Rapid processing & characterization of micro-scale functionally graded porous materials

Spark plasma sintering (SPS) is a process that has stimulated worldwide interest for the rapid consolidation of powder-based materials through the combined effects of electric current and pressure. Recently the localization of SPS has been realized through current activated tip-based sintering (CATS) where electric current is selectively applied to small targeted regions of a green compact/powder bed via a precision controlled electrically conductive small tip. The unique tip-specimen geometry allows for locally controlled temperature and current distributions that can result in microstructural modifications on the micro-scale. The present paper presents for the first time the rapid processing and characterization of micro-scale functionally graded materials in relation to porosity content and size. The effects of initial green density and particle size on the developed micro-scale functionally graded material are discussed.