Patent ID: 11890675
Assignee: FRAUNHOFER GESELLSCHAFT ZUR FÖRDERUNG DER ANGEWANDTEN FORSCHUNG E.V.
Field: Materials, metallurgy (Chemistry)
Classification: CPC B  Y | IPC B

Claim 0:
1. An apparatus for adjusting a powder flow in relation to the central longitudinal axis of an energy beam of a laser beam for a working head designed for powder deposition welding, wherein
the powder flow by means of a powder feed arranged on the side of the working head that faces a workpiece and is formed with an annular gap nozzle is embodied to be conical in the direction of the workpiece, with a plurality of annularly arranged nozzles or with at least two oppositely arranged nozzles inclined at an angle and the exit openings of which face one another, and designed such that particles of powdery material meet from several directions at an acute angle in a region which
is arranged above a surface on which the powdery material melted from the energy of the energy beam is to be deposited, and
the energy beam is aligned with respect to the plane on which molten powdery material is to be deposited, and
a device for two-dimensional or three-dimensional alignment of the powder feed in relation to the central longitudinal axis of the energy beam, specifically the optical axis of a laser beam, is provided at the working head in a plane oriented perpendicular to the central longitudinal axis of the energy beam,
from a radiation source, electromagnetic radiation is directed as a linear beam from a side into the region in which the particles of the powdery material meet, and
an optical two-dimensional detector array is arranged in a plane that is perpendicular to the linear beam,
the optical two dimensional detector arrayspatially captures intensities of the electromagnetic radiation and
is connected to a computer programmed to function as an electronic evaluation unit which
determines the shape, size and/or length of an irradiated region in which intensities that exceed a specifiable threshold value have been captured with the optical two-dimensional detector array in a spatially resolved manner and,
the irradiated region extends from surfaces of particles of the powdery material which the laser beam, which is operated with reduced power during the adjustment, strikes a partial region of the irradiated region that is in the direction of the particles of the powdery material accelerated towards a workpiece surface, in which the particles of the powdery material heated by the laser beam move divergently.