Method of manufacturing a component

An additive layer manufacture machine for manufacturing a component comprising:

• a powder delivery device configured to deliver successive layers of powder to a melt region;
• an energy source configured to selectively melt at least a part of each powder layer so as to produce a solid layer of the component;
• an electron beam source configured to generate a scanning electron beam to scan each melt region, including the solid layer;
• a backscatter detector configured to receive backscattered electrons resulting from the interaction between the electron beam and the melt region so as to be able to determine the geometry of the solid layer;
• and
• a control unit comprising a processor and memory, the control unit configured to:
• store data relating to the determined geometry of the solid layer;
• use the stored data to determine whether the determined geometry has errors that are outside an allowable tolerance of a desired geometry at the same position in two or more different solid layers, such geometry being said to have recurring errors;
• and
• if any such recurring errors are identified, adjust one or more parameters of the steps of providing a powder layer and/or selectively melting the powder layer so as to avoid future recurring errors at that position.

A method of manufacturing a component comprising:

• providing a powder layer to a melt region;
• selectively melting the powder layer using an energy source, the melted powder subsequently solidifying to form a solid layer;
• scanning the melt region, including the solid layer, using a scanning electron beam;
• detecting backscattered electrons resulting from the interaction of the scanning electron beam with the melt region;
• determining the geometry of the solid layer from the detected backscattered electrons;
• storing data relating to the determined geometry of the solid layer;
• repeating the steps of providing a powder layer, selectively melting the powder layer, scanning the melt region, detecting backscattered electrons, and storing data relating to the determined geometry for multiple powder layers;
• generating a virtual 3-D model of the manufactured component using the stored data relating to the determined geometry of the solid layers;
• and
• comparing the virtual 3-D model with desired geometry of the component, and if the virtual 3-D model is determined to be outside an allowable tolerance the desired geometry, deciding whether to scrap the component or correct the component.