Investigating the effect of compaction parameters on the dimensional changes on sintering

Anisotropic dimensional change on sintering has been studied in depth in previous work, as affected by powder mix, geometry, sintering conditions etc. Previous results also revealed anisotropic dimensional changes in the compaction plane, to be necessarily considered when designing precise and accurate parts. Anisotropy in the compaction plane is expected to be markedly affected by inhomogeneities in green density distribution, in turn related to compaction strategy. Aiming at investigating in depth the influence of the compaction strategy, compaction speed, hold down force, and hold down time were selected as parameters. Full factorial testing was performed, three levels for each parameter, and three different materials were considered. Dimensional changes were measured, and the effect of the selected parameters was analyzed, also referring to the different sintering mechanisms occurring in the different materials. As a result, relationships describing the effect of the compaction parameters on the dimensional changes are proposed.