JP2008133497A - Method for producing three-dimensional structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a three-dimensional structure by irradiating a metallic material with a light beam, which does not cause the segregation of a component in the material, makes the density of the material uniform, and makes the material to be easily handled. <P>SOLUTION: The method for producing the three-dimensional structure comprises the steps of: irradiating a metal gauze 2 formed of a metal wire with the light beam (L) to form a solidified layer or a melted layer; and stacking the layers for producing the three-dimensional structure by repeating the irradiation step on the metal gauze. Because the material has a shape of the metal gauze 2, the structure does not cause the segregation of the component in the material, gives the uniform density to the material, and is easily handled. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a three-dimensional shaped object in which a metal material is irradiated with a light beam.

  Conventionally, a material layer formed of a metal material is irradiated with a light beam (directional energy beam, for example, laser light) to form a sintered layer or a molten layer, and a new material is formed on the sintered layer or the molten layer. A technique for manufacturing a three-dimensional shaped object by repeating the formation of a sintered layer or a molten layer by forming a layer and irradiating a light beam is known. A feature of this technique is that a complicated three-dimensional shape can be manufactured in a short time. By irradiating a light beam with high energy density, the metal material is almost completely melted and then solidified, that is, the material density after melting is almost 100%, and the surface of this high-density model is finished. Thus, a smooth surface can be formed, which is applied to a plastic mold or the like.

  In this technique called metal stereolithography, the metal material normally used is used in a powder state. By making the material to be laminated a metal powder, the surface area of the material increases and the absorption rate of the laser beam also increases, so it is possible to sinter or melt the material even under irradiation conditions with low energy density, improving the modeling speed To do.

  In order to obtain a modeled object having a certain level of strength, in the material layer to which the laser beam is irradiated, the adhesion strength between the modeled part adjacent to the laser beam scanning position is increased, and the modeled layer that is irradiated and the modeled layer underneath it Adhesion strength with must also be increased. If the material to be laminated is a metal powder, the lower modeling layer is irradiated with laser light through a gap between the powders, and the lower modeling layer is also heated to improve the adhesion strength.

  Furthermore, the upper surface of the laser-irradiated portion should not rise so much. When the next material layer for modeling the next layer is formed, if the raised height is equal to or greater than the thickness for laminating the metal powder, formation of the material layer itself becomes difficult.

  Of course, the appearance of the shaped object must not be cracked, and it is desirable that the internal structure be free of microcracks.

  Here, a part or all of the metal material irradiated with the laser is once melted and then cooled and solidified to form a modeled object. If the wettability at the time of the melting is large, it is possible to join the adjacent modeled part. If the area is large and the fluidity is large, the rise is small. Therefore, it is desirable that the fluidity when melted is large and the wettability is good.

  From such a viewpoint, as shown in Patent Document 1, the present applicant proposed a mixed powder for metal stereolithography made of iron-based powder made of chromium molybdenum steel, nickel powder, and phosphorous copper or manganese copper powder. did. Chrome molybdenum steel powder is adopted from the viewpoint of hardness and strength, nickel powder is adopted from the viewpoint of strength, toughness and workability, and phosphorous copper or manganese copper powder is adopted from the viewpoint of wettability and fluidity.

  It is difficult to produce a high-density three-dimensional shaped object by irradiating only iron-based powder with laser light. This is because it is difficult to integrate the next modeling layer into the previously formed iron modeling layer without creating a gap. Even if the chromium molybdenum steel itself has high hardness and excellent mechanical strength, the modeling density of the three-dimensional structure obtained by laser irradiation with only the chromium molybdenum steel powder is low and its strength is also weak.

  In the case where the iron-based powder is an alloy containing a large amount of nickel component, the above-mentioned problem becomes serious because a strong oxide film formed on the surface of the powder hinders fusion integration of the iron-based powders. Inclusion of nickel in an iron-based metal has the advantage that the toughness, strength, and corrosion resistance of the iron-based metal can be improved, but when used for the production of a three-dimensional structure by laser irradiation, the advantage is completely absent. It is not demonstrated.

  If the energy of laser irradiation is increased, even iron-based powders containing chromium-molybdenum steel and nickel components can be sufficiently fused and integrated, but in that case, the laser irradiation device becomes too large or excessive power is required. In addition to the disadvantage that the manufacturing cost is high, the scanning speed of the laser beam cannot be increased, and the manufacturing efficiency is lowered. In addition, a shaped article made with an excessive amount of irradiation energy tends to warp or deform due to thermal stress.

  Copper is a metal material that has good fluidity when melted, good wettability with an iron-based material in a molten state, and hardly deteriorates in characteristics even when alloyed with an iron-based material. When the mixed powder composed of iron-based powder and copper alloy powder is irradiated with laser light, the copper alloy is melted first to fill the gap between the iron-based powders, and at the same time, this becomes a binder and is fused and integrated. When the irradiation energy of laser light is high, all iron-based powder and copper alloy powder forming the mixed powder are melted to form an alloy.

  The fluidity of the molten metal becomes better as the difference between the melting temperature and the melting point increases. Phosphorous copper alloys and manganese copper alloys have lower melting points than pure copper, and the fluidity when irradiated with the same energy is better for phosphorous copper alloys and manganese copper alloys than for pure copper.

  The conventional iron-based powder material for metal stereolithography also includes nickel powder. As described above, when the iron-based powder is an alloy containing a nickel component, fusion integration between the powders is hindered by a strong oxide film formed on the powder surface. When nickel powder is mixed with a copper alloy as a separate powder, fusion and integration of these powders are performed well. And the hardened layer which consists of an iron-type component, nickel, and a copper alloy component has the high sintered density, As a result, toughness and intensity | strength become high.

  In particular, when the blending amount of chromium molybdenum steel is 60 to 90% by weight, the blending amount of nickel powder is 5 to 35% by weight, and the blending amount of copper manganese alloy powder is 5 to 15% by weight, particularly preferable results are obtained. Can do.

  In the metal stereolithography using the above-described metal powder as a material, a generally preferable result can be obtained in that a complicated three-dimensional shaped object is obtained by laser irradiation and its lamination.

  However, the metal powder material has a certain particle size distribution and a difference in shape, and the powder packing density when the powder is spread thinly with a uniform thickness is not constant, and a mixed powder consisting of a plurality of powders having different components If used, there is a risk of segregation of components.

In addition, when using powder with a small particle size, handling is not good, for example, when the powder is handled by an operator, and the powder that has sowed accumulates in the modeling equipment and causes mechanical problems. There is a risk of causing.
JP-A-2005-48234

  The present invention has been made to solve the above-described problems, and has no segregation of components in the material, the material density is constant, and the method for producing a three-dimensional shaped article that is easy to handle the material is easy. The purpose is to provide.

  In order to achieve the above object, the invention of claim 1 is directed to a method of manufacturing a three-dimensional shaped object by irradiating a metal material with a light beam to produce a three-dimensional shaped object in a wire mesh formed by a metal wire. An irradiation step of irradiating a beam to form a solidified layer or a dissolved layer; and a lamination step of manufacturing the three-dimensional shaped object by laminating the solidified layer or the dissolved layer by repeating the irradiation step on a wire mesh. , With.

  The invention of claim 2 is the method for producing a three-dimensional shaped article according to claim 1, wherein the metal wire has a wire diameter of 0.01 mm or more and 0.1 mm or less.

  According to a third aspect of the present invention, in the method for manufacturing a three-dimensionally shaped article according to the first or second aspect, the gap between the metal wires in the wire mesh is 0.01 mm or more and 0.1 mm or less.

  The invention of claim 4 is the method for producing a three-dimensional shaped object according to any one of claims 1 to 3, wherein the wire mesh is an iron-based metal wire, a nickel metal wire, and a nickel-based alloy metal. Both or one of the wires and both or one of the copper metal wire and the copper-based alloy metal wire are included.

  According to a fifth aspect of the present invention, in the method for manufacturing a three-dimensional shaped article according to the fourth aspect, the wire mesh has a composition ratio of the iron-based metal wire of 60 wt% or more and 90 wt% or less, and a nickel metal wire And the composition ratio of either or both of the nickel-based alloy metal wire is 5% by weight or more and 35% by weight or less, and the composition ratio of either or both of the copper metal wire and the copper-based alloy metal wire is 5% by weight or more. It is 15% by weight or less.

  The invention of claim 6 is the method for producing a three-dimensional shaped article according to any one of claims 1 to 5, wherein the wire mesh is a wire mesh made of an iron-based metal wire, a nickel metal wire, and nickel. A wire mesh made of both or any one of the alloy metal wires and a wire mesh made of either or both of the copper metal wires and the copper alloy metal wires are overlapped.

  Invention of Claim 7 is obtained by laminating | stacking until then in the manufacturing method of the three-dimensional shaped molded article as described in any one of Claim 1 thru | or 6, after formation of the said solidification layer or melt | dissolution layer. Further, a cutting process for cutting and removing the surface portion and / or unnecessary portion of the three-dimensional shaped object is further provided.

  According to the first aspect of the present invention, since a light beam is irradiated onto a metal mesh formed of a metal wire, it is possible to manufacture a three-dimensional shaped object with no segregation of components and a constant material density. Moreover, since handling of material is easy, it is easy to manufacture a three-dimensional shaped article.

  According to invention of Claim 2, since the wire diameter of a metal wire is thin, the dimensional accuracy of a three-dimensional shaped molded article is good. Moreover, since the wire diameter of the metal wire is not too thin, the material does not scatter during the light beam irradiation.

  According to the invention of claim 3, since the light beam irradiates and heats the lower solidified layer, the adhesion strength with the lower solidified layer is improved.

  According to the invention of claim 4, the rise of the solidified layer is reduced, and the metal net to be laminated next can be arranged with high accuracy.

  According to invention of Claim 5, generation | occurrence | production of the crack in the external appearance of the three-dimensional shape molded article manufactured and the micro crack of an internal structure | tissue are suppressed.

  According to the sixth aspect of the present invention, since a single metal mesh is not composed of a plurality of metal wires, a plurality of types of metal mesh composed of a single material metal wire is used in combination. The cost is low and the compounding ratio of the materials can be easily changed.

  According to invention of Claim 7, the surface roughness of the three-dimensional shape molded article manufactured becomes fine, and a dimensional accuracy improves.

(First embodiment)
A method for manufacturing a three-dimensional shaped object according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of a metal stereolithography machine used for manufacturing a three-dimensional shaped object, and FIG. 2 shows a configuration of a wire mesh used for the material. The metal stereolithography machine 1 includes a modeling base 3 on which a metal mesh 2 as a material is placed, a lifting table 4 that holds the modeling base 3 and moves up and down, and a light beam transmitter that emits a light beam L. 5 and a galvanometer mirror 6 for scanning the light beam L on the wire mesh 2.

  The metal mesh 2 is composed of metal wires 21 arranged in the vertical direction and the horizontal direction, and the metal wires 21 are joined to each other by electric welding. The wire diameter A of the metal wire 21 is 0.01 to 0.1 mm, and the interval B between the metal wires 21 is 0.01 to 0.1 mm. The metal wire 21 includes an iron metal wire 21a, a nickel metal wire 21b and / or a nickel alloy metal wire 21c, and a copper metal wire 21d and / or a copper alloy metal wire 21e. The composition ratio of the iron-based metal wire 21a is 60 to 90% by weight, the composition ratio of the nickel metal wire 21b and / or the nickel-based alloy metal wire 21c is 5 to 35% by weight, and the copper metal wire 21d and / or Alternatively, the composition ratio of the copper-based alloy metal wire 21e is 5 to 15% by weight.

  FIG. 3 shows the flow of the manufacturing method according to this embodiment, and FIG. 4 shows the operation of the manufacturing method. First, the lifting table 4 is lowered by a length D corresponding to the thickness of the wire mesh 2 (S1), and the wire mesh 2 is placed on the modeling base 3 (S2) (see FIG. 4A). A light beam L is emitted from the light beam transmitter 5 (S3), and the light beam L is scanned to an arbitrary position on the wire mesh 2 by the galvanometer mirror 6 (S4), and the wire mesh 2 is melted and solidified to form a base 3 for modeling. (S5) (see FIG. 4B). S1 to S5 constitute an irradiation process. Then, it is determined whether or not the modeling is completed (S6), and S1 to S5 are repeated until the modeling is completed (see FIG. 4C). S1 to S6 constitute a stacking process. Thus, a three-dimensional shaped object is manufactured by laminating the solidified layer (see FIG. 4D).

  In the manufacturing method described above, since the material is the wire mesh 2, there is no segregation of components or variations in material density, and it is possible to manufacture a three-dimensional shaped object with a constant composition and metal structure. Moreover, since it does not scatter like metal powder, the handleability of material is good and it is easy to manufacture a three-dimensional shaped article. Since the wire diameter of the metal wire 21 is thin, the dimensional accuracy of the three-dimensional shaped object is good, and since it is not too thin, the material does not scatter during the light beam irradiation. Since the distance between the metal wires 21 is not too wide, the density of the material is not low and is not too narrow. Therefore, the light beam L irradiates and heats the lower shaped layer well, and a new solidified layer and the lower shaped layer are formed. The adhesion strength with is increased.

  The metal wire 21 is composed of an iron-based metal wire 21a, a nickel metal wire 21b and / or a nickel-based alloy metal wire 21c, and a copper metal wire 21d and / or a copper-based alloy metal wire 21e. The swell is reduced, and the metal net to be laminated next can be arranged with high accuracy. The composition ratio of the iron-based metal wire 21a is 60 to 90% by weight, the composition ratio of the nickel metal wire 21b and / or the nickel-based alloy metal wire 21c is 5 to 35% by weight, and the copper metal wire 21d and / or Alternatively, since the composition ratio of the copper-based alloy metal wire 21e is 5 to 15% by weight, the appearance crack of the manufactured three-dimensional shaped object and the occurrence of microcracks in the internal structure can be suppressed.

  The wire mesh 2 that is the material of the three-dimensional shaped object may be created for each type of the metal wire 21. FIG. 5 shows a manufacturing method using the wire mesh 2 for each type of the metal wire 21. Wire mesh 2a made from iron metal wire 21a, wire mesh 2bc made from nickel metal wire 21b and / or nickel alloy metal wire 21c, wire mesh 2de made from copper metal wire 21d and / or copper alloy metal wire 21e Are placed on the modeling base 3 and irradiated with the light beam L to form a three-dimensional shaped object. The iron-based metal wire 21a is 60 to 90% by weight, the nickel metal wire 21b and / or the nickel-based alloy metal wire 21c is 5 to 35% by weight, the copper metal wire 21d and / or the copper-based alloy metal. The wire mesh 2 is combined so that the line 21e is 5 to 15% by weight. Creation of the wire mesh 2 is simple and low cost. Moreover, the compounding ratio of the materials can be easily changed.

(Second Embodiment)
A method for manufacturing a three-dimensional shaped object according to the second embodiment of the present invention will be described. FIG. 6 shows the flow of the manufacturing method according to the present embodiment, and FIG. 7 shows the operation of the manufacturing method. In the present embodiment, the wire mesh 22 is long and wound around an unwinding roll 71, and an unwinding roll 71 and a winding roll 72 are set on both sides of the metal stereolithography machine 1. First, the elevating table 4 is lowered by a length D corresponding to the thickness of the wire mesh 22 (S21), and the wire mesh 22 necessary for optical modeling is sent from the unwinding roll 71 to the take-up roll 72 to the modeling base 3. The wire mesh 2 is placed (S22) (see FIG. 7A). A light beam L is emitted from the light beam transmitter 5 (S23), the light beam L is scanned to an arbitrary position on the wire mesh 2 by the galvanometer mirror 6 (S24), and the wire mesh 2 is melted and solidified to form a base 3 for modeling. (S25 (see FIG. 7B)) At this time, the modeled object and the wire net 2 are separated by the light beam L. Then, it is determined whether or not the modeling is completed (S26). Then, S21 to S25 are repeated until it is determined that the modeling is completed, and a three-dimensional shaped object is manufactured by laminating the solidified layers (see FIG. 7C). Can be low cost.

  The wire mesh 22 that is the material of the three-dimensional shaped object may be created for each type of the metal wire 21. FIG. 8 shows a manufacturing method using the wire mesh 2 for each type of the metal wire 21. From the unwinding roll 71a, the wire mesh 22a of the iron-based metal wire 21a, from the unwinding roll 71b the metal wire 22bc of the nickel metal wire 21b and / or the nickel-based alloy metal wire 21c, and from the unwinding roll 71c to the copper metal wire 21d. And / or the wire mesh 22 de of the copper-based alloy metal wire 21 e is sent out, placed on the modeling base 3, and taken up by the take-up roll 72. Creation of the wire mesh 22 is simple and low cost. Moreover, the compounding ratio of the materials can be easily changed.

(Third embodiment)
A method for manufacturing a three-dimensional shaped object according to the third embodiment of the present invention will be described. In addition to the manufacturing method according to the first embodiment, the method for manufacturing a three-dimensional modeled object according to the present embodiment includes a step of cutting the periphery of the modeled object. FIG. 9 shows a configuration of the metal stereolithography combined processing machine 8 used in the manufacturing method according to the present embodiment. In addition to the metal stereolithography processing machine 1 according to the first embodiment, the metal stereolithography combined processing machine 8 is a milling head 81 that cuts the periphery of a modeled object, and an XY drive mechanism 82 that moves the milling head 81 to a cutting location. And have. The milling head 81 has a tool (ball end mill) having a diameter of 0.6 mm (effective blade length of 1 mm), and the milling head 81 is operated when the thickness of the solidified layer becomes 0.5 mm.

  FIG. 10 shows the flow of the manufacturing method according to the present embodiment, and FIG. 11 shows the operation of the manufacturing method 8. First, the modeling base 3 is lowered by a length D corresponding to the thickness of the metal mesh 2 (S31), and the metal mesh 2 is placed on the modeling base 3 (S32). A light beam L is emitted from the light beam transmitter 5 (S33), and the light beam L is scanned to an arbitrary position on the wire mesh 2 by the galvanometer mirror 6 (S34), and the wire mesh 2 is melted and solidified to form a base 3 for modeling. A solidified layer integrated with (S35) is formed. It is determined whether the thickness of the solidified layer has reached 0.5 mm (S36), and steps S31 to S35 are repeated until the solidified layer has reached 0.5 mm, thereby laminating the solidified layer.

  When the thickness of the laminated solidified layer becomes 0.5 mm, the milling head 81 is driven (S37). The milling head 81 is moved in the directions of the arrow X and the arrow Y by the XY drive mechanism 82, and the surface of the modeled object on which the solidified layer is laminated is cut (S38). S37 and S38 constitute a cutting process. Then, it is determined whether the modeling of the three-dimensional shaped object has been completed (S39). If it is determined that the modeling has not been completed, the process returns to the powder layer forming step (S31). In this way, the three-dimensional shaped object is manufactured by repeating S31 to S38 and laminating the solidified layer. The surface roughness of the manufactured three-dimensional shaped object becomes fine, and the dimensional accuracy is improved.

  In addition, this invention is not restricted to the structure of the said various embodiment, A various deformation | transformation is possible in the range which does not change the meaning of invention. For example, the metal mesh 2 may be created by knitting the metal wire 21 or may be created by joining the metal wire 21 by pressure bonding. In the wire mesh 2, the metal wires 21 may be combined in three directions instead of two directions.

The perspective view of the metal stereolithography processing machine used for the manufacturing method which concerns on the 1st Embodiment of this invention. The block diagram of the wire mesh used for the manufacturing method. The flowchart of the manufacturing method. The figure explaining the manufacturing method in time series. The figure explaining the modification of the manufacturing method. The flowchart of the manufacturing method which concerns on the 2nd Embodiment of this invention. The figure explaining the manufacturing method in time series. The figure explaining the modification of the manufacturing method. The perspective view of the metal stereolithography machine used for the manufacturing method which concerns on the 3rd Embodiment of this invention. The flowchart of the manufacturing method. The figure explaining the manufacturing method in time series.

Explanation of symbols

2, 2a, 2bc, 2de wire mesh 21, 21a, 21b, 21c, 21d, 21e metal wire

Claims (7)

In the manufacturing method of a three-dimensional shaped object that irradiates a metal material with a light beam to produce a three-dimensional shaped object,
An irradiation step of irradiating a wire mesh formed of a metal wire with a light beam to form a solidified layer or a dissolved layer;
A method for producing a three-dimensional shaped article comprising: a laminating step for producing the three-dimensional shaped article by laminating the solidified layer or the dissolved layer by repeating the irradiation step on a wire mesh.   The method for producing a three-dimensional shaped article according to claim 1, wherein a diameter of the metal wire is 0.01 mm or more and 0.1 mm or less.   The method for producing a three-dimensional shaped article according to claim 1 or 2, wherein a gap between the metal wires in the wire mesh is 0.01 mm or more and 0.1 mm or less.   The wire mesh has an iron metal wire, a nickel metal wire and / or a nickel alloy metal wire, and a copper metal wire and / or a copper alloy metal wire. The manufacturing method of the three-dimensional shape molded article as described in any one of Claim 1 thru | or 3.   In the wire mesh, the composition ratio of the iron-based metal wire is 60 wt% or more and 90 wt% or less, and the composition ratio of either or both of the nickel metal wire and the nickel-based alloy metal wire is 5 wt% or more and 35 wt%. The three-dimensional shaped object according to claim 4, wherein the composition ratio of both or one of the copper metal wire and the copper-based alloy metal wire is 5 wt% or more and 15 wt% or less. Production method.   The wire mesh is composed of a wire mesh made of an iron-based metal wire, a wire mesh made of either or both of a nickel metal wire and a nickel-based alloy metal wire, and both or either of a copper metal wire and a copper-based alloy metal wire. A method for producing a three-dimensional shaped object according to any one of claims 1 to 5, wherein a metal mesh is overlapped.   2. The method according to claim 1, further comprising a cutting step of cutting and removing a surface portion and / or an unnecessary portion of the three-dimensionally shaped object obtained by forming the solidified layer or the dissolved layer. The manufacturing method of the three-dimensional shape molded article as described in any one of Claims 1 thru | or 6.

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