Patent ID: 8968641
Filing Date: 2015-03-03
Classification: B22F

Abstract:
1. A process for producing porous metallic materials comprising the steps of: a. homogeneously mixing a composition consisting of metallic particles, a carbonate additive and a binder, wherein the metallic particles have a higher melting point than the melting or decomposition point of the carbonate additive and the quantity of carbonate additive in the mixture is in the range of 40 to 90 vol % and compressing the mixture in a mould beyond the yield strength of the metallic particles, so as to bring about a plastic strain of at least 0.0002 and plastic deformation of the metallic particles; b. heating the mixture to a first temperature sufficient to evaporate the binder; c. heating and maintaining the temperature of the mixture to a second temperature sufficient to sinter the metallic particles but insufficient to decompose or melt the carbonate additive, sintering thereby occurring before removal of the carbonate additive; d. allowing the material to cool and dissolving and removing the carbonate additive from the sintered porous metallic material prepared in step (c) in an aqueous solution in a manner that prevents the porous metallic material from collapsing after the carbonate additive is removed, so that the pores of said porous metallic material approximate the shape and size of the carbonate additive particles; and e. optionally heating and maintaining the temperature of the porous metallic material to a third temperature greater than the second temperature so as to enhance the sintering.