A method includes ejecting a plurality of drops of a build material from a nozzle of a 3D printer. The build material cools and solidifies after being ejected to form a 3D object. The method also includes controlling an oxidation of the drops, the 3D object or both to create different oxidation levels in first and second portions of the 3D object.

A microdroplet-based three-dimensional (3D) laser printing system, which includes a laser beam subsystem, a transparent donor substrate, voxel arrays, and the receiver substrate. By irradiating the voxel array with a pulsed laser beam deriving from the laser beam subsystem through the transparent donor substrate, the voxel array is melted and driven away from the transparent donor substrate to generate the ejecting microdroplet array and then deposited onto the receiver substrate. The 3D microstructure is printed in parallel by sequentially irradiating the voxel array and controlling the depositing locations of microdroplet arrays onto the receiver substrate. The system can avoid the satellite microdroplets generating, improve the printing efficiency and resolution, and obtain a wide process window.

A method includes moving a first part along a movement path. The method also includes introducing drops of a liquid metal onto the first part using a three-dimensional (3D) printer. The drops of the liquid metal solidify to form a second part that is joined to the first part. The method also includes mechanically joining the second part to a third part.

A metal fused, deposition printer, that uses the thixotropic (or other) properties of a metal (or alloy) to control the viscosity of the material being deposited. In the invention presented in this patent, the viscosity of the metal is controlled by shearing it before, during, or after the deposition process. Since thixotropic (or other) properties allow for the control of the viscosity separately from the temperature, the taught invention allows for precise control of the temperature differential between the layer being deposited, and the substrate layer.

A three-dimensional (3D) metal object manufacturing apparatus is equipped with a magnetic field generator to form a magnetic field selectively about a nozzle from which melted metal drops are ejected. The drops ejected in the presence of the magnetic field have their velocities reduced from the initial velocity at which they are ejected. The reduced velocity increases the time in flight of the drops before they impact their landing areas. The increased travel time enables the melted metal drops to oxidize sufficiently that they bond less tightly than the drops ejected without passing through the magnetic field. Thus, the apparatus can form metal support structures that adhere less tightly to the part portions of the object so they can be more easily removed after printing of the object.

The present invention relates to a method of printing a composite material (1), for example polymeric, carbonaceous, siliconic or metallic comprising steps of: i) providing a plurality of bundles (2) of reinforcement fibres (4), wherein the reinforcement fibres (4) have a length in the range 3-50 mm and are in the number of about 1,000-100,000 in each bundle (2); ii) aligning the bundles (2) along a predetermined path (X, X′); iii) incorporating at least part of the bundles (2) into a matrix (6, 8), for example polymeric, carbonaceous, siliconic or metallic, preserving the alignment along said path (X, X′); iv) laying and solidifying at least one layer (8) of the matrix (6, 8) of step iii) to make the composite material (1).

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 three-dimensional (3D) printer includes an ejector having a nozzle. The 3D printer also includes a heating element configured to heat a solid metal in the ejector, thereby causing the solid metal to change to a liquid metal within the ejector. The 3D printer also includes a coil wrapped at least partially around the ejector. The 3D printer also includes a power source configured to supply one or more pulses of power to the coil, which cause one or more drops of the liquid metal to be jetted out of the nozzle. The 3D printer also includes a substrate configured to support the one or more drops as the one or more drops solidify to form a 3D object. The 3D printer also includes a gas source configured to cause an oxygen concentration to be less than about 5% proximate to the one or more drops, the 3D object, or both.

A three-dimensional printing system includes a build platform comprising a build surface. The printing system also includes an enclosure system having a side portion extending entirely around the build surface, a top plate portion that abuts the side portion, and a bottom portion. The side portion, the top plate portion and the bottom portion form an enclosed space surrounding the build surface. The top plate portion is moveable so as to adjust a volume of the enclosed space. A 3D printer printhead is disposed adjacent to the enclosure system for depositing a print material onto the build surface. The printing system also includes a heating system for heating the enclosed space.

An apparatus for countergravity casting a metallic material, comprises: a crucible for holding melted metallic material; a casting chamber for containing a mold; a fill tube capable of extending into the crucible to communicate melted metallic material to the casting chamber; a gas source coupled a headspace of the melting vessel to allow the gas source to pressurize said headspace to establish a pressure differential to force the melted metallic material upwardly through said fill tube into said mold; and means for gettering sulfur.