Hi,
As metal 3D printing is highly expensive, independent manufacturing capability of metal parts with complex internal geometry for individuals/small groups is largely inaccessible. The nearest alternative, sand casting is sometimes used for prototyping however it is still highly constrained in internal geometry, offers poor surface finish, is difficult to learn, has a seam, and it can be difficult to translate cad models into real world mold patterns. Thus enters lost foam casting (Lost-foam casting - Wikipedia) which is an alternative to investment casting (Investment casting - Wikipedia) that uses a polymer foam with a low boiling point to create an internal structure that then evaporates and is released when in contact with molten metal during the casting process. This eliminates the complex and failure prone dewaxing process from investment casting however there are currently no ways to additively manufacture these “foam” patterns. Additionally, low quality parts could potentially be made with these patterns by just burying one in casting sand and making a tube to the surface.
My question was whether there were any resins that exist or could be designed with a low enough boiling point to create these patterns while using the resolution of the resin printer to create an extremely low density structure like foam? (a potential benefit of 3D printed internal structures over foam is that they can be topologically optimized to have as minimal thickness/maximum surface area as possible to facilitate complete evaporation while also allowing metal to reach the outer parts of the mold quickly which mitigates issues even if the resin can’t be made to have quite as low of a boiling point as polystyrene foam)