In terms of practical use the graphical relationship between P/P0, p and n was done.