Self-consolidation mechanism of porous-surfaced Ti implant compacts induced by electro-discharge-sintering of spherical Ti powders

Porous-surfaced Ti implant compacts, with a solid core surrounded by a porous layer, were self-assembled by electro-discharge-sintering directly from spherical Ti powders. During an electro-discharge, instant high temperatures through the Ti powder column ranged from 1093 to 4925 °C were generated in times as short as 86–153 µsec. At the same time, pinch pressures ranging from 11 to 38 MPa were applied, especially to the middle of the Ti powder column. The solid core size depended on both the pinch pressure magnitude and the heat generated during a discharge. Both the pinch pressure (to squeeze and deform Ti powder particles), and the heat (to weld them together), were key factors in the production of porous-surfaced Ti implant compacts. It is thus suggested that the input energy at constant capacitance is a controllable electro-discharge parameter affecting the porosity and strength of the porous-surfaced Ti implant compacts.