Particle stereolithography
Systems, methods, components, and materials are disclosed for stereolithographic fabrication of three-dimensional, dense objects. A resin including at least one component of a binder system and dispersed particles can be exposed to an activation light source. The activation light source can cure the at least one component of the binder system to form a green object, which can include the at least one component of the binder system and the particles. A dense object can be formed from the green object by removing the at least one component of the binder system in an extraction process and thermally processing particles to coalesce into the dense object.
1. A method for the stereolithographic fabrication of a three-dimensional object as a plurality of successive layers, comprising the steps of:
providing a layer of resin, wherein the resin includes a first binder having a melt temperature, a second binder that is immiscible in the first binder and which crosslinks or polymerizes upon sufficient exposure to light of a predetermined wavelength, and at least one of ceramic particles and metal particles, wherein the resin has a temperature above the melt temperature of the first binder;
exposing a portion of the layer of resin to a pattern of light from a light source to cure the portion of the layer of resin into one of the plurality of the successive layers by curing the second binder without curing the first binder;
repeating the steps of providing a layer of resin and exposing a portion of the layer of resin to a pattern of light to form a green form of the three-dimensional;
conducting a first debinding process to debind the first binder, wherein during the first debinding process the first binder is at a temperature above the melt temperature;
conducting a second debinding process to debind the second binder; and
thermally processing the green form of the three-dimensional object until the at least one of ceramic particles and metal particles densify to a finished form of the three-dimensional object.
2. The method of claim 1 wherein the first debinding process includes debinding the first binder by exposing the green form of the three-dimensional object to water.
3. The method of claim 1 wherein the first debinding process includes thermally debinding the first binder.
4. The method of claim 3 wherein the second debinding process includes thermally debinding the second binder.
5. The method of claim 4 wherein the light source is a digital light processing (DLP) projector controllable to project an image on the resin.
6. The method of claim 5 wherein the step of thermally processing of the green form of the three-dimensional object includes sintering the at least one of ceramic particles and metal particles.
7. The method of claim 6 wherein the step of thermally processing the green form of the three-dimensional object includes infiltrating the green form of the three-dimensional object.
8. The method of claim 7 wherein during the step of providing a layer of resin a film is moved in an indexed fashion in a direction having a component parallel to the layer of resin.
9. The method of claim 1 , wherein the first binder is a wax.
10. The method of claim 1 , wherein the first binder is at least one selected from the group consisting of paraffin wax, carnauba wax, stearic acid, polyethylene glycol, polyoxymethylene, oleic acid, and dibutyl phthalate.
11. The method of claim 1 , wherein the second binder is at least one selected from the group consisting of poly(methyl methacrylate), polyethylene glycol diacrylate, urethane oligomers functionalized to acrylate groups, epoxy oligomers functionalized to acrylate groups, 1,6-Hexanediol acrylates, and styrene.