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 and an apparatus for collecting powder samples in real-time in powder bed fusion additive manufacturing may involves an ingester system for in-process collection and characterizations of powder samples. The collection may be performed periodically and uses the results of characterizations for adjustments in the powder bed fusion process. The ingester system of the present disclosure is capable of packaging powder samples collected in real-time into storage containers serving a multitude purposes of audit, process adjustments or actions.

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 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 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 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.

In an example implementation, a method of printing a multi-structured three-dimensional (3D) object includes forming a layer of sinterable material. The method includes processing a first portion of the sinterable material using first set of processing parameters and processing a second portion of the sinterable material using a second set of processing parameters. The processed first and second portions form, respectively, parts of a first and second structure of a multi-structured 3D object.

In one example, a print head drop detector (202) is described. The print head drop detector (202) comprises a sampling volume and a fan (208) to cause an airflow though the sampling volume (206). Detection apparatus to detect the presence of non-gaseous material within the sampling volume is also provided.

Adjustment of a halftoning threshold can, in an example implementation, include assigning a relative energy value, relative to a reference energy value, to a location of a build area and adjusting a halftoning threshold based on the relative energy value.