Automated de-powdering via liquid immersion
According to some aspects, a de-powdering subsystem for an additive fabrication system is described. The de-powdering subsystem may comprise a bath subsystem. The bath subsystem may comprise a reservoir configured to contain a liquid and to accept objects to be de-powdered into the liquid, and an agitation facility configured to cause currents within the liquid. The agitator facility may be at least one of (i) a pump configured to circulate the liquid within the reservoir, (ii) a heating element configured to generate convection currents in the liquid, and (iii) a stirrer driven through a linkage to a motor. The bath subsystem may comprise at least one ultrasonic transducer configured to apply ultrasonic vibrations to the liquid within the reservoir.
1. A method for separating one or more additively fabricated parts from a powder, the method comprising:
transferring a mixture of one or more additively fabricated parts and a powder into a container having a plurality of perforations therein, wherein the powder is a metal powder and wherein the additively fabricated parts comprise particles of the metal powder and at least one binding agent;
immersing at least part of the perforated container within a bath of a liquid, thereby immersing at least part of the mixture of the one or more additively fabricated parts and the powder in the liquid; and
generating fluid currents within the liquid which pass through perforations of the container and thereby convey at least some of the powder from the mixture of the one or more additively fabricated parts and the powder to outside of the container.
2. The method of claim 1 , wherein the fluid currents are generated, at least in part, by circulating the liquid through the bath with one or more pumps.
3. The method of claim 1 , wherein the fluid currents are generated, at least in part, by heating the bath of the liquid to produce convection currents.
4. The method of claim 1 , wherein the fluid currents are generated, at least in part, by a motorized stirrer arranged within the bath.
5. The method of claim 1 , wherein the fluid currents are generated, at least in part, by an ultrasonic transducer.
6. The method of claim 1 , wherein the liquid comprises water.
7. The method of claim 1 , wherein the liquid comprises a solvent.
8. The method of claim 1 , wherein the at least one binding agent is not soluble by the liquid.
9. The method of claim 1 , wherein the container is a basket.