Abstract: The invention relates to a method for the rapid manufacture of a three-dimensional workpiece from a molten material (1), in particular a molten metal, in which method the molten material (1) is supplied to a compression chamber (2) and delivered in drop form via an injector hole (4) by means of a pressure pulse which is generated with the aid of a reciprocating piston (3) that delimits the compression chamber (2). According to the invention, the compression chamber (2) is degassed before manufacturing begins and/or during a pause in the manufacturing. In a first step, ultrasonic waves are coupled into the molten material (1) in the compression chamber (2), which generate a force (FBjrk) that makes the gas in the molten material (1) sink, and in a second step, after the ultrasonic excitation has ended, the piston (3) is introduced deeper into the compression chamber (2) in order to remove the rising gas via a conduit (5) of the piston (3).

Abstract: The invention relates to an apparatus for the additive manufacture of a three-dimensional workpiece from a metal melt (1) containing aluminum, in particular an aluminum melt, comprising a compression chamber (2) which receives the metal melt (1) and is delimited by a piston (3) that is movable back and forth and by a nozzle body (4) having a nozzle bore (5) for discharging the metal melt (1) in drop form, wherein the nozzle body (4) has a metallophobic, in particular aluphobic structure (18), at least in the region (8) of a surface (7) adjoining the nozzle bore (5), which surface is arranged on the side facing away from the compression chamber (2),

Abstract: The invention relates to a method for the additive manufacturing of a three-dimensional workpiece from a liquid material (1), in which method the liquid material (1) is fed to a displacement chamber (2) and discharged in drop form via a jet hole (4) by means of a pressure pulse which is generated with the aid of a reciprocating piston (3) delimiting the displacement chamber (2). According to the invention, in order to optimise the wetting properties of at least one surface (5, 6) which delimits the displacement chamber (2) and/or the jet hole (4), sound waves are coupled into the liquid material (1) for a limited period of time with the aid of the piston (3) which is caused to vibrate for this purpose. The invention also relates to a device for carrying out the method according to the invention.