FR3148154A1 - Method for calibrating a fusion device comprising at least one beam emitter - Google Patents

Abstract

A method for calibrating a fusion device (1) comprising at least one beam emitter (2), such as a laser beam or an electron beam, said method comprising the following operations: a) using the fusion device (1) to locally scratch a test surface (95), moving the fusion device (1) and performing a scratching path (180) on the test surface (95), b) analyzing the scratching path (180) and determining the state of the fusion device (1) as a function of the analysis of the scratching path (180), wherein: the scratching path (180) comprises a plurality of distinct scratching sub-paths (182), the scratching sub-paths (182) each having the same pattern and being produced in a plurality of distinct local test sub-areas (190) in the test surface (95), and operation b) comprises analyzing each scratch sub-path (182). Figure for abstract: Figure 3

Description

Method for calibrating a fusion device comprising at least one beam emitter Disclosure area

The present disclosure relates to a method of calibrating a fusion device comprising at least one beam emitter, such as a laser beam or an electron beam.

In particular, it is known to use a melting device for the manufacture of metal parts by selective melting of a powder using a beam emitter, such as a laser beam or an electron beam.

Such a process is called in particular "Direct Metal Laser Sintering", "Selective Laser Melting" or "Electron Beam Melting" and described in particular in document FR 2 981 867 A1. This process makes it possible to manufacture metal parts used in particular in aircraft turbojets, in particular turbojet turbines.

State of the art

The present disclosure aims to calibrate such a fusion device on the manufacturing surface or a representative surface of the manufacturing plate, so as on the one hand to make it operate as satisfactorily as possible and on the other hand to identify when the fusion device is not operating correctly.

The present disclosure aims to propose a calibration method requiring a limited time to carry it out (not exceeding a few hours, ideally of the order of one to two hours) and which is not specific to the manufacture of a particular part, but on the contrary can be identical for all the fusion devices used in a company.

Disclosure Statement

To address the above problems, according to the disclosure, said method comprises a calibration test comprising the following operations:

(a) using the fusion device to locally scrape (i.e., remove a coating thickness) a test surface and performing a calibration test, the calibration test comprising moving the fusion device and performing a scraping path on the test surface,

b) analysis of the scraping path carried out during operation a) and determination of the state of the fusion device based on the analysis of the scraping path,

in which:

the scratching path comprises a plurality of distinct scratching sub-paths, the scratching sub-paths each having the same pattern and being made into a plurality of distinct local test sub-areas in the test surface, and

operation b) includes the analysis of each scraping sub-path.

Thus, each scratching sub-path constitutes a standard test of the so-called "firing" accuracy of the beam emitter. Performing this standard test multiple times reduces the cost and time of execution and analysis over the entire test surface, while having the test surface as large as possible, i.e. over at least the essential (major part) of the surface that the fusion device can cover.

By "each presenting the same pattern" it should be understood that the scratching sub-paths are preferably identical, but they may in particular present a different scale (be of different sizes) or a different orientation.

Operation b) may be carried out visually and/or with optical means to improve the accuracy of the analysis.

According to another characteristic in accordance with the disclosure, the scratching path carried out during operation a) preferably comprises between 250 and 2000 scratching sub-paths per square meter carried out in a plurality of distinct local test sub-zones.

According to another feature in accordance with the present disclosure, preferably performing the calibration test comprises performing a focusing test, the fusion device has a focusing point and the focusing test comprises, during operation a), a plurality of focusing sub-operations in each local test sub-area, during the performance of each focusing sub-operation the fusion device is placed at a test distance from the test surface and a focusing portion of the scratching sub-path is performed, the focusing point being offset by a distance increment between the focusing sub-operations, and operation b) comprises measuring the width of each focusing portion (perpendicular to the movement) of the scratching sub-path.

This determines the positioning of the beam emitter's focal point for the entire test surface.

According to a feature consistent with the present disclosure, preferably the focusing portions comprise:

a portion of theoretical underfocusing carried out with the focus point theoretically located on the test surface (95),

at least a portion of theoretical underfocusing achieved with the focus point located back from the test surface (95), and

at least one portion of overfocusing achieved with the focus point located beyond the test surface (95).

Thus, the correction to be made to the distance between each beam emitter and the test surface can easily be determined during operation b). The term "theoretically" means "if the fusion device had no defect".

In various embodiments of the method according to the disclosure, one and/or the other of the following provisions may optionally be further used:

- the distance increment between focusing sub-operations is equal to a quarter of the Rayleigh length;

- operation a) includes making a line for each portion of focus.

According to another characteristic in accordance with the present disclosure, preferably the performance of the calibration test comprises the performance of a dynamic test, the dynamic test comprises during operation a) a dynamic sub-operation for the performance of each scratching sub-path, the dynamic sub-operation comprises the performance of a dynamic portion of the scratching sub-path, the dynamic portion comprises a closed shape.

Thus, the dynamics of the beam emitting device can be managed and the uncertainty in the positioning of the beam emitted by each beam emitter can be determined. More precisely, the consistency between the movement speed, acceleration, start of emission and end of emission for each beam emitter can be determined.

In various embodiments of the method according to the disclosure, one and/or the other of the following provisions may optionally be further used:

- during operation b), an initial end and a final end are identified on the dynamic portion produced and the distance between the initial end and the final end is determined;

- the closed shape is a circle and in operation b), we determine the circularity, the position of the center and/or the diameter of the circle.

According to another feature in accordance with the present disclosure, preferably performing the calibration test comprises performing a relative positioning test, the relative positioning test includes during operation a) a relative positioning sub-operation for the realization of each scraping sub-path, the relative positioning sub-operation includes the realization of a first portion of relative positioning of the scratching sub-path and the realization of a second portion of relative positioning of the scratching sub-path, and during operation b), the positioning of the first portion of relative positioning relative to the second portion of relative positioning is analyzed.

According to an additional characteristic of the present disclosure, preferably the first portion of relative positioning of the scratching sub-path is carried out with a first beam emitter and the second portion of relative positioning of the scratching sub-path is carried out with a second beam emitter distinct from the first beam emitter.

This improves the management of multi-laser interaction.

According to a further feature of the present disclosure, preferably the relative positioning test comprises a concentricity test, the first portion of relative positioning comprises at least two first concentricity lines defining a first point of intersection, the second portion of relative positioning comprises at least two second concentricity lines defining a second point of intersection, and in operation b), the distance between the first point of intersection and the second point of intersection is determined.

Thus, the offset (concentricity defect) between the first beam emitter and the second beam emitter along the two directions of the test surface is determined.

In various embodiments of the method according to the disclosure, one and/or the other of the following provisions may optionally be further used:

- the first two concentricity lines form a first cross, each first concentricity line comprising two first half concentricity lines between which the first point of intersection is located, and the second two concentricity lines form a second cross, each second concentricity line comprising two second half concentricity lines between which the second point of intersection is located;

- the first half-concentricity lines of each first concentricity line are spaced apart from each other and the second half-concentricity lines of each second concentricity line are spaced apart from each other;

the second cross is angularly offset from the first cross.

According to an additional or alternative feature in accordance with the present disclosure, preferably the relative positioning test comprises an adjacency test, the first relative positioning portion comprises a first adjacency line, the second relative positioning portion comprises a second adjacency line having a proximal end located near the first adjacency line, and during operation b), the distance between the middle of the first adjacency line and the proximal end of the second adjacency line is determined.

According to another characteristic in accordance with the present disclosure, the method preferably has the following characteristics:

the method includes carrying out an overall concentricity test,

the overall concentricity test includes an operation c), operation c) comprises performing a first overall scratch circle on the test surface and a second overall scratch circle on the test surface, several local test sub-areas among the plurality of distinct local test sub-areas are arranged between the first overall scratch circle and the second overall scratch circle, and

the overall concentricity test includes an operation d), operation d) includes determining the circularity, center position or diameter of each of the first overall scraping circle or the second overall scraping circle and/or concentricity of the first overall scraping circle and the second overall scraping circle.

According to an additional characteristic, preferably operation c) comprises the use of the first beam emitter and the movement of the first beam emitter to achieve at least in part the first overall scratching circle on the test surface, operation c) comprises the use of the second beam emitter and the movement of the second beam emitter to achieve at least in part the second overall scratching circle on the test surface.

According to another feature in accordance with the present disclosure, a plate having a flat surface and a coating covering the flat surface is preferably used, the test surface extending into the coating.

This prevents the filler material from influencing the test, as filler material has characteristics that can fluctuate and influence the scraping path. The coating surface is completely removed by scraping to reveal the plaque or its appearance is modified by scraping.

In various embodiments of the method according to the disclosure, one and/or the other of the following provisions may optionally be further used:

- the coating consists of anodization;

- the coating consists of a photosensitive sheet;

- the plate is made of aluminum:

- the plate is made of glass:

- during operation b), the state of the transmitter is determined by comparing the scratch pattern made with the test pattern;

- in operation a), the sub-pattern is repeated in a disjoint manner, the sub-zones being spaced apart from each other.

Brief description of the figures

Other features and advantages of the present disclosure will become apparent from the following detailed description, with reference to the accompanying drawings in which:

represents a fusion device comprising several beam emitters for scratching a test surface,

represents a scraping path performed by the merging device, the scraping path comprising a plurality of scraping sub-paths,

represents on an enlarged scale one of the scraping sub-paths carried out by the fusion device,

represents on an enlarged scale the area marked IV at ,

represents on an enlarged scale the area marked V at the and the determination of a first point of intersection,

represents on an enlarged scale the area marked V at the and the determination of a second point of intersection,

represents on an enlarged scale the area marked V at the and the determination of a third point of intersection,

represents on an enlarged scale the area marked V at the and the determination of a fourth point of intersection,

represents on an enlarged scale the area marked VI at ,

represents on an enlarged scale the area marked VII in the .

Detailed Description of Disclosure

There illustrates a fusion device 1 and a plate 90 covered with a coating 94.

The melting device 1 comprises a first beam emitter 2, a second beam emitter 4, a third beam emitter 6 and a fourth beam emitter 8. Each of the first beam emitter 2, the second beam emitter 4, the third beam emitter 6 and the fourth beam emitter 8 is capable of generating a laser beam or an electron beam having a focal point, so as to scrape a metal powder to produce a part layer by layer, as described in particular in document FR 2 981 867 A1.

The fusion device 1 further comprises a first actuator 3 for orienting and/or moving the first beam emitter 2, a second actuator 5 for orienting and/or moving the second beam emitter 4, a third actuator 7 for orienting and/or moving the third beam emitter 6 and a fourth actuator 9 for orienting and/or moving the fourth beam emitter 8. The first actuator 3, the second actuator 5, the third actuator 7 and the fourth actuator 9 are independent of each other and make it possible to orient and/or move the first beam emitter 2, the second beam emitter 4, the third beam emitter 6 and the fourth beam emitter 8 independently of each other.

The first beam emitter 2, the first actuator 3, the second beam emitter 4, the second actuator 5, the third beam emitter 6, the third actuator 7, the fourth beam emitter 8 and the fourth actuator 9 are controlled by a control device 100 for coordinating the different actions.

The plate 90 has a flat surface 92. A coating 94 covers the flat surface 92. The coating 94 preferably comprises an anodizing deposit. Alternatively, the coating 94 could in particular be a photosensitive sheet.

The plate 90 is preferably made of aluminum. Alternatively, the plate 90 could be made of glass.

In order to calibrate the fusion device 1, a calibration test is carried out. The calibration test essentially comprises an operation a) of scraping and an operation b) of analysis.

In the scratching operation a), the first beam emitter 2, the second beam emitter 4, the third beam emitter 6 and/or the fourth beam emitter 8 are used in order to scratch a test surface 95 and to carry out a scratching path 180 on the test surface 95. The test surface 95 has a thickness of a few microns to a few tens of microns. In the illustrated embodiment, the test surface 95 is formed by the coating 94. The scratching path 180 is characterized by the absence (at least partial) of the coating 94, destroyed locally by exposure to the laser beam or the electron beam of one of the emitters. Each of the first beam emitter 2, the second beam emitter 4, the third beam emitter 6 and the fourth beam emitter 8 is capable of generating a laser beam or an electron beam has a focusing point.

The test surface 95 extends in a first direction X and a second direction Y, perpendicular to the first direction X. A third direction Z extends perpendicular to the first direction X and to the second direction Y, in other words perpendicular to the test surface 95.

The laser beam or electron beam emitted by the first beam emitter 2, the second beam emitter 4, the third beam emitter 6 and the fourth beam emitter 8 extends substantially along the third direction Z.

The first actuator 3, the second actuator 5, the third actuator 7 and the fourth actuator 9 are able to move respectively the first beam emitter 2, the second beam emitter 4, the third beam emitter 6 and the fourth beam emitter 8 either only in translation along the first direction X and/or the second direction Y, or in rotation about axes parallel to the first direction X and to the second direction Y and in translation at least partly along the third direction Z. The first actuator 3, the second actuator 5, the third actuator 7 and the fourth actuator 9 are therefore able to act along several axes. The control device 100 coordinates the movements in order to maintain a substantially constant test distance D, or at least to maintain the focal point on the test surface, unless otherwise indicated below, between on the one hand the test surface 95 and on the other hand the first actuator 3, the second actuator 5, the third actuator 7 and the fourth actuator 9. Of course, as a variant, other combinations of movements than those mentioned above can be carried out. In particular, it may be provided that the first actuator 3, the second actuator 5, the third actuator 7 and the fourth actuator 9 are capable of respectively moving the first beam emitter 2, the second beam emitter 4, the third beam emitter 6 and the fourth beam emitter 8 in rotation about two perpendicular axes, in particular one parallel to the first direction X and the other parallel to the second direction Y and in translation at least partly along the third direction Z. In addition, the fusion device 1 comprises a first focusing lens, a second focusing lens, a third focusing lens and a fourth focusing lens acting respectively on the beams emitted respectively by the first actuator 3, the second actuator 5, the third actuator 7 and the fourth actuator 9 in order to keep them focused on the test surface 95, in other words to maintain their focal point on the test surface. For this purpose, the first focusing lens, the second focusing lens, the third focusing lens and the fourth focusing lens may in particular be movable in translation, in order to vary their distance relative to the first actuator 3, the second actuator 5, the third actuator 7 and the fourth actuator 9 respectively or be deformable in order to vary their curvature. The control device 100 then coordinates the translation or the variation in curvature of each focusing lens with the control of the respective actuator in order to adjust the focusing position.

As illustrated in the , in the embodiment described, the scratching path 180 comprises a plurality of scratching sub-paths 182. The scratching sub-paths 182 all have the same pattern and are each carried out in a local test sub-area 190. The test surface 95 therefore comprises a plurality of distinct local test sub-areas 190.

The scratch path 180 has (and therefore the test surface 95) a symmetry with respect to a median plane perpendicular to the first direction X and also a symmetry with respect to a median plane perpendicular to the second direction Y. The scratch path 180 even has an angular repetition of 90 degrees around an axis extending along the third direction Z and passing through a central point.

In the illustrated embodiment, the scratching sub-paths 182 are identical, schematically they are simply offset relative to each other along the first direction X and/or the second direction Y. Alternatively, the scratching sub-paths 182 could have different sizes, for example smaller near the central point and larger away from the central point. They could also have a rotation about an axis extending along the third direction Z relative to each other.

The calibration test includes a focus test, a dynamic test, and a relative positioning test. The relative positioning test includes a concentricity test and an adjacency test.

The calibration test is performed in each focusing sub-zone 150. More specifically, each local test sub-zone 190 comprises four focusing sub-zones 150, each of the first fusion emitter 2, the second fusion emitter 4, the third fusion emitter 6 and the fourth fusion emitter 8 being used in one and only one of the four focusing sub-zones 150 of each local test sub-zone 190.

There illustrates the scratching sub-path 182 in one of the focusing sub-areas 150 in which the first fusion emitter 2 is used.

The focusing test comprises performing a theoretical focusing portion 151 performed with the first fusion emitter 2 by controlling the test distance D so that it corresponds to a theoretical focusing distance of the first fusion emitter 2. The theoretical focusing distance is provided by the manufacturer of the first fusion emitter 2. Alternatively, the theoretical focusing distance may be determined by performing tests consisting of moving the first fusion emitter in order to have the focusing point which coincides with the test surface 95 at the center (along the first direction X and the second direction Y) of the test surface 95.

The focusing test comprises, in each focusing sub-area 150, during the scratching operation a), performing a focusing sub-operation in each focusing sub-area 150. Each focusing sub-operation comprises performing a first theoretical sub-focusing portion 152a, a second theoretical sub-focusing portion 153a, a third theoretical sub-focusing portion 154a, a fourth theoretical sub-focusing portion 155a and a fifth theoretical sub-focusing portion 156a by reducing the test distance D, or at least by moving the focusing point along the third direction, by increments of one quarter of the Rayleigh length (generally abbreviated to the symbol Zr) relative to the theoretical focusing distance for the first theoretical sub-focusing portion 152a and between each theoretical sub-focusing portion 153a and the fifth theoretical sub-focusing portion 154a. following theoretical underfocusing. The focusing test further comprises, in each focusing sub-zone 150, during the focusing sub-operation, performing a first theoretical overfocusing portion 152b, a second theoretical overfocusing portion 153b, a third theoretical overfocusing portion 154b, a fourth theoretical overfocusing portion 155b and a fifth theoretical overfocusing portion 156b by increasing the test distance D, or at least by moving the focusing point along the third direction, by the increment of a quarter of the Rayleigh length length relative to the theoretical focusing distance for the first theoretical overfocusing portion 152b and between each underfocusing portion for the following underfocusing portions. Thus, it is carried out according to the principle of the measurement methodology of ISO11146-3.

Of course, the order of execution is not essential, it is also possible to start with the fifth theoretical underfocus portion 156a by setting the test distance D to the theoretical focusing distance minus five-quarters of the Rayleigh length, or at least by moving the focus point so that it is theoretically five-quarters of the Rayleigh length back (above) the test surface 95 and to increase the test distance by the increment of one-quarter of the Rayleigh length to end with the fifth theoretical overfocus portion 156b with the test distance D equal to the theoretical focusing distance plus five-quarters of the Rayleigh length, or at least by moving the focus point so that it is theoretically five-quarters of the Rayleigh length beyond (below) the test surface 95, or to proceed in the opposite direction.

In the illustrated embodiment, the theoretical focusing portion 151, each of the theoretical underfocusing portions 152a, 153a, 154a, 155a, 156a and each of the theoretical overfocusing portions 152b, 153b, 154b, 155b, 156b form parallel lines arranged side-by-side and spaced apart from each other, in the manner of a bar code.

In analysis operation b), the focusing test includes measuring the width L, perpendicular to the elongation of the line, of the theoretical focusing portion 151, of each of the theoretical under-focusing portions 152a, 153a, 154a, 155a, 156a and of each of the theoretical over-focusing portions 152b, 153b, 154b, 155b, 156b.

Schematically, for each focusing sub-zone 150, the smallest width L corresponds to a real focusing distance and must be obtained when the test distance D is equal to the theoretical focusing distance, or at least when the focusing point is on the test surface 95. In other words, the theoretical focusing portion 151 must have the smallest width L. If one of the fusion emitters has the smallest width L when the test distance D has a substantially constant offset relative to the theoretical focusing distance 151 for all the focusing sub-zones 150, the calibration of the fusion emitter must be modified accordingly. If one of the fusion emitters has the smallest width L for values of test distance D varying according to the focusing sub-zones 150, this fusion emitter must be revised or replaced.

A more advanced analysis consists, for each focusing sub-zone 150, in not simply seeking to determine which portion has the smallest width L among the theoretical focusing portion 151, the theoretical under-focusing portions 152a, 153a, 154a, 155a, 156a and the theoretical over-focusing portions 152b, 153b, 154b, 155b, 156b as indicated above, but in taking into account the width of all (eleven in the illustrated embodiment) the portions to determine the focusing point, in particular by assuming a Gaussian beam, then in determining the gap between the focusing point and the test surface 95.

The calibration test is carried out analogously with the second fusion emitter 4, the third fusion emitter 6 and the fourth fusion emitter 8 in the respective other focusing sub-areas 150 and repeated in each local test sub-area 190. Consequently, the focusing test allows an analysis over the entire test surface 95.

As illustrated in the , the dynamic test comprises during the fusion operation a), the realization in each local test sub-zone 190 of a dynamic sub-operation in a closed path sub-zone 160 to form a dynamic portion of the scratching sub-path 182. Each closed path sub-zone 160 extends around the focusing sub-zones 150. Each dynamic sub-operation comprises the realization of a first circle 161 between a first initial end 161a and a first final end 161b with the first fusion emitter 2, of a second circle 162 between a second initial end 162a and a second final end 162b with the second fusion emitter 4, of a third circle 163 between a third initial end 163a and a third final end 163b with the third fusion emitter 6 and of a fourth circle 16 between a fourth initial end 164a and a fourth final end 164b with the fourth fusion emitter 8.

In the analysis operation b), the dynamic test comprises, for each closed path sub-zone 160, determining the distance between the first initial end 161a and the first final end 161b, determining the distance between the second initial end 162a and the second final end 162b, determining the distance between the third initial end 163a and the third final end 163b, determining the distance between the fourth initial end 164a and the fourth final end 164b and/or determining the circularity, the position of the center or the diameter of the first circle 161, the second circle 162, the third circle 163 and the fourth circle 164.

The state of each beam emitter can also be determined absolutely for the determination of circularity or the distance between the initial end and the final end if this distance should be zero, relatively by comparison of the position of the center and the diameter of each of the circles, but it can also be determined by comparison with a test pattern.

The relative positioning test comprises, during the scratching operation a), the performance in each local test sub-zone 190 of a relative positioning sub-operation. The relative positioning sub-operation comprises a concentricity sub-operation, in a concentricity sub-zone 170, more precisely in four concentricity sub-zones 170 per local test sub-zone 190 in the illustrated embodiment.

Each dynamic positioning sub-operation comprises producing with the first fusion emitter 2 a first concentricity line 171 comprising two first concentricity half-lines 171a, 171b spaced apart from each other and another first concentricity line 176 also comprising two first concentricity half-lines 176a, 176b spaced apart from each other. The first two concentricity lines 171, 176 are angularly offset by 90 degrees and form a first cross. As illustrated in , during operation b) of analyzing the concentricity test, a first point of intersection 175a is determined corresponding to the intersection of the first two concentricity lines 171, 176. The first point of intersection 175a is located between the first two concentricity half-lines 171a, 171b and between the first two concentricity half-lines 176a, 176b.

Each dynamic positioning sub-operation further comprises producing with the second fusion emitter 4 a second concentricity line 172 comprising two second concentricity half-lines 172a, 172b spaced apart from each other and another second concentricity line 177 also comprising two second concentricity half-lines 177a, 177b spaced apart from each other. The two second concentricity lines 172, 177 are angularly offset by 90 degrees and form a second cross. As illustrated in , during operation b) of analyzing the concentricity test, a second point of intersection 176a is determined corresponding to the intersection of the two second concentricity lines 172, 177. The second point of intersection 175b is located between the two second concentricity half-lines 172a, 172b and between the two second concentricity half-lines 177a, 177b.

Each dynamic positioning sub-operation further comprises producing with the third fusion emitter 6 a third concentricity line 173 comprising two third concentricity half-lines 173a, 173b spaced apart from each other and another third concentricity line 178 also comprising two third concentricity half-lines 178a, 178b spaced apart from each other. The two third concentricity lines 173, 178 are angularly offset by 90 degrees and form a third cross. As illustrated in , during operation b) of analyzing the concentricity test, a third point of intersection 175c is determined corresponding to the intersection of the two third concentricity lines 173, 178. The third point of intersection 175c is located between the two third concentricity half-lines 173a, 173b and between the two third concentricity half-lines 178a, 178b.

Each dynamic positioning sub-operation further comprises producing with the fourth fusion emitter 8 a fourth concentricity line 174 comprising two third concentricity half-lines 174a, 174b spaced apart from each other and another fourth concentricity line 179 also comprising two fourth concentricity half-lines 179a, 179b spaced apart from each other. The two fourth concentricity lines 174, 179 are angularly offset by 90 degrees and form a fourth cross. As illustrated in , during operation b) of analyzing the concentricity test, a fourth point of intersection 175d is determined corresponding to the intersection of the two fourth concentricity lines 174, 179. The fourth point of intersection 175d is located between the two fourth concentricity half-lines 174a, 174b and between the two fourth concentricity half-lines 179a, 179b.

The first cross, second cross, third cross and fourth cross have a regular angular offset of about 22.5 degrees relative to each other. The amount of angular offset depends on the number of crosses.

In analysis operation b), the concentricity test comprises, for each concentricity sub-zone 170, the determination of the distance between the first point of intersection 175a, the second point of intersection 175b, the third point of intersection 175c and the fourth point of intersection 175d.

Instead of being determined relatively, the state of the transmitter can also be determined absolutely for the concentricity test, by comparing (determining the deviation) the first intersection point 175a, the second intersection point 175b, the third intersection point 175c and the fourth intersection point 175d with a test pattern comprising the location of a theoretical center, for the entire test surface 95.

As illustrated in the , the adjacency test comprises, during the scratching operation a), the performance in each local test sub-zone 190 of an adjacency sub-operation in an adjacency sub-zone 110 to form adjacency portions of the scratching sub-path 182. Each adjacency sub-operation comprises the performance of a first relative positioning portion forming a central square. The first relative positioning portion comprises a first adjacency line 115 performed with the first fusion emitter 2, a first adjacency line 125 performed with the second fusion emitter 4, a first adjacency line 135 performed with the third fusion emitter 6 and a first adjacency line 145 performed with the fourth fusion emitter 8.

Each adjacency sub-operation further comprises performing second relative positioning portions 102a, 102b, 104a, 104b, 106a, 106b, 108a, 108b formed by eight external square portions.

The second relative positioning portion 102a and the second relative positioning portion 102b are produced with the first fusion emitter 2. The second relative positioning portion 102a comprises a second adjacency line 111a having a proximal end 111 located near the first adjacency line 115, the second adjacency line 111a extending substantially perpendicular to the first adjacency line 115 from the proximal end 111. The second relative positioning portion 102a further comprises a second adjacency line 141a having a proximal end 141 located near the first adjacency line 145, the second adjacency line 141a extending substantially perpendicular to the first adjacency line 145 from the proximal end 141.

The second relative positioning portion 102b comprises a second adjacency line 131a having a proximal end 131 located near the third adjacency line 135, the second adjacency line 131a extending substantially perpendicular to the first adjacency line 135 from the proximal end 131. The second relative positioning portion 102b further comprises a second adjacency line 121a having a proximal end 121 located near the first adjacency line 125, the second adjacency line 121a extending substantially perpendicular to the first adjacency line 125 from the proximal end 121.

The second relative positioning portion 104a and the second relative positioning portion 104b are produced with the second fusion emitter 4. The second relative positioning portion 104a comprises a second adjacency line 112a having a proximal end 112 located near the first adjacency line 115, the second adjacency line 112a extending substantially perpendicular to the first adjacency line 115 from the proximal end 112. The second relative positioning portion 104a further comprises a second adjacency line 142a having a proximal end 142 located near the first adjacency line 145, the second adjacency line 142a extending substantially perpendicular to the first adjacency line 145 from the proximal end 142.

The second relative positioning portion 104b comprises a second adjacency line 132a having a proximal end 132 located near the third adjacency line 135, the second adjacency line 132a extending substantially perpendicular to the first adjacency line 135 from the proximal end 132. The second relative positioning portion 104b further comprises a second adjacency line 122a having a proximal end 122 located near the first adjacency line 125, the second adjacency line 122a extending substantially perpendicular to the first adjacency line 125 from the proximal end 122.

The second relative positioning portion 106a and the second relative positioning portion 106b are produced with the third fusion emitter 6. The second relative positioning portion 106a comprises a second adjacency line 123a having a proximal end 123 located near the first adjacency line 125, the second adjacency line 123a extending substantially perpendicular to the first adjacency line 125 from the proximal end 123. The second relative positioning portion 106a further comprises a second adjacency line 113a having a proximal end 113 located near the first adjacency line 115, the second adjacency line extending 113a substantially perpendicular to the first adjacency line 115 from the proximal end 113.

The second relative positioning portion 106b comprises a second adjacency line 143a having a proximal end 143 located near the first adjacency line 145, the second adjacency line 143a extending substantially perpendicular to the first adjacency line 145 from the proximal end 143. The second relative positioning portion 106b further comprises a second adjacency line 133a having a proximal end 133 located near the first adjacency line 135, the second adjacency line 133a extending substantially perpendicular to the first adjacency line 135 from the proximal end 133.

The second relative positioning portion 108a and the second relative positioning portion 108b are made with the fourth fusion emitter 8. The second relative positioning portion 108a comprises a second adjacency line 124a having a proximal end 124 located near the first adjacency line 125, the second adjacency line 124a extending substantially perpendicular to the first adjacency line 125 from the proximal end 124. The second relative positioning portion 108a further comprises a second adjacency line 114a having a proximal end 114 located near the first adjacency line 115, the second adjacency line 114a extending substantially perpendicular to the first adjacency line 115 from the proximal end 114.

The second relative positioning portion 108b comprises a second adjacency line 144a having a proximal end 144 located near the first adjacency line 145, the second adjacency line 144a extending substantially perpendicular to the first adjacency line 145 from the proximal end 144. The second relative positioning portion 108b further comprises a second adjacency line 134a having a proximal end 134 located near the first adjacency line 135, the second adjacency line 134a extending substantially perpendicular to the first adjacency line 135 from the proximal end 134.

The adjacent test comprises during operation b) determining the distance d between the middle of each first adjacency feature 115, 125, 135, 145 and the proximal end 111, 112, 113, 114; 124, 123, 122, 121; 131, 132, 133, 134; 144, 143, 142, 141 of the corresponding second adjacency feature 111a, 112a, 113a, 114a; 124a, 123a, 122a, 121a; 131a, 132a, 133a, 134a; 144a, 143a, 142a, 141a. As illustrated in the in relation to the first adjacency line 115 and the second adjacency line 112a, the distance d is measured between the middle of the first adjacency line 115 and the proximal end of the second adjacency line 112a.

As illustrated in the , the test surface 95 preferably comprises between 250 and 2000 disjointed local test sub-areas 190 per square meter, more precisely one hundred and nine local test sub-areas 190 in the illustrated embodiment, the test surface 95 forming a square with sides of 400 millimeters. The scratching path 180 therefore comprises one hundred and nine scratching sub-paths 182.

The calibration test further includes a global concentricity test. Unlike the tests previously described, the concentricity test is not limited to each local test sub-zone 190 and does not extend to each local test sub-zone 190.

The scratching path 180 comprises, in addition to the aforementioned scratching sub-paths 182, the production during an operation c) of a first global circle 191, a second global circle 192 and a third global circle 193. Each of the first global circle 191, second global circle 192 and third global circle 193 is produced in four successive parts (each representing a quarter circle) with the first fusion emitter 2, the second fusion emitter 4, the third fusion emitter 6 and the fourth fusion emitter 8.

Local test sub-areas 190 are arranged within the first global circle 191, between the first global circle 191 and the second global circle 192, and between the second global circle 192 and the third global circle 193.

An operation d) of the overall concentricity test comprises determining the circularity, center position and/or diameter of each of the first overall scraping circle 191, the second overall scraping circle 192 and the third overall scraping circle 193 and/or concentricity of the first overall scraping circle 191, the second overall scraping circle 192 and the third overall scraping circle 193.

Claims (10)

Method for calibrating a fusion device (1) comprising at least one beam emitter (2), such as a laser beam or an electron beam, said method comprises a calibration test comprising the following operations:
a) using the fusion device (1) to locally scratch a test surface (95) and performing a calibration test, the calibration test comprising moving the fusion device (1) and performing a scratching path (180) on the test surface (95),
b) analysis of the scraping path (180) carried out during operation a) and determination of the state of the fusion device (1) based on the analysis of the scraping path (180),
in which:
the scratching path (180) comprises a plurality of distinct scratching sub-paths (182), the scratching sub-paths (182) each having the same pattern and being made in a plurality of distinct local test sub-areas (190) in the test surface (95), and
operation b) includes the analysis of each scraping sub-path (182). A calibration method according to claim 1 wherein performing the calibration test comprises performing a focusing test, the fusion device (1) has a focusing point and the calibration test comprises:
- during operation a), a plurality of focusing sub-operations in each local test sub-area (190), when performing each focusing sub-operation the fusion device (1) is placed at a test distance (D) from the test surface (95) and a focusing portion (151, 152a to 156a, 152b to 156b) of the scratching sub-path (182) is performed, the focusing point being shifted by a distance increment between the focusing sub-operations, and
- operation b) comprises measuring the width (L) of each focusing portion (151, 152a to 156a, 152b to 156b) of the scratching sub-path (182). Calibration method according to the preceding claim in which the focusing portions comprise:
a theoretical focusing portion (151) made with the focusing point theoretically located on the test surface (95),
at least one portion of theoretical underfocusing (152a to 156a) achieved with the focusing point located behind the test surface (95), and
at least one portion of theoretical overfocusing (152b to 156b) achieved with the focal point located beyond the test surface (95). Calibration method according to any one of the preceding claims, in which carrying out the calibration test comprises carrying out, during operation a), a dynamic test, the dynamic test comprises a dynamic sub-operation for carrying out each scratching sub-path (182), the dynamic sub-operation comprises carrying out a dynamic portion of the scratching sub-path, the dynamic portion comprises a closed shape (161, 162, 163, 164). Method according to the preceding claim, in which during operation b), an initial end and a final end are identified on the dynamic portion produced and the distance between the initial end (161a, 162a, 163a, 164a) and the final end (161b, 162b, 163b, 164b) is determined. A calibration method according to any preceding claim wherein performing the calibration test comprises performing a relative positioning test, the relative positioning test understand :
- during operation a), a relative positioning sub-operation for the realization of each scraping sub-path (182), the relative positioning sub-operation comprises performing a first relative positioning portion (115; 171, 176) of the scratching sub-path and performing a second relative positioning portion (112a; 172, 177) of the scratching sub-path, is
- during operation b), the positioning of the first relative positioning portion (115; 171, 176) relative to the second relative positioning portion (112a; 172, 177) is analyzed. Calibration method according to the preceding claim in which the first relative positioning portion (115; 171, 176) of the scratching sub-path is carried out with a first beam emitter (2) and the second relative positioning portion (112a; 172, 177) of the scratching sub-path is carried out with a second beam emitter (4) distinct from the first beam emitter (2). Calibration method according to the preceding claim in which:
The relative positioning test includes a concentricity test,
the first portion of relative positioning comprises at least two first concentricity lines (171, 176) defining a first point of intersection (175a),
the second portion of relative positioning comprises at least two second concentricity lines (172, 177) defining a second point of intersection (175b), and
in operation b), the distance between the first point of intersection (175a) and the second point of intersection (175b) is determined. Calibration method according to any one of claims 6 to 8 in which:
the relative positioning test includes an adjacency test,
the first relative positioning portion comprises a first adjacency feature (115),
the second relative positioning portion comprises a second adjacency line (112a) having a proximal end (112) located near the first adjacency line (115), and
in operation b), the distance (d) between the middle of the first adjacency line (115) and the proximal end (112) of the second adjacency line (112a) is determined. A method according to any preceding claim wherein:
the method includes carrying out an overall concentricity test,
the overall concentricity test includes an operation c), operation c) comprises making a first overall scratch circle (191) on the test surface (95) and a second overall scratch circle (192) on the test surface (95), several local test sub-areas (190) among the plurality of distinct local test sub-areas (190) are arranged between the first overall scratch circle (191) and the second overall scratch circle (192), and
the overall concentricity test includes an operation d), operation d) comprises determining the circularity, center position or diameter of each of the first overall scraping circle (191) or the second overall scraping circle (192) and/or concentricity of the first overall scraping circle (191) and the second overall scraping circle (192).