Abstract

The invention relates to a source of electron beams which is suitable for selective additive manufacturing, comprising a cathode, the cathode comprising an emission region suitable for emitting electrons, a main Wehnelt electrode, an anode and a set of power supply units suitable for applying an electric voltage to these three parts, the main Wehnelt electrode being positioned between the cathode and the anode, said source comprising an additional Wehnelt electrode and a power supply unit suitable for applying an electric voltage to said additional Wehnelt electrode, said additional Wehnelt electrode being disposed upstream of the main Wehnelt electrode in the direction of propagation of the electron beam in such a way that a first control surface of the additional Wehnelt electrode surrounds an upstream portion of the emission region in the direction of propagation of the electron beam, and a second control surface of the main Wehnelt electrode surrounds a downstream portion of the emission region in the direction of propagation of the electron beam.

IPC Classes  ?

• H01J 37/305 - Electron-beam or ion-beam tubes for localised treatment of objects for casting, melting, evaporating, or etching
• B33Y 30/00 - Apparatus for additive manufacturingDetails thereof or accessories therefor
• B33Y 10/00 - Processes of additive manufacturing
• H01J 37/063 - Geometrical arrangement of electrodes for beam-forming
• H01J 37/075 - Electron guns using thermionic emission from cathodes heated by particle bombardment or by irradiation, e.g. by laser
• H01J 37/06 - Electron sourcesElectron guns

Abstract

The invention relates to an apparatus for manufacturing a three-dimensional object by selective additive manufacturing, comprising, in a chamber, a support for depositing successive layers of additive manufacturing powder, a distribution arrangement suitable for applying a layer of powder on the support or on a previously consolidated layer, at least one electron beam source suitable for selectively consolidating a powder layer applied by the distribution arrangement and electronics for controlling and feeding the source, characterised in that the source is an indirectly heated cathode electron beam source, the source comprising a heating filament (22) located behind the cathode (21) of the source with respect to the direction in which the electrons are ejected and accelerated by the cathode (21).

IPC Classes  ?

• B22F 3/105 - Sintering only by using electric current, laser radiation or plasma
• B23K 15/00 - Electron-beam welding or cutting
• H01J 37/317 - Electron-beam or ion-beam tubes for localised treatment of objects for changing properties of the objects or for applying thin layers thereon, e.g. ion implantation
• B28B 1/00 - Producing shaped articles from the material
• H01J 1/14 - Solid thermionic cathodes characterised by the material
• H01J 1/22 - Heaters
• H01J 19/06 - Thermionic cathodes characterised by the material
• H01J 19/16 - Heaters