Method for producing a turbomachine part by means of a laser process

Abstract

The invention relates to a method for producing a part by means of a laser beam, with a nozzle ( 1 ) that sprays a metal powder towards a substrate ( 5 ). Initially, the trajectory of the nozzle is defined in a pre-determined manner, and then, during the production of the part ( 7 ): a theoretical reference distance D 0 that has been previously recorded and a real distance which is then measured are compared, and the trajectory of the nozzle is modified on the basis of a deviation threshold between said distances.

1 . A method for producing or repairing a turbomachine part by means of a laser beam, wherein a nozzle sprays a metal powder towards a substrate so as to produce the part by successive depositions of layers on top of each other, in one direction, therefore making the nozzle follow a trajectory, and wherein the trajectory of the nozzle is initially defined in a pre-determined manner, and then, during the production of the part:
 referring to an orientation parallel to the direction of deposition of the layers, a theoretical reference distance that has been previously recorded and a real distance which is then measured are compared; and   the trajectory of the nozzle is modified on the basis of a non null deviation threshold between the theoretical reference distance and the measured real distance.   
     
     
         2 . The method of  claim 1 , wherein:
 defining the predetermined trajectory of the nozzle initially includes a definition of said trajectory along a Z axis corresponding to said direction of deposition of the layers and a height of the part,   the real distance is measured along said Z axis,   and the trajectory of the nozzle is modified along said Z axis.   
     
     
         3 . The method of  claim 1 , wherein:
 the part is produced while stepwise moving the nozzle away from the substrate, in said direction of deposition of the layers,   the predetermined trajectory of the nozzle includes a predetermined number of such steps,   and the trajectory of the nozzle is modified by changing said predetermined number of steps.   
     
     
         4 . The method of  claim 1 , wherein:
 a predetermined number of said layers to be deposited corresponds to the predetermined trajectory of the nozzle,   a modified number of said layers still to be deposited corresponds to the modified trajectory of the nozzle,   and the trajectory of the nozzle is modified by substituting the modified number of layers still to be deposited with said predetermined number of layers to be deposited.   
     
     
         5 . The method of  claim 1 , wherein the part is produced by successive depositions on top of each other of layers having the same thickness, by moving the nozzle away from the substrate, for each layer, in said direction of deposition of the layers. 
     
     
         6 . The method of  claim 1 , wherein during the production of the part, said real distance is measured and/or the trajectory modified only after the deposition of several layers, if said deviation is reached. 
     
     
         7 . The method of  claim 1 , wherein said deviation threshold between the theoretical reference distance and the measured real distance is equal to the thickness of a layer. 
     
     
         8 . The method of  claim 1 , wherein a camera with an autofocus system is used to obtain the theoretical reference distance and the real distance. 
     
     
         9 . The method of  claim 2 , wherein:
 the laser beam is emitted along said Z axis,   and the theoretical reference and real distances are measured away from said Z axis, parallel to this axis or at an angle having a projection parallel to said Z axis.   
     
     
         10 . The method of  claim 1 , wherein a determined distance, between the substrate and one end of the nozzle facing said substrate corresponds to the theoretical reference distance, in said direction of deposition of the layers, and this determined distance is maintained during the production of the part, at the beginning or the end of the deposition of each layer.