Systems and methods for direct deposition of thixotropic alloys
A method may comprise: placing a probe in a molten metal melt comprising a thixotropic metal alloy; injecting a gas into the molten metal melt to form a saturated slurry, the saturated slurry being at a temperature above a liquidus temperature of the thixotropic metal alloy after injecting the gas; removing the probe from the molten metal melt; and depositing the molten metal melt through an extruder of an additive manufacturing system.
1 . An additive manufacturing system, comprising:
an extruder including a shot sleeve defining a cavity, an inlet duct in fluid communication with the cavity, a screw feeder disposed at least partially within the shot sleeve, and a nozzle, the screw feeder configured to rotate causing a molten metal melt to translate towards and out the nozzle;
a crucible configured to receive the molten metal melt, the crucible configured to be in fluid communication with the inlet duct during deposition;
a cooling gas; and
a probe configured to actuate into and out of the crucible, wherein the probe comprises a fluid port disposed therethrough and wherein the probe is configured to inject the cooling gas into the molten metal melt in the crucible, responsive to being actuated into the crucible, to remove a controlled amount of heat from the molten metal melt.
2 . The additive manufacturing system of claim 1 , wherein the nozzle is a heated nozzle.
3 . The additive manufacturing system of claim 1 , wherein the shot sleeve is a heated shot sleeve.
4 . The additive manufacturing system of claim 1 , further comprising a spool fiber feeder coupled to the extruder, the spool fiber feeder configured to feed a fiber into a deposited layer from the nozzle during deposition.
5 . The additive manufacturing system of claim 1 , further comprising a mechanical arm coupled to the extruder.
6 . The additive manufacturing system of claim 5 , further comprising:
at least one of a hot plate or an induction coil embedded within or coupled to the crucible; and
a controller in operable communication with the mechanical arm, the extruder, the crucible, and the probe, wherein the controller is configured to command the at least one of the hot plate or the induction coil to heat the crucible to a temperature above a liquidus temperature of the molten metal melt prior to deposition.