JP2020094269A - Additive manufacturing apparatus - Google Patents

Abstract

To provide an additive manufacturing apparatus capable of adding a high-accuracy molded article.SOLUTION: An additive manufacturing apparatus 100 adds a molded article to a base B by using a powder material or a linear material, and the apparatus includes: an additive material supply unit 110; a light irradiation unit 120; and a control unit 130 that controls the supply of a first powder material P1 and relative scanning of a light beam with respect to the base B. The light irradiation unit 120 has a central light beam irradiation unit 121 and an outside light beam irradiation unit 123. The control unit 130 independently controls the output conditions for the central light beam irradiation unit 121 and the output conditions for the outside light beam irradiation unit 123, and thereby increases a peak LCP3 in the beam profile of the power density of a central light beam LC than a peak LSP3 in the beam profile of the power density of an outside light beam LS so as to add a molded article FF.SELECTED DRAWING: Figure 1

Description

The present invention relates to an additive manufacturing device.

As described in Patent Document 1, the LMD (Laser Metal Deposition) method applied to an additive manufacturing apparatus irradiates a laser beam while spraying and supplying a powder material of the same kind or different kinds of metal to a metal base. Then, it is used as a build-up technique (partial control of physical properties) in which a powder material is melted and then solidified to add a modeled object to a base. The LMD method can adjust and supply the component ratios of a plurality of powder materials, which is difficult with the SLM (Selective Laser Melting) method, has a high degree of freedom in shape as compared with the SLM method, and is capable of approximately 5-10 times high-speed modeling. is there.

JP, 2005-196265, A

In the LMD method, for example, when a hard shaped article made of tungsten carbide (WC) or the like is added to a base made of carbon steel (S45C), spatter may occur during rapid heating, and cracks may occur during rapid solidification. This may occur, and the quality of the hard shaped object deteriorates.

It is an object of the present invention to provide an additional manufacturing apparatus that can add a high-quality shaped object.

(1. First mode of additional manufacturing apparatus)
An additional manufacturing apparatus according to a first aspect of the present invention is an additional manufacturing apparatus that adds a modeled object to a base using a powder material or a linear material, and jets and supplies the powder material to the base. Or, an additional material supply device for supplying the linear material, a light irradiation device for irradiating a light beam to the powder material or the linear material supply portion of the base, and the powder supply of the additional material supply device or the And a controller that controls the supply of the linear material and the light irradiation of the light irradiation device, and controls the relative scanning of the light beam with respect to the base.

The light irradiation device includes a central light beam irradiation unit that irradiates a central light beam as the light beam to the center of the powder material supply unit or the linear material supply unit, and an outside of the central light beam as the light beam. An outer light beam irradiation unit for irradiating a light beam is provided, and the control device controls the output condition of the central light beam irradiation unit and the output condition of the outer light beam irradiation unit independently, so that the central light beam is emitted. The shape is added by increasing the peak in the beam density profile of the beam from the peak in the beam profile of the power density of the outer light beam.

Thus, the preheat treatment can be performed with the outer light beam as a pretreatment for the additional treatment of the modeled object, so that it is not necessary to greatly increase the peak in the laser beam profile of the power density of the central light beam. As a result, rapid heating by the central light beam can be reduced and spatter can be suppressed. In addition, since the heat retaining process can be performed as a post-treatment of the additional process of the shaped object with the outer light beam, rapid solidification of the shaped object can be suppressed and cracking can be prevented. Therefore, a high-quality molded object can be added to the base.

(2. Second mode of additional manufacturing apparatus)
An additional manufacturing apparatus according to a second aspect of the present invention is an additional manufacturing apparatus for adding a modeled product to a base using a plurality of types of powder materials, and a component ratio for adjusting a component ratio of the plurality of types of powder materials. With respect to the additional material supply device that has an adjusting device and supplies the powder material with the component ratio adjusted to the base by jetting it, and the powder material supply unit with the component ratio adjusted in the base. A light irradiation device that irradiates a light beam, and a control device that controls the powder supply of the additional material supply device and the light irradiation of the light irradiation device, and controls the relative scanning of the light beam with respect to the base. Prepare

The light irradiation device includes a central light beam irradiation unit that irradiates a central light beam as the light beam at the center of the powder material supply unit whose component ratio has been adjusted, and outside light as the light beam outside the central light beam. An outer light beam irradiating unit for irradiating a beam, and the control device adds an intermediate shaped object whose component ratio gradually changes in the thickness direction to the surface of the base to form the intermediate shaped object. The output condition of the central light beam irradiation unit and the output condition of the outer light beam irradiation unit are independently controlled according to the change in the component ratio.

With such a configuration, the difference in the coefficient of thermal expansion between the peripheral surface of the base and the intermediate shaped article can be formed to gradually decrease as it approaches the boundary between the peripheral surface of the base and the intermediate shaped article. Further, the difference in coefficient of thermal expansion between the intermediate shaped article and the shaped article can be formed so as to gradually decrease as it approaches the boundary between the intermediate shaped article FC and the shaped article FF. Accordingly, by adding the intermediate shaped article FC to the base B and the shaped article FF to the intermediate shaped article FC, it is possible to significantly suppress the occurrence of cracks due to the difference in thermal expansion coefficient.

It is a schematic diagram of the additional manufacturing device which concerns on 1st, 2nd embodiment of this invention. It is a perspective view which shows the base which adds a modeling thing with the addition manufacturing apparatus of FIG. It is the figure which looked at the base of Drawing 2A which added a model thing from the direction of a central axis. It is a figure which shows the relationship between the power density and the laser beam irradiation range in the 1st step (initial preheat treatment of the peripheral surface of a base) when adding a molded article to a base with the additional manufacturing apparatus of FIG. It is a figure which shows the relationship between the power density and the laser beam irradiation range in the 2nd step (addition process of a modeling object) at the time of adding a modeling object to a base with the additional manufacturing apparatus of FIG. It is sectional drawing which shows the initial state of the molded article added to the base when adding a molded article with the additional manufacturing apparatus which concerns on 1st embodiment. FIG. 4B is a cross-sectional view showing an intermediate state and an added state of the shaped article added to the base when the scanning progresses from the state of FIG. 4A. It is a flow chart for explaining operation of the additional manufacturing device concerning a first embodiment. It is a 1st figure explaining each scanning state of the light beam in operation|movement of the additional manufacturing apparatus which concerns on 2nd embodiment. It is a 2nd figure explaining each scanning state of the light beam in operation|movement of the additional manufacturing apparatus which concerns on 2nd embodiment. It is a 3rd figure explaining each scanning state of the light beam in operation|movement of the additional manufacturing apparatus which concerns on 2nd embodiment. It is a graph which shows the temperature change of J section on the peripheral surface of a base in the state of FIG. 6A-FIG. 6C. It is a schematic diagram of an additional manufacturing device concerning a third embodiment of the present invention. It is a figure corresponding to FIG. 2B, and is the figure which looked at the base to which the modeled object was added by the additional manufacturing apparatus of 3rd embodiment from the central axis line direction. FIG. 9 is a diagram showing the relationship between the power density and the laser light irradiation range in the first stage (initial preheat treatment of the peripheral surface of the base) when adding a shaped article to the base with the additional manufacturing apparatus of FIG. 8. It is a figure which shows the relationship between the power density and the laser beam irradiation range in the 2nd step (addition process of an intermediate|middle shaped object) at the time of adding a shaped object to a base with the additional manufacturing apparatus of FIG. FIG. 9 is a diagram showing a relationship between a power density and a laser light irradiation range in a third stage (model addition processing) when a model is added to the base by the additive manufacturing apparatus in FIG. 8. It is sectional drawing which shows the initial state of the molded article added to the intermediate molded article FC at the time of adding a molded article with the additional manufacturing apparatus which concerns on 3rd embodiment. FIG. 11B is a cross-sectional view showing an intermediate state and an added state of a model added to the intermediate model FC when the scanning progresses from the state of FIG. 11A. It is a flow chart for explaining operation of an additional manufacturing device concerning a third embodiment. It is a schematic diagram showing another example of the light irradiation device of an additional manufacturing device.

<1. First embodiment>
(1-1. Outline of additional manufacturing device)
The outline of the additional manufacturing apparatus according to the first embodiment of the present invention will be described. The additive manufacturing apparatus according to the first embodiment adds a modeled object to a base using one type of powder material by the LMD method. The powder material and the base may be different types of materials or the same type of materials.

In this example, a case where a shaped article made of a powder material of tungsten carbide (WC) (hereinafter, referred to as a first powder material) is added to a base B made of carbon steel (S45C) will be described. In addition to the first powder material, a powder material such as nickel (Ni) and cobalt (Co) that plays a role of a binder for the first powder material (hereinafter referred to as a binding powder material) is also used in the additional manufacturing. ..

As shown in FIG. 1, the additional manufacturing apparatus 100 includes an additional material supply device 110, a light irradiation device 120, a control device 130, and the like. Here, as shown in FIG. 2A, the additional manufacturing apparatus 100 includes a cylindrical member B2 in a base B having a shape in which small-diameter cylindrical members B2 and B2 are coaxially integrated on both side surfaces of a large-diameter disk member B1. , B2 on the open end side of the peripheral surface (supporting portions of bearings (not shown)) B2S, B2S indicated by mesh lines, the case where the modeled object FF is added will be described.

At the time of this additional manufacturing, as shown in FIG. 1, the additional manufacturing apparatus 100 rotates the base B around the central axis C by the motor M1 and moves it in the central axis C direction by the motor M2. As a result, a modeled object can be added to the entire peripheral surfaces B2S, B2S on the open end side of the cylindrical members B2, B2. Although details will be described later, the modeled object has a one-layer structure of the modeled object FF (see FIG. 2B).

The additional material supply device 110 shown in FIG. 1 includes a first hopper 111, a gas cylinder 114, and an injection nozzle 115. The first hopper 111 stores the first powder material P1 in which the combined powder material is mixed. In this example, the modeled object FF is composed of a large amount of the first powder material P1 and a small amount of the combined powder material, and therefore the amount of the combined powder material mixed with the first powder material P1 is the amount of the combined powder material in the modeled object FF. The amount corresponds to.

The powder introduction valve 113a is connected to the first hopper 111 by a pipe 111a. The powder supply valve 113c is connected to the injection nozzle 115 by a pipe 115a. The gas introduction valve 113d is connected to the gas cylinder 114 by a pipe 114a.

The injection nozzle 115 injects the first powder material P1 onto the peripheral surface B2S of the cylindrical member B2 of the base B by using high-pressure nitrogen supplied from the gas cylinder 114, for example. In this example, the two injection nozzles 115 are arranged 180 degrees apart, but one injection nozzle or three or more injection nozzles arranged at equal angular intervals may be provided. The gas for supplying the first powder material P1 is not limited to nitrogen, but may be an inert gas such as argon.

The light irradiation device 120 includes a central light beam irradiation unit 121, a central light beam light source 122, an outer light beam irradiation unit 123, and an outer light beam light source 124. The light irradiation device 120 irradiates the central surface light beam LC from the central light beam light source 122 to the peripheral surface B2S (supplying portion of the first powder material P1) of the cylindrical member B2 of the base B through the central light beam irradiation portion 121. At the same time, the outer light beam LS is irradiated from the outer light beam light source 124 through the outer light beam irradiation unit 123.

In this example, the central light beam irradiation unit 121 irradiates the central light beam LC having a circular irradiation shape (central light irradiation range CS). Further, the outer light beam irradiation unit 123 irradiates the outer light beam LS having a ring-shaped irradiation shape (outer light irradiation range SS) surrounding the outer periphery of the central light beam LC. The central light beam LC plays a role of adding the modeled object FF on the peripheral surface B2S of the cylindrical member B2 of the base B. The role of the outer light beam LS will be described later. Although laser light is used as the central light beam LC and the outer light beam LS, it is not limited to laser light and may be an electron beam as long as it is an electromagnetic wave.

The control device 130 controls the powder supply of the additional material supply device 110 and the light irradiation of the light irradiation device 120, and the relative of the central light beam LC and the outer light beam LS to the peripheral surface B2S of the cylindrical member B2 of the base B. Control scanning. That is, the controller 130 controls the opening and closing of the powder supply valve 113c and the gas introduction valve 113d to control the injection and supply of the first powder material P1 from the injection nozzle 115.

Further, the control device 130 controls the operations of the central light beam light source 122 and the outer light beam light source 124 to output the respective central light beam LC and outer light beam LS, that is, the central light beam LC and outer light beam LS. And the distribution shape (laser beam profile) of the laser output (power density) per unit area of the central light irradiation range CS and the outer light irradiation range SS are independently controlled.

Further, the control device 130 controls the rotation of the motor M1 to rotate the base B around the central axis C, and controls the rotation of the motor M2 to move the base B in the central axis C direction. The relative scanning of the central light beam LC and the outer light beam LS with respect to the peripheral surface B2S of the cylindrical member B2 of the base B is controlled.

(1-2. Method of adding shaped article)
Next, a method of adding a modeled object will be described. Here, as described in the problem to be solved by the invention, in the LMD method, when a hard shaped object is added to the base, spatter may occur during rapid heating, and cracks may occur during rapid solidification. However, there is a problem that the accuracy of the modeled object is reduced.

The present inventor has found that the generation of spatters and cracks can be suppressed by independently controlling the laser output of each of the central light beam LC and the outer light beam LS and the laser beam profile of each power density. Specifically, as shown in FIG. 2B, the modeled object FF is added to the peripheral surface B2S of the cylindrical member B2 of the base B.

In the method of adding the modeled object FF, as a first step, an initial preheat treatment is performed by the outside light beam LS as a pretreatment in the process of adding the modeled object FF. At this time, the addition process of the modeled object FF according to the present invention is a process in the second stage. When the temperature of the peripheral surface B2S of the base B is low, thermal energy due to laser irradiation easily escapes to the base B, which easily causes a melting defect in the additional process of the model FF performed in the second stage. The peripheral surface B2S of the base B is preheated at a stage. At this time, the laser outputs of the central light beam LC and the outer light beam LS in the initial preheat treatment are controlled so that the peripheral surface B2S of the base B does not melt and reaches a predetermined temperature.

That is, in the first stage, the control device 130 does not supply the first powder material P1, and the central light irradiation range CS of the central light beam LC and the outer light irradiation of the outer light beam LS from the temperature measuring device (not shown). While monitoring the measurement temperature in the range SS, as shown in the power density graph of FIG. 3A, the peak LCP1 in the laser beam profile of the power density of the central light beam LC is changed to the laser beam profile of the power density of the outer light beam LS. Control is performed to reduce the peak LSP1.

The reason for reducing the power density peak LCP1 of the central light beam LC from the power density peak LSP1 of the outer light beam LS is that the central light beam LC is surrounded by the outer light beam LS, and therefore the heat generated by the central light beam LC is This is because it is easy to get trapped and the heat generated by the outer light beam LS easily escapes to the outside. In this way, since the power density of the central light beam LC is low, it is possible to suppress the generation of spatter due to the excessive heat input of the central light beam LC. Further, since a large amount of energy can be input as the entire laser output while suppressing the peak LCP1, it is possible to efficiently preheat while suppressing the generation of spatter.

Next, as a second step, as shown in FIG. 4A, by irradiating the central light beam LC, the peripheral surface B2S of the base B and the first powder material P1 are melted and melted in the central light irradiation range CS. A melting process (corresponding to the first melting process) for forming a pond MP (corresponding to the first melting pool) is performed. At the same time, the outer light beam LS is melted by the first light beam Be1 which is a part of the outer light beam LS in the front irradiation range SSF in the scanning direction SD (see FIG. 4A) of the outer light irradiation range SS. A preheat treatment (corresponding to the first preheat treatment) is performed as a pretreatment of the pond MP forming treatment (corresponding to the first pretreatment).

Then, as shown in FIG. 4B, the central light beam LC is scanned in the scanning direction SD (scanning direction SD) (in this example, the pedestal B rotates and scans. The molten pool MP is expanded by adding the shape of the first powder material P1 to the base B.

Then, at this time, at the same time, the first light beam Be1 (outer light beam LS) in the irradiation range SSF on the front side in the scanning direction SD of the outer light irradiation range SS of the outer light beam LS is used as a pre-process for forming the molten pool MP. And the second light beam Be2 which is a part of the outer light beam LS in the rear irradiation range SSB of the outer light beam LS in the scanning direction SD of the outer light beam LS is added to the modeling object FF. A heat retention process (corresponding to the first heat retention process) is performed as a post-process of the process.

At this time, the control device 130 controls to increase the peak LCP3 in the laser beam profile of the power density of the central light beam LC from the peak LSP3 in the laser beam profile of the power density of the outer light beam LS, as shown in FIG. 3B. To do. The laser output of the central light beam LC is controlled to a temperature at which the first powder material P1 can be melted to form the molten pool MP. The laser output of the outer light beam LS (first light beam Be1, second light beam Be2) is controlled so that the first powder material P1 and the modeled object FF do not melt and reach a predetermined temperature.

As described above, in the irradiation range SSF on the front side in the scanning direction SD of the outside light irradiation range SS of the outside light beam LS, the first light beam Be1 (outside light beam LS) is used as a pre-process for forming the molten pool MP. By performing the preheat treatment, the peripheral surface B2S of the base B becomes a high temperature state. Therefore, it is not necessary to greatly increase the peak LCP3 in the laser beam profile of the power density of the central light beam LC.

Thereby, the rapid heating of the peripheral surface B2S by the central light beam LC can be reduced, and the generation of spatter can be suppressed. Further, in the irradiation range SSB on the rear side in the scanning direction SD of the outside light irradiation range SS of the outside light beam LS, the second light beam Be2 performs the heat retention process as the post-treatment of the formation process of the molten pool MP, so that the modeling is performed. The rapid solidification of the product FF can be suppressed, and the occurrence of cracks can be prevented.

(1-3. Operation of additional manufacturing device)
Next, the operation of adding the modeled object FF to the peripheral surface B2S of the one cylindrical member B2 of the base B by the additional manufacturing apparatus 100 will be described with reference to the flowchart of FIG. It is assumed that the first hopper 111 stores the first powder material P1 mixed with the combined powder material.

Further, it is assumed that one end of the peripheral surface B2S of the one cylindrical member B2 of the base B is positioned at a predetermined addition position in the addition manufacturing apparatus 100. In addition, the control device 130 includes the first powder material such as the respective laser outputs of the central light beam LC and the outer light beam LS and the respective peaks LCP3 and LSP3 of the laser beam profile of each power density in the above-mentioned first and second stages. Data such as the supply amount of P1, the rotation speed and the moving speed of the base B, and the like are stored in advance.

First, the control device 130 starts the rotation and movement of the base B to simultaneously turn on the light irradiation device 120 in order to execute the above-described first step (initial preheat treatment for the peripheral surface B2S of the base B). (Step S1 in FIG. 5). Specifically, the control device 130 drives the motors M1 and M2 to rotate the base B about the central axis C and move it in the central axis C direction (the other end direction of the peripheral surface B2S).

At the same time, the control device 130 turns on the central light beam light source 122 to irradiate the central light beam LC from the central light beam irradiation unit 121 to the peripheral surface B2S of the base B, and also turns on the outer light beam light source 124 to turn the outer light beam source 124 on. The peripheral surface B2S of the base B is irradiated with the outer light beam LS from the light beam irradiation unit 123, and the initial preheat treatment is performed on the peripheral surface B2S of the base B.

Then, the control device 130 determines whether or not the initial preheat treatment for the peripheral surface B2S of the base B is completed (step S2 in FIG. 5), and when the initial preheat treatment is completed, the light irradiation device 120 is turned on. It is turned off and the base B is returned to the start position of the first stage, and the rotation and movement of the base B are stopped (step S3 in FIG. 5).

Next, the control device 130 turns on the additional material supply device 110 to start the rotation and movement of the base B in order to execute the above-described second step (addition processing of the modeled object FF), and at the same time, the light irradiation device. 120 is turned on (step S4 in FIG. 5). Specifically, the control device 130 opens the gas introduction valve 113d and the powder supply valve 113c, and injects the first powder material P1 from the injection nozzle 115 to the peripheral surface B2S of the base B with the high-pressure nitrogen from the gas cylinder 114. And supply. Further, the control device 130 turns on the central light beam light source 122 to irradiate the central light beam LC from the central light beam irradiating section 121 to the peripheral surface B2S of the base B, and also turns on the outer light beam light source 124 to the outside. The outer light beam LS is irradiated from the light beam irradiation unit 123 onto the peripheral surface B2S of the base B.

Then, the control device 130 drives the motors M1 and M2 to rotate the base B around the central axis C and move it in the central axis C direction (the other end direction of the peripheral surface B2S). At this time, as described above, the outer light beam LS (first light beam Be1) irradiated to the front irradiation range SSF of the outer light beam LS in the scanning direction SD serves as a pretreatment for the formation processing of the molten pool MP. A preheat treatment is performed. At the same time, the outside light beam LS (second light beam Be2) emitted to the irradiation area SSB on the rear side of the outside light beam LS in the scanning direction SD performs heat retention as a post-treatment for the addition of the modeled object FF. Be done.

As a result, in the central light irradiation range CS where the first light beam Be1 (central light beam LC) is irradiated, the molten pool MP is sequentially improved in accordance with the scanning in the scanning direction SD in the state where the preheat treatment is performed. Can be formed into Further, in the outer light irradiation range SS where the second light beam Be2 (outer light beam LS) is irradiated, the formed molten pool MP is sequentially kept in good temperature in accordance with the scanning in the scanning direction SD. As a result, the modeled object FF having no spatter and no crack is formed.

Then, the control device 130 determines whether or not the adding process of the modeling object FF added to the peripheral surface B2S of the base B is completed (step S5 in FIG. 5). Then, when the addition process of the modeled object FF is completed, the additional material supply device 110 and the light irradiation device 120 are turned off, the rotation and movement of the base B are stopped (step S6 in FIG. 5), and all the processes are completed. To do.

(1-4. Effects of the first embodiment)
According to the first embodiment, the additive manufacturing apparatus 100 is an apparatus that adds a modeled object to the base B using a powder material. The additional manufacturing apparatus 100 includes an additional material supply device 110 for injecting and supplying the first powder material P1 to the base B, and a light beam for the supply portion (peripheral surface B2S) of the first powder material P1 on the base B. The light irradiating device 120 for irradiating the light, the supply of the first powder material P1 of the additional material supplying device 110, and the light irradiation of the light irradiating device 120 are controlled, and the relative scanning of the light beam with respect to the base B is controlled. And a control device 130.

The light irradiation device 120 irradiates the central light beam irradiation unit 121 that irradiates the central light beam LC to the center of the supply unit (peripheral surface B2S) of the first powder material P1 and the outer light beam LS to the outside of the central light beam LC. The outer light beam irradiating section 123 is provided. Then, the control device 130 independently controls the output condition of the central light beam irradiation unit 121 and the output condition of the outer light beam irradiation unit 123 so that the peak LCP3 in the beam profile of the power density of the central light beam LC is outside. The modeled object FF is added by increasing it from the peak LSP3 in the beam profile of the power density of the light beam LS.

In this way, since the first light beam Be1 (outer light beam LS) can perform the pre-heat treatment (first pre-heat treatment) as the pre-treatment for the additional treatment of the modeled object FF, the power density of the central light beam LC is increased. It is not necessary to increase the peak LCP3 in the laser beam profile of. Thereby, the rapid heating of the peripheral surface B2S of the base B due to the irradiation of the central light beam LC can be reduced, and the generation of spatter can be suppressed. In addition, since the second light beam Be2 (outer light beam LS) can perform the heat retention process as the post-treatment of the additional process of the model FF, rapid solidification of the model FF can be suppressed and the occurrence of cracks can be prevented. .. Therefore, the high-quality molded object FF can be added to the base B.

Further, according to the first embodiment, the control device 130 scans the central light beam LC and the outer light beam LS in the same scanning direction SD, and the central light beam LC causes the central light irradiation range CS of the base B to be scanned. Of the molten pool MP (first molten pool) (first forming process) and the melting process of the first powder material P1 (first melting process). Further, the control device 130 performs a pre-heat treatment (first pre-heat treatment) as a pre-treatment for the formation process of the molten pool MP with the first light beam Be1 on the front side in the scanning direction SD of the outer light beam LS, so that the outer light beam LS is affected. With the second light beam Be2 on the rear side in the scanning direction SD, a heat retention process (first heat retention process) is performed as a post-process for the formation process of the molten pool MP.

In this way, since the preheat treatment for forming the molten pool MP can be simultaneously performed by scanning the light beam in the scanning direction SD once, rapid heating can be efficiently reduced, and generation of spatter can be suppressed. At this time, at the same time, in the irradiation range SSB on the rear side in the scanning direction SD of the outside light irradiation range SS of the outside light beam LS, a heat retention process is performed as a post-process for forming the molten pool MP. Also in this case, since the heat treatment of the molten pool MP can be performed by scanning the light beam once, it is possible to efficiently suppress the rapid solidification of the modeled object FF and prevent the occurrence of cracks.

<2. Second embodiment>
(2-1. Overview of additional manufacturing apparatus 200)
Next, an outline of the additional manufacturing apparatus 200 (see FIG. 1) according to the second embodiment will be described. The additional manufacturing apparatus 200 according to the second embodiment is different from the additional manufacturing apparatus 100 according to the first embodiment in the method of preheat treatment and heat retention processing performed on the peripheral surface B2S of the base B, and the other portions are different. Is the same. Therefore, only different parts will be described in detail, and description of similar parts will be omitted. Also, the same components will be described with the same reference numerals.

As shown in FIG. 1, the additional manufacturing apparatus 200 of the second embodiment includes an additional material supply device 110, a light irradiation device 120, a control device 230, and the like. Similar to the first embodiment, the additional manufacturing apparatus 200 includes a cylindrical member B in a shape in which cylindrical members B2 and B2 having a small diameter are coaxially integrated with both side surfaces of a disk member B1 having a large diameter shown in FIG. 2A. A molded article is added to the peripheral surfaces (supporting portions of bearings (not shown)) B2S and B2S indicated by the mesh lines on the open end side of B2 and B2.

The control device 230 controls the powder supply of the additional material supply device 110 and the light irradiation of the light irradiation device 120, and makes the center light beam LC and the outer light beam LS relative to the peripheral surface B2S of the cylindrical member B2 of the base B. Control scanning. Details will be described later. In the present embodiment as well, similar to the first embodiment, the initial preheat treatment in the first stage is also performed, but the detailed description will be omitted.

(2-2. Method of adding shaped article)
Next, a method of adding a modeled object will be described. Specifically, as in the first embodiment, as shown in FIG. 2B, a model FF having a one-layer structure is added to the peripheral surface B2S of the cylindrical member B2 of the base B. In the method of adding the modeled object FF according to the present embodiment, in the second step, the control device 230 causes the central light beam LC and the outer light beam LS to move in the same direction by a predetermined distance L1 in the circumferential direction of the circumferential surface B2S. The model FF is added by scanning a plurality of times. At this time, one scan is a scan on the peripheral surface B2S around the central axis C of the cylindrical member B2, and a plurality of scans means a plurality of scans while moving in the central axis C direction of the cylindrical member B2. It means to do it once.

The details will be described below. In the explanation, each scan SC1-SC3 will be defined. As shown in FIGS. 6A to 6C in which the circumferential surface B2S is developed in the circumferential direction, the scanning located at the center in the central axis C direction in the scanning set Q1 for one light beam is defined as the second scanning SC2. The second scan SC2 is a scan with the central light beam LC. Further, the scanning by the outer light beam LS (corresponding to the third light beam Be3) on one side (the right side in FIG. 6A) of the left and right sides in the scanning direction of the central light beam LC is defined as the first scan SC1. Further, the scanning by the outer light beam (corresponding to the fourth light beam Be4) on the other side (the left side in FIG. 6A) of the left and right sides in the scanning direction of the central light beam LC is defined as the third scan SC3.

The second scan SC2 of the central light beam LC is a formation process (corresponding to the second formation process) of the molten pool MP (corresponding to the second molten pool) in the central light irradiation range CS of the base B, and the first powder material. The P1 melting process (corresponding to the second melting process) is performed. Further, the first scanning SC1 by the third light beam Be3 (the outer light beam LS on the one side) performs a preheat treatment (corresponding to a second preheat treatment) as a pretreatment for the forming treatment for forming the molten pool MP (corresponding to the second preheat treatment). Part J of FIG. 6A). Further, the third scanning SC3 by the fourth light beam Be4 (the outer light beam LS on the other side) performs a heat retention process (corresponding to the second heat retention process) as a post-process for the formation process of the molten pool MP (FIG. 6A). Part K).

That is, the central light beam LC and the outer light beam LS (third light beam Be3, fourth light beam Be4) are simultaneously scanned in the same direction by a predetermined distance L1, so that the second scan SC2 (second molten pool MP No. 2 second formation process), the first scan SC1 (second preheat treatment), and the third scan SC3 (second heat retention process) are simultaneously performed (see Q1 in FIGS. 6A, 6B, and 6C). At this time, when viewed with the second scanning SC2 performed by the central light beam LC as a reference, the second scanning SC2 of FIG. 6B to be scanned next time by the central light beam LC is the current scanning of the central light beam LC shown in FIG. 6A. The central light beam LC and the outer light beam LS (third light beam Be3, fourth light beam Be4) are so arranged as to be adjacent to the second scanning SC2 on one side (right side in FIGS. 6A and 6B) a plurality of times in the same direction. Then, a predetermined distance L1 is scanned.

Further, in the above, when adding the modeled object FF on the peripheral surface B2S, the control device 230 sets the peak LCP3 in the laser beam profile of the power density of the central light beam LC to the outer light beam LS, as shown in FIG. 3B. The control is performed so that the power density is increased from the peak LSP3 in the laser beam profile. At this time, the laser output of the central light beam LC is controlled to a temperature at which the peripheral surface B2S and the first powder material P1 are melted to form the molten pool MP, as described above. Further, the laser output of the outer light beam LS is controlled so that the first powder material P1 and the peripheral surface B2S of the base are not melted and reach a predetermined temperature.

Then, as described above, the scanning performed in the circumferential direction of the circumferential surface B2S by the predetermined distance L1 is repeated a plurality of times toward one side (the right side in FIG. 6A) in the central axis C direction of the circumferential surface B2S. A part of the modeled object FF is added to B2S. At this time, the scanning direction SD (scanning direction) of the present central light beam LC and outer light beam LS and the next scanning direction SD of the central light beam LC and outer light beam LS are the same as described above. That is, the position of the starting point R is always on the same side in each scan.

Here, the temperature change of the J portion in FIGS. 6A to 6C will be described. The temperature change of the J portion changes as shown in the graph of FIG. 7. FIG. 7 is a graph showing the temperature change at the starting point R of each of the scans SC1, SC2, SC3 in the J section when the horizontal axis represents time and the vertical axis represents temperature. In FIG. 6A, the J portion is a portion to be preheated. In FIG. 6B, the J portion is a portion where the molten pool MP is formed. Further, in FIG. 6C, the J portion is a portion where the molten pool MP is subjected to heat retention processing.

As can be seen from FIG. 7, in the preheat treatment, the start point R of the first scan SC1 by the third light beam Be3 (outer light beam LS) on the peripheral surface B2S is heated by the start of the first scan SC1 ( (See V1 in FIG. 7). At this time, the temperature at V1 is controlled so as not to exceed the melting point (freezing point) of the peripheral surface B2S of the base B. After that, the first scan SC1 of the third light beam Be3 is scanned by a predetermined distance L1 in the direction away from the starting point R, so that the temperature at the starting point R decreases (see arrow Ar1 in FIG. 7).

Then, in the J section, the second scanning SC2 by the central light beam LC is started from the scanning start point R. As a result, the temperature of the J portion again rises (see arrow Ar2 in FIG. 7), exceeds the freezing point (melting point), and the peripheral surface B2S is melted to form the molten pool MP (second molten pool). At this time, the J portion is heated by the central light beam LC on the basis of the state preheated by the first scanning SC1, so that the peripheral surface B2S can be stably melted without being rapidly heated and spatter of Occurrence is well suppressed.

After that, the second scan SC2 by the central light beam LC is moved by a predetermined distance L1 in the direction away from the starting point, so that the second scanning SC2 moves away from the starting point R, and the temperature at the starting point R decreases (see arrow Ar3 in FIG. 7). .. However, at this time, before the temperature of the molten metal forming the molten pool MP falls below the freezing point, the third scanning SC3 by the fourth light beam Be4 (outer light beam LS) which is the next scanning and performs heat retention processing is performed. It starts from the starting point R of the scanning in the J section. Therefore, the temperature decrease gradient of the molten metal that has begun to be rapidly cooled becomes gentle from the position of point W in FIG. 7 where the heat retention process is started, and thereafter, the molten metal is solidified by falling below the freezing point and It is formed. As described above, since the modeled object FF is formed by gentle cooling, not by rapid cooling, the occurrence of cracks is favorably suppressed.

That is, in the present embodiment, the third scanning SC3 by the fourth light beam Be4 (outer light beam LS) causes the starting point R of the scanning in the J portion before the temperature of the molten metal forming the molten pool MP becomes equal to or lower than the freezing point. A predetermined distance L1 for performing each of the scans SC1, SC2, SC3 is set so as to start from. Further, in the present embodiment, the predetermined distance L1 is a length equal to or less than the circumferential length around the central axis C on the circumferential surface B2S of the cylindrical member B2. At this time, it is preferable that the predetermined distance L1 is equal to or equal to the circumferential length of the circumferential surface B2S. As a result, on the peripheral surface B2S, scanning is performed once in the peripheral direction on the peripheral surface B2S, or an integral number of times after the addition of a part of the modeled object FF in the central axis C direction is completed. It is possible to add the modeled object FF which is free from spatter and has no cracks to the entire circumference of the circumferential surface B2S in the circumferential direction.

(2-3. Effects of Second Embodiment)
According to the second embodiment, the control device 230 scans the central light beam LC and the outer light beam LS in the same direction for a predetermined distance L1. That is, the formation process (second formation process) of the molten pool MP (second molten pool) in the central light irradiation range CS of the base B by the central light beam LC in the second scan SC2 and the melting process of the first powder material P1. (Second melting process) is performed. Further, a preheat treatment (second preheat treatment) as a pretreatment for the treatment for forming the molten pool MP is performed by the third light beam Be3 in the first scan SC1. Further, the fourth light beam Be4 in the third scan SC3 performs a heat retention process (second heat retention process) as a post-process for the formation process of the molten pool MP. Then, thereafter, the central light beam LC and the outer light beam LS are separated by a predetermined distance L1 in the same direction so that the second scanning SC2 performed next time by the central light beam LC is adjacent to the second scanning SC2 performed this time on one side. To scan.

Thereby, for example, the temperature change in the J portion of FIG. 6A becomes as shown in FIG. That is, the peripheral surface B2S of the pedestal B is formed by performing the preheat treatment as the pretreatment for the formation process of the molten pool MP in the irradiation range SSF on the one side of the scanning direction SD in the outside light irradiation range SS of the outside light beam LS. The temperature is high. Therefore, it is not necessary to greatly increase the peak LCP3 in the laser beam profile of the power density of the central light beam LC.

Therefore, the rapid heating by the central light beam LC can be reduced and the generation of spatter can be suppressed. Further, in the irradiation range SSB on the other side in the scanning direction SD in the outside light irradiation range SS of the outside light beam LS, a heat retention process as a post-process for the formation process of the molten pool MP is performed to rapidly solidify the modeled object FF. It can be suppressed and cracking can be prevented.

Further, according to the second embodiment, the scanning direction SD of the central light beam LC and the outer light beam LS scanned this time and the scanning direction SD of the central light beam LC and the outer light beam LS scanned next time are the same. As a result, heat retention can be started with the position of the lowest temperature of the molten metal in the molten pool MP as the starting point R, so that rapid solidification of the model FF can be suppressed and cracking can be prevented.

Further, according to the second embodiment, since the temperature of the molten pool MP can be reliably maintained at a predetermined temperature or higher, rapid solidification of the model FF can be suppressed, and cracking can be prevented. Further, according to the second embodiment, the predetermined temperature is the solidification temperature of the molten metal melted in the molten pool MP. Thereby, the predetermined distance L1 can also be easily set according to the solidification temperature of the molten metal melted in the molten pool MP.

In the additional manufacturing apparatus 200 of the second embodiment, the pre-heat treatment is performed by the first scanning SC1 by the third light beam Be3 (outer light beam LS on one side), and the heat retention process is performed by the fourth light beam Be4 (on the other side). The aspect of performing the third scanning SC3 by the outer light beam LS) has been described. However, actually, the outer light beam LS is formed in a ring shape. Therefore, the first light beam Be1 (front side) and the second light beam Be2 (rear side) in the first embodiment also contribute to the preheat treatment and the heat retention treatment. In this case, since the scanning of the central light beam LC and the outer light beam LS may be controlled with lower energy, the efficiency is high.

However, the present invention is not limited to this aspect, and when it is desired to eliminate the influence of the first light beam Be1 (front side) and the second light beam Be2 (rear side), the outer light beam LS is not ring-shaped, and the third light beam LS is not. The light irradiation device may be configured so that the beam Be3 and the fourth light beam Be4 can be individually irradiated. This also provides a sufficient effect.

<3. Third embodiment>
(3-1. Outline of additional manufacturing apparatus 300)
Next, an outline of the additional manufacturing apparatus 300 according to the third embodiment of the present invention will be described. In addition, as will be described later in detail, the role of the powder material of carbon steel (S45C) (hereinafter referred to as the second powder material) and the binder of the first powder material in addition to the first powder material P1 at the time of this additional manufacturing. A powder material such as nickel (Ni) or cobalt (Co) that plays a role in the above (hereinafter referred to as a binding powder material) is also used.

In the additive manufacturing apparatus 300, the modeled object added by the additive manufacturing apparatus 300 to the additive manufacturing apparatuses 100 and 200 of the first and second embodiments has a two-layer structure of an intermediate modeled object FC and a modeled object FF. (See Figure 9). The additional manufacturing apparatus 300 adds a modeled object to the base B using one or more kinds of powder materials by the LMD method. At this time, the powder material and the base B may be different types of materials or the same type of materials. It should be noted that in the following, mainly, portions different from the first embodiment will be described in detail, and description of similar portions will be omitted. Further, in the case of the same configuration, the same reference numeral may be attached and described in the drawings.

In this example, similar to the first embodiment, a case where a shaped article made of a powdered material of tungsten carbide (WC) (hereinafter referred to as a first powdered material) is added to a base B made of carbon steel (S45C) will be described. To do. As shown in FIG. 8, the additional manufacturing apparatus 300 includes an additional material supply device 310, a light irradiation device 120, a control device 330, and the like.

In the additional manufacturing, the additional manufacturing apparatus 300 rotates the base B around the central axis C by the motor M1 and moves the base B in the central axis C direction by the motor M2. As a result, a modeled object can be added to the entire peripheral surfaces B2S, B2S on the open end side of the cylindrical members B2, B2. Although details will be described later, the modeled article has a two-layer structure of an intermediate modeled article FC and a modeled article FF (see FIG. 9 ).

The additional material supply device 310 includes a first hopper 111, a second hopper 112, a component ratio adjusting device 113, a gas cylinder 114, and an injection nozzle 115. The first hopper 111 and the second hopper 112 store the first powder material P1 mixed with the combined powder material and the second powder material P2 mixed with the combined powder material, respectively. In this example, the modeled object FF is composed of a large amount of the first powder material P1 and a small amount of the combined powder material, and therefore the amount of the combined powder material mixed with the first powder material P1 is the amount of the combined powder material in the modeled object FF. The amount corresponds to.

Further, since the intermediate molded article FC is made of a material in which the amounts of the binding powder material and the second powder material P2 decrease and the amount of the first powder material P1 increases as the thickness increases, the intermediate powder product FC becomes the second powder material P2. The amount of the combined powder material to be mixed is an amount corresponding to the amount of the first powder material P1 in the intermediate shaped product FC. It should be noted that the configuration may be such that a hopper capable of storing only one type or three or more types of powder materials is provided.

The component ratio adjusting device 113 adjusts the component ratio of the first powder material P1 mixed with the combined powder material from the first hopper 111 and the second powder material P2 mixed with the combined powder material from the second hopper 112. .. The component ratio adjusting device 113 includes a powder agitator 113e to which the powder introduction valves 113a and 113b, the powder supply valve 113c, and the gas introduction valve 113d are connected.

The powder introduction valves 113a and 113b are connected to the first hopper 111 and the second hopper 112 by pipes 111a and 112a, respectively, the powder supply valve 113c is connected to the injection nozzle 115 and pipe 115a, and the gas introduction valve 113d is The pipe 114a is connected to the gas cylinder 114.

The injection nozzle 115 uses, for example, a powder material (hereinafter, referred to as a third powder material) P3, whose component ratio is adjusted, sent from the component ratio adjusting device 113 by high-pressure nitrogen supplied from the gas cylinder 114, as a base. It is jetted and supplied to the peripheral surface B2S of the cylindrical member B2 of B. The light irradiation device 120 has the same configuration as the light irradiation device 120 of the first embodiment, and thus the description thereof will be omitted.

The control device 330 controls the powder supply of the additional material supply device 310 and the light irradiation of the light irradiation device 120, and the relative of the central light beam LC and the outer light beam LS to the peripheral surface B2S of the cylindrical member B2 of the base B. Control scanning. That is, the control device 330 controls the rotation of the powder introduction valves 113a and 113b to adjust the component ratio of the first powder material P1 in which the binding powder material is mixed and the second powder material P2 in which the binding powder material is mixed. Then, the opening and closing of the powder supply valve 113c and the gas introduction valve 113d are controlled to control the injection and supply of the third powder material P3 from the injection nozzle 115.

In addition, the control device 330 controls the operations of the central light beam light source 122 and the outer light beam light source 124, respectively, to output conditions of the central light beam LC and the outer light beam LS, that is, the central light beam LC and the outer light beam LS. And the distribution shape (laser beam profile) of the laser output (power density) per unit area of the central light irradiation range CS and the outer light irradiation range SS are independently controlled.

Further, the control device 330 controls the rotation of the motor M1 to rotate the base B around the central axis C, and controls the rotation of the motor M2 to move the base B in the direction of the central axis C. The relative scanning of the central light beam LC and the outer light beam LS with respect to the peripheral surface B2S of the cylindrical member B2 of the table B is controlled.

(3-2. Method of adding shaped article)
Next, a method of adding a modeled object will be described. As shown in FIG. 9, on the peripheral surface B2S of the cylindrical member B2 of the base B, a three-layered structure, that is, an intermediate molded product FC is added to the surface of the cylindrical member B2 of the base B to form an intermediate molding. The object FF is added to the surface of the object FC. The intermediate shaped object FC is added such that the component ratios of the first powder material P1 in which the binding powder material is mixed and the second powder material P2 in which the binding powder material is mixed are different in stages (gradual change).

Specifically, in the intermediate molded article FC, the second powder material P2 mixed with the bonding powder material is 100% at the portion farthest from the portion closest to the peripheral surface B2S of the base B in the thickness direction (radial direction). From 0% to 0% linearly (stepwise), and the first powder material P1 mixed with the binding powder material increases linearly (stepwise) from 0% to 100%, which is a so-called graded layer. .. The modeled object FF is a layer in which the first powder material P1 mixed with the combined powder material is 100% and the second powder material P2 mixed with the combined powder material is 0%.

A portion of the intermediate shaped article FC near the peripheral surface B2S of the base B contains a large amount of the second powder material P2 (carbon steel (S45C)). Therefore, the difference in the coefficient of thermal expansion between the peripheral surface B2S (carbon steel (S45C)) of the base B and the intermediate shaped object FC gradually becomes closer to the boundary between the peripheral surface B2S of the base B and the intermediate shaped object FC. Will be reduced to. On the other hand, the portion of the intermediate shaped article FC near the shaped article FF contains a large amount of the first powder material (tungsten carbide (WC)). Therefore, the difference in coefficient of thermal expansion between the intermediate shaped article FC and the shaped article FF (tungsten carbide (WC)) gradually decreases as it approaches the boundary between the intermediate shaped article FC and the shaped article FF.

Therefore, by adding the intermediate model FC to the base B and the model FF to the intermediate model FC, it is possible to significantly suppress the occurrence of cracks due to the difference in thermal expansion coefficient. As a first step, the method for adding the intermediate shaped object FC and the shaped object FF is to perform an initial preheat treatment as a pretreatment for the addition processing of the intermediate shaped object FC performed in the second step by the central light beam LC and the outer light beam LS. To do. When the temperature of the peripheral surface B2S of the base B is low, thermal energy due to laser irradiation easily escapes to the base B, which is likely to cause a failure in the melting performed in the second stage. Preheat B2S. The laser outputs of the central light beam LC and the outer light beam LS at this time are controlled so that the peripheral surface B2S of the base B does not melt and reaches a predetermined temperature.

That is, the control device 330 does not supply the third powder material P3 in the first stage, and the central light irradiation range CS of the central light beam LC and the outer light irradiation range of the outer light beam LS from the temperature measuring device (not shown). Control for monitoring the measured temperature of SS and reducing the peak LCP4 in the laser beam profile of the power density of the central light beam LC from the peak LSP4 in the laser beam profile of the power density of the outer light beam LS, as shown in FIG. 10A. I do.

The reason for reducing the power density peak LCP4 of the central light beam LC from the power density peak LSP4 of the outer light beam LS is the same as the reason described in the first embodiment. Further, since the power density of the central light beam LC is low, it is possible to suppress the generation of spatter due to excessive heat input of the central light beam LC. Further, since a large amount of energy can be input as the entire laser output while suppressing the peak LCP1, it is possible to efficiently preheat while suppressing the generation of spatter.

Next, as a second step, the first powder material P1 is not melted, but the second powder material P2 is melted and the intermediate shaped article FC is added. That is, the control device 330 supplies the third powder material P3 whose component ratio is adjusted as described above, and outside the central light irradiation range CS and the outer light beam LS of the central light beam LC from the temperature measuring device (not shown). The measurement temperature of the light irradiation range SS is monitored. Then, by this monitoring, control is performed to reduce the peak LCP5 in the laser beam profile of the power density of the central light beam LC from the peak LSP5 in the laser beam profile of the power density of the outer light beam LS, as shown in FIG. 10B.

The peaks LCP5 and LSP5 of the central light beam LC and the outer light beam LS in the second stage need to melt the second powder material P2, and therefore the peaks LCP4 and LCP4 of the central light beam LC and the outer light beam LS in the first stage. The value is higher than that of LSP4. Furthermore, since the component ratio of the intermediate shaped object FC changes as the thickness increases, the control device 330 controls the central light irradiation range CS of the central light beam LC by the temperature measuring device (not shown) and the outside light of the outside light beam LS. Feedback control for varying the laser output of the central light beam LC and the outer light beam LS is performed while monitoring the measured temperature of the irradiation range SS. The relationship between the temperature and the laser output due to the difference in the component ratio is constructed in advance as a database.

In the second stage, for the same reason as in the first stage, the power density peak LCP5 of the central light beam LC is made smaller than the power density peak LSP5 of the outer light beam LS. Further, since the power density of the central light beam LC is low, it is possible to suppress the generation of spatter due to excessive heat input of the central light beam LC. Further, since a large amount of energy can be input as the entire laser output while suppressing the peak LCP5, it is possible to add the intermediate shaped object FC at high speed while suppressing the generation of spatter.

Next, as a third step, by irradiation with the central light beam LC, in the central light irradiation range CS of the intermediate shaped object FC, the intermediate shaped object FC and the third powder material P3 (actually, the first powder in which the combined powder material is mixed). A melting process is performed to melt (material only) to form a molten pool MP (see FIG. 11A). At the same time, a preheat treatment as a pretreatment for the formation process of the molten pool MP is performed in the irradiation range SSF on the front side in the scanning direction SD (see FIG. 11A) in the outer light irradiation range SS of the outer light beam LS with respect to the central light irradiation range CS. To do.

Then, as shown in FIG. 11B, the molten pool MP is enlarged by scanning the central light beam LC, and the third powder material P3 (actually only the first powder material in which the combined powder material is mixed) is added to the intermediate modeling object FC. The modeled object FF consisting of is added.

At the same time, in the irradiation range SSF on the front side in the scanning direction SD in the outside light irradiation range SS of the outside light beam LS, preheat treatment is performed as a pretreatment for the formation process of the molten pool MP, and the outside light irradiation range SS of the outside light beam LS is also performed. In the irradiation range SSB on the rear side in the scanning direction SD in, the heat retention process is performed as the post-process of the additional process of the modeled object FF.

That is, as shown in FIG. 10C, the control device 330 performs control to increase the peak LCP6 in the laser beam profile of the power density of the central light beam LC from the peak LSP6 in the laser beam profile of the power density of the outer light beam LS. .. The laser output of the central light beam LC is controlled to a temperature at which the third powder material P3 (the first powder material P1 mixed with the bonding powder material) is melted to form the molten pool MP. The laser output of the outer light beam LS is controlled so that the third powder material P3 (the first powder material mixed with the binding powder material) and the modeled object FF do not melt and reach a predetermined temperature.

As described above, in the irradiation range SSF on the front side in the scanning direction SD in the outside light irradiation range SS of the outside light beam LS, the preheat treatment is performed as the pretreatment for the formation process of the molten pool MP, so that the intermediate shaped object FC has a high temperature. Since it is in the state, it is not necessary to greatly increase the peak LCP6 in the laser beam profile of the power density of the central light beam LC.

Therefore, rapid heating by the central light beam LC can be reduced, and generation of spatter can be suppressed. Further, in the irradiation range SSB on the rear side of the scanning direction SD in the outside light irradiation range SS of the outside light beam LS, the heat retention process is performed as the post-treatment of the formation process of the molten pool MP, thereby suppressing rapid solidification of the modeled object FF. It is possible to prevent cracking.

(3-3. Operation of additional manufacturing device)
Next, the operation of adding the intermediate modeling object FC and the modeling object FF to the peripheral surface B2S of the one cylindrical member B2 of the base B by the additional manufacturing apparatus 300 will be described with reference to the flowchart of FIG. The controller 330 includes the peaks of the laser beam profiles of the central light beam LC and the outer light beam LS and the laser beam profiles of the respective power densities in the above-mentioned first, second, and third stages, the first-third powder material P1. -The supply amount of P3, the rotation speed and the movement speed of the base B, and the like are stored in advance.

First, since the control device 330 executes the above-described first step (preheat treatment of the peripheral surface B2S of the base B), the rotation and movement of the base B are started, and at the same time, the light irradiation device 120 is turned on ( Step S101 of FIG. 12). Specifically, the control device 330 drives the motors M1 and M2 to rotate the base B around the central axis C and moves in the central axis C direction (the other end direction of the peripheral surface B2S).

At the same time, the control device 330 turns on the central light beam light source 122 to irradiate the central light beam LC from the central light beam irradiation unit 121 to the peripheral surface B2S of the base B, and also turns on the outer light beam light source 124 to the outside. The outer light beam LS is irradiated from the light beam irradiation unit 123 onto the peripheral surface B2S of the base B, and preheat treatment is performed at the initial stage of the peripheral surface B2S of the base B.

Then, the control device 330 determines whether or not the initial preheat treatment for the peripheral surface B2S of the base B is completed (step S102), and when the initial preheat treatment is completed, the light irradiation device 120 is turned off. The base B is returned to the start position of the first stage, and the rotation and movement of the base B are stopped (step S103). Next, the control device 330 turns on the additional material supply device 310 to start the rotation and movement of the base B, and at the same time, performs the light irradiation in order to execute the above-described second step (addition processing of the intermediate modeling object FC). The device 120 is turned on (step S104).

Specifically, the control device 330 appropriately opens and closes the powder introduction valves 113a and 113b of the component ratio adjusting device 113 to adjust the component ratio of the first powder material P1 and the second powder material P2 to adjust the third powder material. P3. Then, the gas introduction valve 113d and the powder supply valve 113c are opened, and the third powder material P3 is injected from the injection nozzle 115 to the peripheral surface B2S of the base B by the high pressure nitrogen from the gas cylinder 114 and is supplied.

Then, the control device 330 drives the motors M1 and M2 to rotate the base B around the central axis C and moves in the central axis C direction (the other end direction of the peripheral surface B2S). At the same time, the central light beam light source 122 is turned on to irradiate the central light beam LC from the central light beam irradiation unit 121 to the peripheral surface B2S of the base B, and the outer light beam light source 124 is turned on to the outer light beam irradiation unit 123. The outer light beam LS is irradiated onto the peripheral surface B2S of the base B to execute the addition processing of the intermediate modeling object FC.

Then, the control device 330 determines whether or not the addition processing of the intermediate shaped object FC to the peripheral surface B2S of the base B is completed (step S105), and when the addition processing of the intermediate shaped object FC is completed, the light irradiation is performed. The device 120 is turned off, the base B is returned to the start position of the second stage, and the rotation and movement of the base B are stopped (step S106).

Next, the control device 330 turns on the additional material supply device 310 to start the rotation and movement of the base B in order to execute the above-mentioned third step (addition processing of the modeled object FF), and at the same time, the light irradiation device. 120 is turned on (step S107). Specifically, the control device 330 appropriately opens and closes the powder introduction valve 113a while keeping the powder introduction valve 113b of the component ratio adjusting device 113 closed to make only the first powder material P1 the third powder material P3. Then, the gas introduction valve 113d and the powder supply valve 113c are opened, and the third powder material P3 is injected from the injection nozzle 115 to the peripheral surface B2S of the base B by the high pressure nitrogen from the gas cylinder 114 and is supplied.

Then, the control device 330 drives the motors M1 and M2 to rotate the base B around the central axis C and moves in the central axis C direction (the other end direction of the peripheral surface B2S). At the same time, the central light beam light source 122 is turned on to irradiate the central light beam LC from the central light beam irradiation unit 121 to the peripheral surface B2S of the base B, and the outer light beam light source 124 is turned on to the outer light beam irradiation unit 123. Then, the outer light beam LS is irradiated onto the peripheral surface B2S of the base B, and the addition process of the modeled object FF is executed.

Then, the control device 330 determines whether the process of adding the model FF to the intermediate model FC added to the peripheral surface B2S of the base B is completed (step S108), and the process of adding the model FF is completed. Then, the additional material supply device 310 and the light irradiation device 120 are turned off, the rotation and movement of the base B are stopped (step S109), and all the processes are ended.

(3-4. Effect of the third embodiment)
According to the third embodiment described above, the additional material supply device 310 has the component ratio adjusting device 113 that adjusts the component ratios of the plurality of types of powder materials. This makes it possible to easily form the intermediate shaped article FC as a graded layer whose components are adjusted in the radial direction.

Further, according to the additive manufacturing apparatus 300 of the third embodiment, the powder material of which the component ratio has been adjusted with respect to the base B has the component ratio adjusting device 113 which adjusts the component ratio of plural kinds of powder materials. An additional material supply device 310 for spraying and supplying, a light irradiation device 120 for irradiating a light beam to a powder material supply portion whose component ratio in the base B has been adjusted, and a powder supply and light supply for the additional material supply device 310. The controller 330 controls the light irradiation of the irradiation device 120 and controls the relative scanning of the light beam with respect to the base B.

The light irradiation device 120 includes a central light beam irradiation unit 121 that irradiates a central light beam LC as a light beam to the center of a powder material supply unit whose component ratio has been adjusted, and an outer light beam as a light beam outside the central light beam LC. It has an outer light beam irradiation unit 123 that irradiates LS. Then, the control device 330 adds the intermediate shaped object FC whose component ratio gradually changes in the thickness direction to the surface of the base B, and when forming the intermediate shaped object FC, the central light beam is changed according to the change of the component ratio. The output condition of the irradiation unit 121 and the output condition of the outer light beam irradiation unit 123 are independently controlled.

With such a configuration, the difference in the coefficient of thermal expansion between the peripheral surface B2S (carbon steel (S45C)) of the base B and the intermediate shaped article FC causes the boundary between the peripheral surface B2S of the base B and the intermediate shaped article FC to be the same. It can be formed so as to gradually decrease as it approaches. Further, the portion of the intermediate shaped article FC near the shaped article FF can contain a large amount of the first powder material (tungsten carbide (WC)). Therefore, the difference in the coefficient of thermal expansion between the intermediate shaped article FC and the shaped article FF (tungsten carbide (WC)) can be gradually reduced as it approaches the boundary between the intermediate shaped article FC and the shaped article FF. Accordingly, by adding the intermediate shaped article FC to the base B and the shaped article FF to the intermediate shaped article FC, it is possible to significantly suppress the occurrence of cracks due to the difference in thermal expansion coefficient.

Further, according to the third embodiment, when adding the intermediate shaped object FC, the control device 330 sets the peak LSP5 in the beam profile of the power density of the outer light beam LS to the beam profile of the power density of the central light beam LC. Increase above LCP5 from peak. As described above, when the intermediate shaped object FC is added, the power density of the central light beam LC is low, so that it is possible to suppress the occurrence of spatter due to excessive heat input of the central light beam LC. Further, since a large amount of energy can be input as the entire laser output while suppressing the peak LCP5, it is possible to add the intermediate shaped object FC at high speed while suppressing the generation of spatter.

Further, according to the third embodiment, when adding the modeled object FF (upper modeled object), the control device 330 sets the peak LCP6 in the beam profile of the power density of the central light beam LC to the power density of the outer light beam LS. The peak LSP6 in the beam profile of No. 2 is increased by the central light beam LC to perform the formation process of the molten pool MP of the base B in the central light irradiation range CS and the melting process of the powder material whose ratio has been adjusted, and the outside light. Pre-heat treatment is performed as a pretreatment for the formation process of the molten pool MP on the front side in the scanning direction of the beam LS, and heat retention treatment is performed as a post-treatment for the formation process of the molten pool MP on the rear side in the scanning direction of the outer light beam LS. To do. Accordingly, preheat treatment, formation of the molten pool MP, and heat retention treatment for the molten pool MP can be easily and efficiently performed in the scanning direction of the outer light beam LS and the central light beam LC.

<4. Other>
According to the first, second, and third embodiments, the outer light beam irradiation unit 123 irradiates a ring-shaped light beam as the outer light beam LS. As a result, the central light beam LC can be easily arranged in front, rear, left, and right at equal intervals, which contributes to cost reduction.

In addition, in the first embodiment, the light irradiation device 120 is configured to include the central light beam irradiation unit 121, the central light beam light source 122, the outer light beam irradiation unit 123, and the outer light beam light source 124. However, as shown in FIG. 13, the light irradiation device 120 includes a front light beam irradiation unit (outer light beam irradiation unit) 125 and a front light beam light source 126 instead of the outer light beam irradiation unit 123 and the outer light beam light source 124. A rear light beam irradiation unit (outer light beam irradiation unit) 127 and a rear light beam light source 128 may be provided.

The front light beam irradiation unit 125 irradiates the front light beam FLS (outer light beam, first light beam Be1) having a circular irradiation shape (front light irradiation range FSS) on the front side of the central light beam LC in the scanning direction SD. To do. The rear side light beam irradiation unit 127 has a rear side light beam BLS (outside light beam, second light beam) that has a circular irradiation shape (rear side light irradiation range BSS) on the rear side in the scanning direction SD of the central light beam LC. Be2) is irradiated. Then, in the front side light irradiation range FSS of the front side light beam FLS, preheat treatment is performed as a pre-treatment of the formation process of the molten pool MP, and in the rear side light irradiation range BSS of the rear side light beam BLS, the additional processing of the modeled object FF is performed. A heat retention process is performed as a post-process. In the second and third embodiments as well, similar to the above, it is possible to provide an irradiation unit that respectively irradiates the first light beam Be1 to the fourth light beam Be4 separately.

In the first to third embodiments described above, the case where the modeled object FF is composed of a large amount of the first powder material P1 and a small amount of the combined powder material has been described, but only the first powder material P1 that does not include the combined powder material. Also in the case of, it can be added as in the present example. In addition, when a molded object made of a hard material other than tungsten carbide (WC) is added to the base B made of a soft material, the soft material and the hard material components are not included without including the binding powder material. It is also possible in the same manner as in the third embodiment to adjust the ratio in the same manner as in the third embodiment, add the intermediate shaped article, and add the shaped article made of only the hard material without including the binding powder material. ..

Further, in the third embodiment described above, the intermediate model FC and the model FF added to the base B are made of different materials, but the same applies to the case of the same material. In that case, it is not necessary to add the intermediate shaped article FC. Further, even if the materials are not the same material but have similar thermal expansion coefficients, it is not necessary to add the intermediate modeling object FC.

Further, in the first to third embodiments described above, the powder material is jetted and supplied to the base B by the additional material supply devices 110 and 310, but the present invention is not limited to this mode, and is made of a linear metal material. For example, the modeling object FF may be added to the base B by supplying a wire or the like with an additional material supply device. With this, the same effect as that of the above embodiment can be expected.

100, 200, 300; additional manufacturing device, 110, 310; additional material supply device, 113; component ratio adjusting device, 120; light irradiation device, 121; central light beam irradiation unit, 123; outer light beam irradiation unit, 130, 230, 330; control device, B; base, P1; first powder material, P2; second powder material, P3; third powder material, Be1; first light beam, Be2; second light beam, Be3; Three light beams, Be4; Fourth light beam, FC; Intermediate modeling object, FF; Modeling object, L1; Predetermined distance, LC; Central light beam, SC1; First scan, SC2; Second scan, SC3; Third scanning.

Claims (11)

An additional manufacturing apparatus for adding a shaped article to a base using powder material or linear material,
An additional material supply device that sprays and supplies the powder material to the base, or supplies the linear material,
A light irradiation device for irradiating a light beam to the powder material or the linear material supply portion in the base,
A controller for controlling the powder supply of the additional material supply device or the supply of the linear material, and the light irradiation of the light irradiation device, and controlling the relative scanning of the light beam with respect to the base.
Equipped with
The light irradiation device includes a central light beam irradiation unit that irradiates a central light beam as the light beam to the center of the powder material supply unit or the linear material supply unit, and an outside of the central light beam as the light beam. It has an outer light beam irradiation unit that irradiates a light beam,
The control device controls the output condition of the central light beam irradiation unit and the output condition of the outer light beam irradiation unit independently to determine the peak in the beam profile of the power density of the central light beam to the outer light beam. An additional manufacturing apparatus for adding the shaped article above the peak of the power density beam profile. The control device is
Performing the first forming treatment of the first molten pool and the first melting treatment of the powder material or the linear material in the central light irradiation range of the base with the central light beam,
Performing a first preheat treatment as a pretreatment for the first forming treatment of the first molten pool with the first light beam on the front side in the direction of the scanning of the outer light beam,
The additional manufacturing apparatus according to claim 1, wherein a first heat retention process is performed as a post-process for the first formation process of the first molten pool with the second light beam on the rear side in the scanning direction of the outer light beam. In the scanning of the light beam,
The scanning by the central light beam is defined as the second scanning,
The scanning by the third light beam, which is the outer light beam on one side of the left and right sides in the scanning direction of the central light beam, is defined as the first scanning,
When the scanning by the fourth light beam, which is the outer light beam on the other side of the left and right sides in the scanning direction of the central light beam, is defined as the third scanning,
The control device is
Scanning the central light beam and the outer light beam in the same direction by a predetermined distance,
The second forming process of the second molten pool in the central light irradiation range of the base with the central light beam in the second scanning, and the second melting process of the powder material or the linear material,
Performing a second preheat treatment as a pretreatment for the second formation treatment of the second molten pool with the third light beam in the first scan, and
After performing a second heat retention treatment as a post-treatment for the second formation treatment of the second molten pool with the fourth light beam in the third scan,
The second scanning performed by the central light beam next time is such that the central light beam and the outer light beam are adjacent to each other in the same direction on the one side with the second scanning performed this time. The additional manufacturing apparatus according to claim 1 or 2, which scans only. The additional manufacturing apparatus according to claim 3, wherein the scanning directions of the central light beam and the outer light beam this time are the same as the scanning directions of the central light beam and the outer light beam next time. The predetermined distance is
During the predetermined distance, the central light beam performs the second forming process and the second melting process of the second molten pool by the second scanning of this time, and then the second beam of the next time. For the scanning, the scanning is moved to the one side of the base on which the second preheat treatment has been completed by the first scanning by the third light beam this time, and,
During the predetermined distance, the fourth light beam scans the other side of the base by the third scan of this time to perform the second heat retention process, and then the third scan of the next time. Therefore, when the scanning is moved to the range where the second molten pool is formed by the second scanning by the central light beam this time,
The additional manufacturing apparatus according to claim 3 or 4, wherein the temperature of the molten metal in the second molten pool is set to a distance that is equal to or higher than a predetermined temperature. The additional manufacturing apparatus according to claim 5, wherein the predetermined temperature is a solidification temperature of a molten metal melted in the second molten pool. The additive manufacturing apparatus according to any one of claims 1 to 6, wherein the additional material supply device includes a component ratio adjusting device that adjusts a component ratio of a plurality of types of powder materials. An additional manufacturing apparatus for adding a molded article to a base using a plurality of types of powder materials,
An additional material supply device that has a component ratio adjusting device that adjusts the component ratio of the plurality of types of powder materials, and that supplies the powder material with the component ratio adjusted to the base by spraying.
A light irradiation device for irradiating a light beam to the supply portion of the powder material in which the component ratio in the base has been adjusted,
A control device for controlling the powder supply of the additional material supply device and the light irradiation of the light irradiation device, and controlling the relative scanning of the light beam with respect to the base.
Equipped with
The light irradiation device includes a central light beam irradiation unit that irradiates a central light beam as the light beam at the center of the powder material supply unit whose component ratio has been adjusted, and outside light as the light beam outside the central light beam. Having an outer light beam irradiation unit for irradiating a beam,
The control device adds an intermediate shaped object in which the component ratio gradually changes in the thickness direction to the surface of the base, and when forming the intermediate shaped object, the central light beam is changed according to the change in the component ratio. An additional manufacturing apparatus for independently controlling an output condition of an irradiation unit and an output condition of the outer light beam irradiation unit. The control device increases the peak in the beam profile of the power density of the outer light beam more than the peak in the beam profile of the power density of the central light beam when adding the intermediate modeling object. Additional manufacturing equipment. The control device increases the peak in the beam profile of the power density of the central light beam more than the peak in the beam profile of the power density of the outer light beam when adding a modeled object, and irradiates the central light beam with the central light. As a pretreatment of the formation process of the molten pool on the front side of the scanning direction in the outer light beam, the formation process of the molten pool of the base in the range and the melting process of the powder material whose component ratio has been adjusted. The additional manufacturing apparatus according to claim 8 or 9, which performs a preheat treatment and a heat retention treatment as a post-treatment of the molten pool formation treatment on the rear side in the scanning direction of the outer light beam. The additional manufacturing apparatus according to claim 1, wherein the outer light beam irradiation unit irradiates a ring-shaped light beam as the outer light beam.

Images