Spark Plasma Sintering of Biomedical Alloys for Prosthesis Application

Spark Plasma Sintering (SPS) is an emerging powder metallurgy (PM) technology, which makes use of a pulsed electric current and compaction pressure for densification and sintering of powders. It is particularly suitable to process hard-to-sinter powders to the full density with a strict controlling of the microstructure due to the relatively low heat input. The work reported here was carried out during the doctoral school in the frame of an industrial research project in cooperation with K4Sint Srl (Trento, Italy), and Eurocoating SpA (Trento, Italy). The objective was the development of materials that match the international biomedical standards. It was attempted to establish the process parameters for the production of a highly porous (cp-Ti), full density materials (Ti-6Al-4V and Co-28Cr-6Mo), and their combination in a surface functionalized full density substrate. Co-sintering and sinter-bonding were the processing approaches used to join the scaffold and the full density substrate. The scaffold consisted in a sort of blend during sintering with subsequent space holder extraction; this ensured a careful controlling of the final porosity volume fraction, shape and size.