The role of diffusion versus plastic flow in the sintering of model compacts

Abstract

To establish whether mass transport during sintering occurs via a plastic flow or diffusional mechanism, a marker movement experiment was conducted using three-wire model compacts of cellulose acetate, potash borosilicate glass, nickel, and copper. During sintering, markers originally in the cellulose acetate and glass fibers moved with the material into the central void, indicating the predominance of a plastic (viscous) flow mechanism. Markers originally within the nickel and copper wires, however, within the resolution of the experiment, did not move with the flux of material to the central void, indicating that mass transport was by a diffusional rather than plastic flow mechanism. The aluminum and zirconium oxide particles used as markers in the copper wires brought about a pronounced inhibition of sintering whose cause is not yet understood.