US 12,280,540 B2
In situ partially degradable separation interface for fabrication of complex near net shape objects by pressure assisted sintering
Charles Maniere, Toulouse (FR); and Eugene Olevsky, San Diego, CA (US)
Assigned to San Diego State University Research Foundation, San Diego, CA (US)
Filed by San Diego State University, San Diego, CA (US)
Filed on Mar. 12, 2024, as Appl. No. 18/602,537.
Application 18/602,537 is a continuation of application No. 17/042,176, filed on Sep. 27, 2020, granted, now 11,926,091, issued on Mar. 12, 2024.
Prior Publication US 2025/0042083 A1, Feb. 6, 2025
This patent is subject to a terminal disclaimer.
Int. Cl. B29C 64/153 (2017.01); B22F 10/00 (2021.01)
CPC B29C 64/153 (2017.08) [B22F 10/00 (2021.01)] 9 Claims
OG exemplary drawing
 
1. 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.