Methods for fabricating three-dimensional metallic objects via additive manufacturing using metal oxide pastes

A method of forming a three-dimensional metallic object, the method comprising:

• (a) extruding a metal oxide paste comprising metal oxide particles;
• a polymeric binder;
• and an organic solvent, through a tip to deposit sequential layers of the metal oxide paste on a substrate, whereby a three-dimensional metal oxide object is formed on the substrate, and
• (b) exposing the three-dimensional metal oxide object to a reducing gas at a temperature and for a period of time sufficient to reduce and to sinter the metal oxide particles, whereby the three-dimensional metallic object is formed,
• wherein the metal oxide paste comprises ceramic particles which are different from the metal oxide particles, and further wherein the ceramic particles are non-reducing ceramic particles.

A method of forming a three-dimensional metallic object, the method comprising:

• (a) extruding a metal oxide paste comprising metal oxide particles;
• a polymeric binder;
• and an organic solvent, through a tip to deposit sequential layers of the metal oxide paste on a substrate, whereby a three-dimensional metal oxide object is formed on the substrate, and
• (b) exposing the three-dimensional metal oxide object to a reducing gas at a temperature and for a period of time sufficient to reduce and to sinter the metal oxide particles, whereby the three-dimensional metallic object is formed,
• the method further comprising forming the metal oxide paste by forming a homogeneous suspension of the metal oxide particles coated by the polymeric binder in the organic solvent and thickening the homogeneous suspension by mixing the suspension at a temperature for a period of time sufficient to achieve a viscosity of about 25 Pa·s for the metal oxide paste.