Patent ID: 7481968

Claim:
A method for the preparation of a sintered porous body of particles of a metallic or ceramic powder which comprises the successive steps of: (a) blending a powder of a metallic or ceramic material with water, polyvinyl alcohol as a binder resin and a blowing agent to give an aqueous foamable composition; (b) subjecting the aqueous foamable composition to a freezing for effecting gelation of the polyvinyl alcohol to give a gelled mass of the composition; (c) subjecting the gelled mass of the composition to a heating treatment in a range from 40-90° C., under conditions that keep the PVA resin in a gelled state, for effecting foaming of the gelled polyvinyl alcohol resin to give a foamed body of the composition; and (d) subjecting the foamed body of the composition to a heat treatment so as to effect drying thereof and sintering of the particles of the metallic or ceramic powder.