Patent ID: 11878348
Assignee: JEOL LTD.
Field: Materials, metallurgy (Chemistry)
Classification: CPC B  Y | IPC B

Claim 8:
9. A three-dimensional powder bed fusion additive manufacturing method using a three-dimensional powder bed fusion additive manufacturing apparatus, comprising:
a build plate;
a plate moving device that moves the build plate in an up-down direction;
a powder application device that applies a powder material onto the build plate to form a powder layer, the powder application device comprising a squeegee that moves on the build plate to spread the powder material;
a beam irradiation device that irradiates the build plate or the powder layer with a beam;
a control unit configured or programmed to: control the plate moving device, the powder application device, and the beam irradiation device to form a manufactured object for one layer through a powder application step, a powder heating step, a sintering step, and an after-heating step, and to form a three-dimensional manufactured object by laminating the manufactured object for one layer;
a camera that photographs a manufactured surface of the powder layer; and
a determination unit configured or programmed to determine whether powder application failure of the powder material has occurred,
the method comprising:
the powder application step of applying a powder material onto the build plate by moving the squeegee in a horizontal direction on the build plate to form the powder layer;
the powder heating step of preheating the powder layer on the build plate after the powder application step;
the sintering step of sintering the powder material forming the powder layer after the powder heating step; and
the after-heating step of heating the powder layer on the build plate after the sintering step,
wherein, in the powder application step, it is determined whether powder application failure of the powder material has occurred using images of the manufactured surface photographed by the camera while and immediately after the squeegee passes through the manufactured surface of the powder layer,
wherein the determining whether powder application failure of the powder material has occurred uses an image photographed by the camera while the squeegee is passing through the manufactured surface to obtain a difference between a predicted feature value immediately after the squeegee passes and a feature value of an image immediately after the squeegee passes, the predicted feature value being predicted from a temporal change in a feature value of an image before the squeegee passes, and determines whether powder application failure of the powder material has occurred based on the obtained difference, and
wherein the feature value of the image is at least one of intensity and saturation of the image.