The present disclosure discloses methods and systems for removing dross from a liquid metal chamber, such as would be used in magnetohydrodynamic (MHD) or metal 3D printing. The method and systems comprise inserting a dross removal tool into a liquid metal chamber. A seal is compromised, fluidically connecting an evacuated volume and the liquid metal chamber. Pressure equalizes between the fluidically coupled volumes through an inflow of gas, liquid, and solid components from the liquid metal chamber into the dross removal tool. The dross removal tool is removed from the liquid metal chamber.

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.

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.

A three-dimensional (3D) metal object manufacturing apparatus is equipped with two solid metal moving mechanisms that are independently operated to move two different metals into the receptacle of a vessel in a melted metal drop ejecting apparatus. The ejector is operated to form object features with melted metal drops of one of the two different metals and to form support features with melted metal drops of the other of the two different metals. The thermal expansion coefficients of the two metals are sufficiently different that the support features easily separate from the object features after the object and support features cool.

A three-dimensional (3D) metal object manufacturing apparatus is equipped with two solid metal moving mechanisms that are independently operated to move two different metals into the receptacle of a vessel in a melted metal drop ejecting apparatus. The ejector is operated to form object features with melted metal drops of one of the two different metals and to form support features with melted metal drops of the other of the two different metals. The thermal expansion coefficients of the two metals are sufficiently different that the support features easily separate from the object features after the object and support features cool.

A method for producing a three-dimensional shaped article includes a first shaping step of shaping a first portion of the three-dimensional shaped article by ejecting a shaping material to a stage, and a second shaping step of shaping a second portion of the three-dimensional shaped article having an overlapping portion overlapping with the first portion, and a non-overlapping portion that does not overlap with the first portion, that forms a space between the same and the first portion, and that is in contact with the overlapping portion at one end. In the second shaping step, the overlapping portion is shaped by ejecting the shaping material onto the first portion, and thereafter, the non-overlapping portion is shaped by ejecting the shaping material so as to be in contact with the overlapping portion.

A three-dimensional printing system includes a print bed and a shelf insertion mechanism for inserting a shelf of one or a plurality of auxiliary shelves into a print volume between the print bed and a printer head. A printer assembly is configured to deposit layers of material within the print volume to form one or more objects on a support platform, the support platform including the print bed or an auxiliary shelf that is inserted into the print volume by the shelf insertion mechanism. A controller is configured to control the shelf insertion mechanism to insert an auxiliary shelf between the print bed and a printer head of the system after formation of the objects on that support platform by the printer assembly is complete.

A three-dimensional printing system includes a print bed and a shelf insertion mechanism for inserting a shelf of one or a plurality of auxiliary shelves into a print volume between the print bed and a printer head. A printer assembly is configured to deposit layers of material within the print volume to form one or more objects on a support platform, the support platform including the print bed or an auxiliary shelf that is inserted into the print volume by the shelf insertion mechanism. A controller is configured to control the shelf insertion mechanism to insert an auxiliary shelf between the print bed and a printer head of the system after formation of the objects on that support platform by the printer assembly is complete.

A method of controlling sensing level in a liquid ejector is disclosed. The method includes filling a reservoir in communication with a liquid ejector with a printing material to a first level set point, receiving a drop out signal from a laser-based level sensor that reads from a surface of a melt pool in the reservoir, pausing an operation of the liquid ejector, adjusting the printing material level set point to a second level set point of printing material in reservoir that is higher than the first level set point, increasing a quantity of printing material in the reservoir to fill the reservoir to the second level set point, and resuming the operation of the liquid ejector.

A method and apparatus for manufacturing an equiaxed crystal aluminum alloy cast ingot by using additive manufacturing and rapid solidification techniques are provided. The apparatus comprises: a metal heating mechanism and a negative pressure cooling mechanism. The metal heating mechanism is located above the negative pressure cooling mechanism and is connected thereto by a nozzle. The negative pressure cooling mechanism comprises a vacuum chamber having an air inlet hole and an air outlet hole, and a three-dimensional moving ingot mechanism disposed inside the vacuum chamber. The three-dimensional moving ingot mechanism comprises a moving ingot and a two-dimensional moving platform vertically connected to the moving ingot. A water cooling mechanism is disposed outside the moving ingot, and the moving ingot is driven by a precision motor to precisely move up and down.