Provided are a jet device and systems and methods using the jet device for manufacturing objects by additive manufacturing, especially titanium and titanium alloy objects, wherein the jet device directs a cooling gas across a liquid molten pool, or to impinge on the liquid molten pool, or to impinge upon a solidified material adjacent to a liquid-solid boundary of the liquid molten pool, or to impinge on an as-solidified material, or any combination thereof, during the additive manufacturing process. The application of the cooling gas can result in an additively manufactured metal product having refined grain structure with a high proportion of the grains being approximately equiaxed, and can yield an additively manufactured product exhibiting improvements in strength, fatigue resistance, and durability.

A printer having a pump which includes an inner cavity which retains a liquid metal printing material, and a nozzle, where the nozzle is configured to eject a plurality of liquid metal drops, an actuation coil configured to supply a pulse to the liquid metal to generate an electromagnetic force upon the liquid metal, where the actuation coil supplies a pulse at a first time varying current pulse, where the electromagnetic force causes the nozzle to eject a drop of liquid metal. The actuation coil also supplies a pulse at a second time varying current pulse, where the electromagnetic force is not sufficient to eject a drop of liquid. A method for metal jetting in a printer is also disclosed where differences between the temperature in an upper portion of the pump and the temperature in a lower portion of the pump are minimized.

A three-dimensional (3D) metal object manufacturing apparatus is equipped with a liquid silicate application system to apply liquid silicate to a surface of a build platform prior to manufacture of a metal object. The liquid silicate layer is permitted to air dry and then the platform is heated to its operational temperature range for formation of a metal object with melted metal drops ejected by the apparatus. The liquid silicate layer forms a glassy, brittle layer on which the metal object is formed. This brittle layer is removed relatively easily with the object after the object is manufactured and the build platform is permitted to cool. The silicate layer improves the wetting of the surfaces of build platforms made with non-wetting materials, such as oxidized steel, while also preventing metal-to-metal welds with wetting materials, such as tungsten or nickel.

A metal object manufacturing apparatus is configured to eject melted metal drops to form a continuous metal line over a line of spatially separated pillars in a single pass. The ejection frequency for forming the continuous metal line is different than the frequency used to form the pillars. In one embodiment, the ejection frequency for forming the pillars is about 100 Hz and the frequency used to form the continuous metal line over the line of spatially separated pillars is about 300 Hz with a drop spacing of about 0.2 mm. Continuous metal lines are formed to extend the continuous metal lines over the pillars laterally to fill the gaps between the continuous metal lines over the pillars. These continuous metal lines that fill the gaps are formed while operating the ejection head at the 300 Hz frequency with a drop spacing of 0.28 mm.

An implementation of the present teachings includes inner shell for a printer, such as a liquid metal printer, that mitigates problems associated with the formation of dross. The inner shell can be installed in a reservoir of the printer during a printing process where, during the printing process, a dross can form on an interior sidewall of the inner shell. Subsequently, the inner shell can be removed and either cleaned or replaced. During printing, the inner shell can be raised and/or lowered, or otherwise repositioned, so that the dross forms over a larger surface area of the inner shell, and at a decreased thickness, compared to an inner shell that is not repositioned.

A composite equal additive manufacturing method: S1, obtaining molten metal by using a metal smelting device; S2, first, storing inflow molten metal in an intermediate container, and then transferring the molten metal into a crystallizer; S3, cooling the molten metal to a solid-liquid mixed state by using the crystallizer, and enabling a high-temperature blank body with a required section to flow out from an outlet of the crystallizer; S4, arranging plastic forming tools at a bottom of the outlet of the crystallizer, and performing plastic forming on the outflow high-temperature blank body; S5, fixing a lower end of a part after the plastic forming and slowly descending the part by a chuck; S6, machining the part by using point forming machines, and synchronously controlling the machining temperature of the part; and S7, descending the chuck to an appropriate position, and taking the formed part out from the machine frame.

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 three-dimensional (3D) metal object manufacturing apparatus has a plurality of thermally insulative members that float in a volume of heat transfer lubricating fluid in which a X-Y translation mechanism moves to position a platform opposite an ejector. The apparatus also includes a housing having an internal volume in which the platform and X-Y translation mechanism are located. The heat transfer lubricating fluid can be a molten salt, such as a molten fluoride, chloride, or nitrate molten salt. The thermally insulative members can be spheres made of zirconium oxide or zirconium dioxide. The thermally insulative layer formed by the members floating in the fluid protects the X-Y mechanism while the housing helps keep the surface temperature of the object being formed on the platform in an optimal range for bonding of melted metal drops ejected from the ejector to a surface of a metal object being formed on the platform.

A method of printing a three-dimensional object. The method comprises: supplying a print material that is electrically conductive to a plurality of ejector conduits arranged in an array, the ejector conduits comprising first ends configured to accept the print material and second ends comprising an ejector nozzle; advancing the print material in one or more of the ejector conduits of the array until the print material is disposed within the ejector nozzle of the one or more ejector conduits; providing a flux region in the print material disposed within the ejector nozzle; flowing electrical current through the print material in the flux region to thereby generate a Lorentz force on the print material and eject at least a portion of the print material from the ejector nozzle onto a print substrate; and repeating both the advancing of the print material and the flowing electrical current through the flux region to form a three-dimensional object on the print substrate.

A three-dimensional (3D) metal object manufacturing apparatus is equipped with a removable vessel to reduce the time required for start-up procedures after the printer is serviced. The removable vessel is filled with solid metal that is heated to its melting temperature before the bulk wire is inserted into the vessel to commence printing operations. The melting of the solid metal in the removable vessel requires less time that the melting of an length of bulk wire adequate to produce a volume of melted metal suitable for printer operation. The solid metal in the removable vessel can be metal pellets, metal powder, or a solid metal insert.