Method for treating raw-material powder, apparatus for treating raw-material powder, and method for producing object

Abstract

A method for treating a raw-material powder includes forming a layer of the raw-material powder and removing oxide film formed on a surface of the raw-material powder from which the layer has been formed.

What is claimed is: 
     
         1 . An apparatus for treating a raw-material powder in an object production system that uses powder bed fusion, the apparatus comprising:
 an evacuable enclosure;   atmosphere generator configured to generate, in the enclosure, an atmosphere containing hydrogen and/or an inert element;   a powder container located in the enclosure and electrically insulated from the enclosure;   a forming unit configured to form a layer of the raw-material powder in the powder container; and   an energizing unit configured to generate plasma in said atmosphere by applying an AC voltage to the layer formed by the forming unit, wherein the energizing unit has an electrode arranged to come into contact with the layer and apply the AC voltage to the layer in the powder container.   
     
     
         2 . The apparatus according to  claim 1  for treating a raw-material powder, wherein a surface of the powder container that comes into contact with the layer is insulating. 
     
     
         3 . The apparatus according to  claim 1  for treating a raw-material powder, wherein the energizing unit capable of superposing the AC voltage with a negative DC voltage. 
     
     
         4 . The apparatus according to  claim 1  for treating a raw-material powder, wherein the apparatus further comprising a heater, as a component of the powder container, arranged to heat the layer. 
     
     
         5 . An object production system that uses powder bed fusion, the object production system comprising:
 an apparatus for treating a raw-material powder;   wherein the apparatus includes:
 an evacuable enclosure; 
 atmosphere generator configured to generate, in the enclosure, an atmosphere containing hydrogen and/or an inert element; 
 a powder container located in the enclosure and electrically insulated from the enclosure; 
 a forming unit configured to form a layer of the raw-material powder in the powder container; and 
 an energizing unit configured to generate plasma in said atmosphere by applying an AC voltage to the layer formed by the forming unit, wherein the energizing unit has an electrode arranged to come into contact with the layer and apply the AC voltage to the layer in the powder container, and 
   a beam emitter configured to irradiate, with an energy beam, the layer that has been treated by the apparatus.   
     
     
         6 . An object constructed by powder bed fusion according to  claim 5 , comprising a crystal structure in which a crystal has grown in a stacking direction of layers, with an infill as measured by an Archimedes method being 99.9% or more. 
     
     
         7 . The system according to  claim 5  for producing an object, wherein the electrode arranged to come into contact with the layer is configured to not interfere with the irradiation of the layer by the beam emitter.