A method for large-scale, real-time simultaneous additive and subtractive manufacturing is described. The apparatus used in the method includes a build unit and a machining mechanism that are attached to a positioning mechanism, a rotating platform, and a rotary encoder attached to the rotating platform. The method involves rotating the build platform; determining the rotational speed; growing the object and the build wall through repetitive cycles of moving the build unit(s) over and substantially parallel to multiple build areas within the build platform to deposit a layer of powder at each build area, leveling the powder, and irradiating the powder to form a fused additive layer at each build area; machining the object being manufactured; and cutting and removing the build wall. The irradiation parameters are calibrated based on the determined rotational speed.

Before performing additive manufacturing of an article to be formed, a first scale plate is scanned in a first scanning speed so that a trace of the electron beam is depicted. An electric current value through a focusing coil with which the trace of the electron beam becomes narrowest is found and set as a melting electric current value. Then, a second scale plate is scanned similarly in the first scanning speed so that a trace of the electron beam is depicted. An electric current value through the focusing coil with which the trace of the electron beam cannot be seen is found and set as a preheating focusing electric current value. Dispersed metal powder is scanned with electron beam of the preheating electric current value as set before in a second scanning speed 20 to 30 times of the first scanning speed. Thereafter, the additive manufacturing is performed.

Excessive evaporation of powder is prevented. A three-dimensional shaping apparatus includes an electron gun that generates an electron beam, at least one deflector that deflects the electron beam one- or two-dimensionally, at least one lens that is provided between the electron gun and the deflector, and that focuses the electron beam, and a controller that controls the deflection direction and scanning speed of the deflector, the deflector scanning and irradiating the predetermined regions. The three-dimensional shaping apparatus further includes a controller that controls the cross-sectional diameter of the electron beam. The process step of melting the powder is divided into two process steps, namely the first melting step and the second melting step in the sequential order of the process steps. In the first melting step, the powder is given the amount of unit-area heat necessary to raise the temperature of the powder from its preheating temperature to its melting point. In the second melting step, the powder is given the amount of unit-area heat equal to or larger than the amount of unit-area heat necessary for the powder to melt by receiving its melting heat. In the second melting step, furthermore, the cross-sectional diameter of the beam is increased so that the powder is given a smaller amount of unit-area amount of unit-area power of the electron beam in the second melting step than in the first melting step.

A method of manufacturing a component using electron beam melting includes providing a powder layer; selectively melting at least a part of the powder layer so as to generate a solid layer of the component using a first electron beam; identifying any defects in the solid layer by scanning the solid layer using a second electron beam; and then repeating these steps at least once so as to build up a shape corresponding to the component. The second electron beam has a lower power than the first electron beam. The method may also include steps of removing any identified defects in the solid layer by using the first electron beam to re-melt at least a part of the solid layer, and adjusting one or more parameters of the selective melting step so as to avoid future recurring defects based on stored data relating to the scanned solid layer.

The present invention relates to an apparatus for forming a three-dimensional article through successively depositing individual layers of powder material that are fused together so as to form the article, the apparatus comprising an electron beam source emanating an electron beam for fusing the powder material in a build tank, a hollow construction having an upper opening and a lower opening, means for moving the hollow construction between a first position and a second position, a synchronising unit for synchronising the movement of a powder distributor for applying the individual layers of powder material on the work table with the movement of the hollow construction so that the hollow metal construction is at the first position when fusing and/or heating the powder layer and at the second position when the powder distributor is distributing the powder material for forming the individual powder layers.

In an additive manufacturing apparatus using electron beam melting for manufacturing three-dimensional structures by laminating layers in which metal powder is selectively molten-solidified with electron beam, defect in current apparatus is to be removed such that electrons accelerated with a constant accelerating voltage are irradiated irrespective of filling rate or density of metal powder to be used for additive manufacturing. Voltage of power supply applied between a grid and an anode provided in an electron gun for generating electron beam is varied corresponding to filling rate and/or density of metal powder. With this, velocity of electron such that a position where thermal energy becomes maximum is taken as most suitable can be obtained.

Various embodiments include approaches for controlling an additive manufacturing (AM) process. In some cases, an AM system includes: a process chamber for additively manufacturing a component, the process chamber at least partially housing a plurality of distinct melting beam scanners, each of the distinct melting beam scanners configured to emit a melting beam, wherein each of the distinct melting beam scanners is independently physically movable within a corresponding region of the process chamber; and a control system coupled with the plurality of distinct melting beam scanners, the control system configured to control movement of at least one of the plurality of distinct melting beam scanners within the corresponding region based upon a geometry of the component.

The present disclosure generally relates to additive manufacturing systems and methods on a large-scale format. One aspect involves a build unit that can be moved around in three dimensions by a positioning system, building separate portions of a large object. The build unit has an energy directing device that directs, e.g., laser or e-beam irradiation onto a powder layer. In the case of laser irradiation, the build volume may have a gasflow device that provides laminar gas flow to a laminar flow zone above the layer of powder. This allows for efficient removal of the smoke, condensates, and other impurities produced by irradiating the powder (the gas plume) without excessively disturbing the powder layer. The build unit may also have a recoater that allows it to selectively deposit particular quantities of powder in specific locations over a work surface to build large, high quality, high precision objects.

The present disclosure generally relates to additive manufacturing systems and methods on a large-scale format. One aspect involves a build unit that can be moved around in three dimensions by a positioning system, building separate portions of a large object. The build unit has an energy directing device that directs, e.g., laser or e-beam irradiation onto a powder layer. In the case of laser irradiation, the build volume may have a gasflow device that provides laminar gas flow to a laminar flow zone above the layer of powder. This allows for efficient removal of the smoke, condensates, and other impurities produced by irradiating the powder (the gas plume) without excessively disturbing the powder layer. The build unit may also have a recoater that allows it to selectively deposit particular quantities of powder in specific locations over a work surface to build large, high quality, high precision objects.

An additive manufacturing apparatus is provided and may include at least one build unit; a build platform; and at least one collector positioned on the apparatus such that the at least one collector contacts an outer surface of a build wall as the build wall is formed during a build. Methods are also provided for manufacturing at least one object.