Study on fabrication and mechanism in of porous metals by spark plasma sintering

Porous stainless steel with regular spherical particles were fabricated by spark plasma sintering (SPS) and compared with those obtained by conventional hot pressing (HP). The effects of the parameters during sintering processes on properties, such as porosity and compressive strength, were investigated. Microstructure studies showed that the regular spherical stainless steel particle could form porous ingots with regular pores in the way of close sphere package. Results indicated that the compressive properties of the SPS samples were superior to those of the HP samples. The study on relative diffusion coefficient in SPS and HP specimens indicated that SPS enhanced neck growth and accelerated the atom diffusion. Porous metals could be superfastly prepared by SPS under the conditions of higher heating rate, shorter holding time and lower sintering temperature.