Medium-Frequency Electrical Resistance Sintering of Oxidized C.P. Iron Powder
Juan Manuel Montes,
Francisco Gómez Cuevas,
Fátima Ternero,
Raquel Astacio,
Eduardo Sánchez Caballero,
Jesús Cintas
Affiliations
Juan Manuel Montes
Metallurgy and Materials Engineering Group Escuela Técnica Superior de Ingeniería, Universidad de Sevilla Camino de los Descubrimientos s/n, 41092 Sevilla, Spain
Francisco Gómez Cuevas
Department of Chemical Engineering, Physical Chemistry and Materials Science Escuela Técnica Superior de Ingeniería, Universidad de Huelva Campus El Carmen, Avda. Tres de Marzo s/n, 21071 Huelva, Spain
Fátima Ternero
Metallurgy and Materials Engineering Group Escuela Técnica Superior de Ingeniería, Universidad de Sevilla Camino de los Descubrimientos s/n, 41092 Sevilla, Spain
Raquel Astacio
Metallurgy and Materials Engineering Group Escuela Técnica Superior de Ingeniería, Universidad de Sevilla Camino de los Descubrimientos s/n, 41092 Sevilla, Spain
Eduardo Sánchez Caballero
Metallurgy and Materials Engineering Group Escuela Técnica Superior de Ingeniería, Universidad de Sevilla Camino de los Descubrimientos s/n, 41092 Sevilla, Spain
Jesús Cintas
Metallurgy and Materials Engineering Group Escuela Técnica Superior de Ingeniería, Universidad de Sevilla Camino de los Descubrimientos s/n, 41092 Sevilla, Spain
Commercially pure (C.P.) iron powders with a deliberate high degree of oxidation were consolidated by medium-frequency electrical resistance sintering (MF-ERS). This is a consolidation technique where pressure, and heat coming from a low-voltage and high-intensity electrical current, are simultaneously applied to a powder mass. In this work, the achieved densification rate is interpreted according to a qualitative microscopic model, based on the compacts global porosity and electrical resistance evolution. The effect of current intensity and sintering time on compacts was studied on the basis of micrographs revealing the porosity distribution inside the sintered compact. The microstructural characteristics of compacts consolidated by the traditional cold-press and furnace-sinter powder metallurgy route are compared with results of MF-ERS consolidation. The goodness of MF-ERS versus the problems of conventional sintering when working with oxidized powders is analyzed. The electrical consolidation can obtain higher densifications than the traditional route under non-reducing atmospheres.
