EP-4741084-A1 - INFORMATION PROCESSING APPARATUS, DEFECT DETECTION METHOD, AND THREE-DIMENSIONAL POWDER BED FUSION ADDITIVE MANUFACTURING APPARATUS

EP4741084A1EP 4741084 A1EP4741084 A1EP 4741084A1EP-4741084-A1

Abstract

An information processing apparatus (54) includes: a defect candidate specifying unit (72) that specifies a plurality of defect candidates that are located at substantially same positions in a plurality of layers that are adjacent in a stacking direction; a defect detection unit (73) that detects defects remaining in shaped objects on the basis of sizes of the plurality of defect candidates, which are located at substantially the same positions and are specified in the plurality of layers, in the stacking direction and sizes inside the layers; and a shaping control unit (71) that performs control to stop at least PBF-AM of shaped objects, from which the defects have been detected, or output a warning in a case where the sizes of the defects exceed a preset threshold value in the middle of the PBF-AM.

Inventors

TSUTAGAWA, NARI
KANEKO, YUHEI
ASANUMA, YUJI
TSUDA, TAKASHI
Suwa, Kento
Ohara, Shuma
SHIBATA, KOHEI

Assignees

Jeol Ltd.

Dates

Publication Date: 20260513
Application Date: 20251112

Claims (13)

An information processing apparatus comprising: a defect candidate specifying unit (72) that detects failure locations having occurred in layers, by which PBF-AM of shaped objects is performed, as defect candidates for each of the layers and specifies the plurality of defect candidates located at substantially same positions in the plurality of layers that are adjacent in a stacking direction on the basis of layer data obtained for each of the layers; a defect detection unit (73) that detects defects remaining in the shaped objects on the basis of sizes of the plurality of defect candidates, which are located at substantially the same positions and are specified in the plurality of layers, in the stacking direction and the sizes thereof inside the layers; and a shaping control unit (71) that performs control to stop at least the PBF-AM of shaped objects from which the defects have been detected or to output a warning in a case where the sizes of the defects exceed a preset threshold value in a middle of the PBF-AM.
The information processing apparatus according to claim 1, wherein the shaping control unit (71) performs first control of stopping the PBF-AM of all the shaped objects.
The information processing apparatus according to claim 1, wherein the shaping control unit (71) performs second control of stopping the PBF-AM of the shaped objects from which the defects have been detected and continuing the PBF-AM of remaining shaped objects.
The information processing apparatus according to claim 1, wherein the shaping control unit (71) performs third control of outputting a warning indicating that the defects have been detected.
The information processing apparatus according to claim 1, comprising: a display control unit (74) that performs control to display, on a display unit, first control of stopping the PBF-AM of all the shaped objects, second control of stopping the PBF-AM of shaped objects from which the defects have been detected and continuing the PBF-AM of remaining shaped objects, and third control of outputting a warning indicating that the defects have been detected as options for shaping control in a case where the sizes of the defects exceed the preset threshold value in the middle of the PBF-AM, wherein the shaping control unit (71) executes control of the selected option.
The information processing apparatus according to any one of claims 1 and 3 to 5, wherein in a case where the PBF-AM of the remaining shaped objects except for the shaped objects, from which the defects have been detected, is continued, the shaping control unit (71) determines, for the remaining shaped objects, a melting order by repeating processing of designating, as a shaped object to be melted next, a shaped object that is the furthest from a shaped object that is to be melted for a first time after the PBF-AM is continued and designating, as a shaped object to be melted next, a shaped object that is the furthest from a shaped object that is melted immediately before from among shaped objects for which orders of melting have not been designated.
The information processing apparatus according to claim 1, further comprising: a display control unit (74) that performs control to generate a result table including, for each of the shaped objects, information regarding defects detected for each of the layers on the basis of the layer data and information including a progress of PBF-AM processing on the shaped objects such that the result table is able to be displayed on a display unit, wherein the information including the progress of the PBF-AM processing includes either information indicating that the defects have occurred in the PBF-AM processing and information indicating that the PBF-AM processing has been performed normally.
The information processing apparatus according to claim 1, wherein the defect candidate specifying unit (72) measures an area of a defect candidate in an N-th layer (N is an integer that is equal to or greater than one) specified in the N-th layer and an area of a defect candidate in an N+1-th layer specified in the N+1-th layer from among the plurality of defect candidates overlapping in a plurality of layers that are adjacent in the stacking direction, calculates an overlapping area of an overlapping portion where the defect candidate in the N-th layer and the defect candidate in the N+1-th layer overlap in the stacking direction, and specifies that the defect candidate in the N-th layer and the defect candidate in the N+1-th layer are located at substantially the same position in a case where a ratio of the overlapping area to the area of the defect candidate in the N-th layer is same as or exceeds a first area threshold value and a ratio of the overlapping area to the area of the defect candidate in the N+1-th layer is same as or exceeds a second area threshold value.
The information processing apparatus according to claim 8, wherein the defect detection unit (73) merges the plurality of defect candidates determined to be located at substantially the same position in the stacking direction, measures a stacking direction length (Lz) of the merged defect candidate and a first direction length (Lx) and a second direction length (Ly) inside the layers intersecting the stacking direction of the merged defect candidate for each of the layers, and regards a maximum length out of the first direction length (Lx) and the second direction length (Ly) as a maximum layer length (Lxy).
The information processing apparatus according to claim 9, wherein the defect detection unit (73) prepares a maximum length threshold value in the stacking direction and a maximum layer length threshold value inside the layers and detects the merged defect candidate as the defect in a case where the stacking direction length (Lz) of the merged defect candidate is equal to or greater than the maximum length threshold value in the stacking direction and the maximum layer length (Lxy) inside the layers of the merged defect candidate is equal to or greater than the maximum layer length threshold value.
The information processing apparatus according to claim 9, wherein the defect detection unit (73) prepares a maximum length threshold value in the stacking direction and a maximum layer length threshold value inside the layers and detects the merged defect candidate as the defect in a case where the stacking direction length (Lz) of the merged defect candidate is equal to or greater than the maximum length threshold value in the stacking direction or the maximum layer length (Lxy) inside the layers of the merged defect candidate is equal to or greater than the maximum layer length threshold value.
A defect detection method performed by a defect candidate specifying unit (72), a defect detection unit (73), and a shaping control unit (71) included in an information processing apparatus, the method comprising: by the defect candidate specifying unit (72), detecting failure locations having occurred in layers, by which PBF-AM of shaped objects is performed, as defect candidates for each of the layers and specifying the plurality of defect candidates located at substantially same positions in the plurality of layers that are adjacent in a stacking direction on the basis of layer data obtained for each of the layers; by the defect detection unit (73), detecting defects remaining in the shaped objects on the basis of sizes of the plurality of defect candidates, which are located at substantially the same positions and are specified in the plurality of layers, in the stacking direction and the sizes thereof inside the layers; and by the shaping control unit (71), performing control to stop at least the PBF-AM of shaped objects from which the defects have been detected or to output a warning in a case where the sizes of the defects exceed a preset threshold value in a middle of the PBF-AM.
A three-dimensional PBF-AM apparatus comprising: a shaping plate (22) on which a powder bed to spread a powder material thereon is formed; a powder supply system (16) that spreads the powder material on the powder bed; a beam irradiation unit (2) that irradiates the powder material spread on the powder bed with a shaping beam; an electron optical system that performs scanning with the shaping beam in accordance with melting conditions for melting the powder material and melting the powder material spread on the powder bed; a defect candidate specifying unit (72) that detects failure locations having occurred in layers, by which PBF-AM of shaped objects is performed, as defect candidates for each of the layers and specifies the plurality of defect candidates located at substantially same positions in the plurality of layers that are adjacent in a stacking direction on the basis of layer data obtained for each of the layers; a defect detection unit (73) that detects defects remaining in the shaped objects on the basis of sizes of the plurality of defect candidates, which are located at substantially the same positions and are specified in the plurality of layers, in the stacking direction and the sizes thereof inside the layers; and a shaping control unit (71) that performs control to stop at least the PBF-AM of shaped objects from which the defects have been detected or to output a warning in a case where the sizes of the defects exceed a preset threshold value in a middle of the PBF-AM.

Description

BACKGROUND Technical Field The present invention relates to an information processing apparatus, a defect detection method, and a three-dimensional powder bed fusion additive manufacturing (PBF-AM) apparatus. Related Art In recent years, a three-dimensional powder bed fusion additive manufacturing (PBF-AM) technique in which layers obtained by thinly spreading a powder material of metal are layered one by one and are shaped has been in the limelight, and many types of three-dimensional PBF-AM techniques have been developed depending on differences in materials for the powder material and shaping methods. In a shaping method of a three-dimensional PBF-AM apparatus in the related art, a powder material is spread for each layer on a base plate placed on an upper surface of a stage, for example. Next, only a two-dimensional structural portion corresponding to one section of a shaped object of the powder material spread on the base plate is melted by a heating mechanism using an electron beam or a laser. Then, such layers of powder material are stacked one by one in the height direction (Z direction) to thereby form a shaped object. At the time of shaping each layer of the shaped object, a powder bed is formed on the base plate, and this shaping method is thus also referred to as a powder bed method. In the formation of the shaped object, the powder material cannot be completely melted at a part where a sintering failure has occurred, and irregularities occur on the surface of the shaped object in the middle of shaping. Since such irregularities may be defects, the three-dimensional PBF-AM apparatus performs defect detection on the basis of data acquired from the surface of the shaped object by performing camera imaging or back scattered electron (BSE) imaging. The camera imaging is, for example, a method of imaging the surface of the shaped object with visible light. The BSE imaging is a method of imaging the surface of the shaped object by detecting backscattered electrons of an electron beam with which the surface of the shaped object is irradiated. Layer data obtained by the camera imaging or the BSE imaging is displayed on a monitor as an XY sectional view per layer of the shaped object in the middle of the shaping. A user can check a state of the XY section immediately after the powder material is melted using the layer data. Furthermore, the user can also specify a location that may become a defect (referred to as a defect candidate) on the basis of the irregularities on the surface of the shaped object in the middle of the shaping. Examples of the defect candidate include an irregular part generated in the layers and a part insufficiently melted and having a space formed therein. As a technique related to such defect detection, a technique disclosed in Patent Literature 1 is known. Patent Literature 1 describes that "a determination unit calculates the height of a protrusion and at least either the total area of a region where the protrusion has been generated or the occupation ratio of the protrusion in a sintered region from a state of the protrusion measured by a surface state measurement unit and compares the calculated value with a corresponding threshold value to determine whether or not a shaped state of a sintered layer is satisfactory." Citation List Patent Literature Patent Literature 1: JP 2020-200501 A SUMMARY Even if the user can check the state of the XY section immediately after the melting for each layer using the defect detection function in the related art as described above, it is difficult for the user to visually check states of all the layers since PBF-AM for several hundreds to several thousands of layers is performed to complete a shaped object. Information necessary for defect detection cannot be obtained unless the shaped object is inspected by another measurement apparatus (for example, an apparatus using X-ray computed tomography (CT)) after the PBF-AM is completed. For this reason, it is not possible to know, until the PBF-AM is completed, whether or not a problematic defect has occurred during the PBF-AM. Also, the position of the defect, for example, is also not known as defect information according to the defect detection function in the related art. Under circumstances as described above, it has not been possible to prevent in advance a case where it is found that there is a problem in quality of a shaped object after the PBF-AM is performed over many days and the shaping is completed. In a case where a problem occurs in quality after completion of shaping, the user may lose great time and cost in the production process of the shaped object. The present invention has been made in view of such a situation, and an object thereof is to prevent a great loss of time and cost in a production process of a shaped object in advance. An information processing apparatus according to the present invention includes: a defect candidate specifying unit that detects failure locations hav