Compaction density variation in powder metallurgy components

Abstract

The main objective of this research was to study the relationship between green density and compaction pressure in powdered metallurgy. Powder metallurgy has gained popularity and importance because of its near net shape, cost effectiveness and its ability to reduce the complexity of multileveled engineering components. However, powder metallurgy poses challenges that are yet to be fully understood. There are many works performed to address challenges such as the effect of friction, the tool kinematics, handling component prior to sintering and fracture under compaction. This work concentrates on the relationship between green density distribution and compaction pressure. In order to measure the relative density of compacted components, Electron Scanning Microscope was utilized. One can intuitively conceive that the relative density requires more than intuition. It was determined that highest relative density occurs at the center of the specimen and reduces toward the die-powder or punch-powder boundary. For completeness, the application of artificial neural network (ANN) and finite element (FE) model in estimation of green relative density was studied. The results of this research signify that ANN is an excellent technique to determine the relative density distribution of un-sintered compacted specimen. Moreover, finite element method can accurately estimate the average relative density of compacted specimen.