A fractographic and microstructural analysis of the neck regions of coarse copper particles consolidated by spark plasma sintering

The effect of the surface overheating occurring during spark plasma sintering was investigated by means of a fractographic and microstructural analysis of specimens produced with large copper particles. The overheated layer is quite thick and its microstructure is clearly different from that of the bulk of the particles, comprising coarse columnar grains oriented along the radial direction. Such a microstructure indicates that the temperature at the surface of the particles may effectively overcome the melting point of the material, leading to fast melting and re-solidification. © 2013 Elsevier B.V. All rights reserved.