Inspection device for manufacturing a part with addition of material

A manufacturing device for manufacturing a piece with addition of material, comprising energy supply means adapted to transform a quantity of material to be added to the piece being manufactured, within a transformation zone of the material which is effective at a time when said quantity of material is being fixed to the piece, the manufacturing device further comprising optical inspection means for providing at least one representation of the transformation zone in real time while the piece is being manufactured, said optical inspection means comprising:

• at least one inspection light source, adapted for producing an inspection light beam;
• an image sensor array;
• a beamsplitter, arranged to split the inspection light beam-into an illuminating beam and a reference beam;
• an illumination optical path, continually connecting the beamsplitter to the transformation zone while the piece is being manufactured, and intended for the illuminating beam;
• a reference optical path, continually connecting the beamsplitter to the image sensor array while the piece is being manufactured, and intended for the reference beam;
• and
• a transfer optical path, continually connecting the transformation zone to the image sensor array while the piece is being manufactured, and intended for the backscattered radiation that is produced by the illuminating beam when said illuminating beam is incident onto the transformation zone, said transfer optical path being adapted so that the backscattered radiation forms an image of the transformation zone on the image sensor array, the optical inspection means being arranged so that the image sensor array produces, for each readout sequence of said image sensor array, readout data which correspond to a superposition of the backscattered radiation transmitted by the transfer optical path with the reference beam transmitted by the reference optical path,
• each inspection light source being a laser source, and the readout data from the image sensor array, for each readout sequence of said image sensor array, forming a holographic image of the transformation zone which relates to a time when the piece is being manufactured, the optical inspection means further comprising at least one processor adapted for executing an algorithm for extracting a two-dimensional phase distribution from the holographic image, and converting the two-dimensional phase distribution into numerical values which characterize a topography of the transformation zone, so as to provide a three-dimensional representation of said transformation zone,
• the manufacturing device being of additive manufacturing type using selective melting produced by laser onto powder bed, wherein the energy supply means comprise a fusion laser and focusing optics adapted for focusing, on the transformation zone, a fusion laser beam produced by the fusion laser, so as to form selectively in said transformation zone, a melt pool from a powder of the material that is intended to form the piece, and
• wherein at least part of the focusing optics is arranged on a portion common to the illumination optical path and to the transfer optical path, so that the illuminating beam is incident onto the transformation zone after having passed through said part of the focusing optics, and the backscattered radiation passes through said part of the focusing optics in the direction of the image sensor array.