Failure risk in powder-compacted parts

Abstract

Abstract

This article addresses the occurrence of crack-related failure within the powder compaction cycle. Both tensile and shear cracks are considered together with the challenges associated with their detection. Experimental data are presented from the compaction of multi-level parts pressed from DistaloyAE powder to green densities between 6 and 7 g/cm³. This is compared with process simulation results. Both point to compact fragility and that failure is reflected in a dilation mechanism. This is contrary to expectation where a shear-type failure was expected. Simulation of the compaction and ejection of a plain cylinder were also undertaken. This highlighted the impact of punch hold down and how it may be used to achieve part integrity through control of stress excursion within the compact. The final part of the article describes, for the first time, the integration of a failure risk model within compaction simulation. As a proof of concept, this was demonstrated to highlight high-risk areas for failure within the compaction cycle.