Corrosion in 316L porous prostheses obtained by gelcasting

GREGORUTTI, RICARDO; ELSNER, CECILIA I.; L.B. GARRIDO; A. OZOLS

Procedia Materials Science

Elsevier

Año: 2015 vol. 9 p. 279 - 284

Gelcasting(GC) process, usually used for ceramic moulding, is adapted for producingspongy or porous metal osteosynthesis components destined to bone voidfilling.  The main objective of theinterconnected porosity is to improve the osteoconductive of metal matrix byingrowth of bone. Further, porosity reduces metal density and Young module,which causes bone resorption, leading to implant failure, phenomenon known asstress shielding. The employed GC is based on the formulation of AISI 316Lstainless steel powder suspension in an aqueous solution of organic polymers.This suspension is cast into porous ceramic shells, like those used in lost waxtechnique, wherein the polymer crosslinking is induced by heating. The shells,containing the resulting hydrogel?metal composite, are subjected to thermalcycle in order to dry, burn the organic phase, sinter the metal particles at 1200 °C, and cool down toroom temperature under dry hydrogen permanent flow. The susceptibility tocorrosion of 50-60 % porous pieces was analyzed. The results indicated that thelower relation between the open porosity and the total porosity, the lower thecorrosion rate.