In situ partially degradable separation interface for fabrication of complex near net shape objects by pressure assisted sintering

A method consisting of:

• 1) generating via 3D printing or other methods a polymer shell skeleton that can be decomposed into an immersed powder (or porous media) graphite shell skeleton inner interface;
• 2) surrounding of this rigid or semi-rigid polymer skeleton, wherein the skeleton can have a highly complex geometry, by the powder of the material(s) to be formed, wherein the powder of the sacrificial area can be different from the powder of the main part;
• 3) transforming this assembly of powder/polymer into a pure powders assembly by a heat treatment under vacuum or oxygen/hydrogen free atmosphere enabling the controlled degradation of the polymer interface into a graphite (or other thermally stable products of the polymer partial degradation) powder interface that does not join the adjacent parts during the sintering allowing the post sintering releasing of the internal complex parts;
• and
• 4) after sintering, releasing the internal complex parts,
• wherein the polymer shell model or polymer skeleton can be coated by an inner ceramic powder to prevent eventual undesired carbonization reaction between the graphite powder and the main part powders.