JP4737007B2 - Metal powder for metal stereolithography - Google Patents

Description

  The present invention relates to a metal powder for metal stereolithography that obtains a three-dimensional shaped object by irradiating a metal powder with a light beam.

  Conventionally, a powder layer of metal powder is irradiated with a light beam (eg, a directional energy beam such as a laser beam) to form a sintered layer, and a new powder layer is laid on the sintered layer to form a light beam. A metal stereolithography technique is known in which a three-dimensional shaped article is manufactured by repeating the process of forming a sintered layer. According to this technique, a complicated three-dimensional shaped object can be manufactured in a short time. By irradiating with a light beam with high energy density, the metal powder is completely melted and then solidified, so that the sintered density becomes almost 100%, and the surface of this high-density model is finished and smoothed. By making it a smooth surface, it can be applied to plastic molds and the like.

  However, in order to obtain such a three-dimensional shaped object by metal stereolithography, a metal powder having characteristics different from those of metal powders used for other powder sintering such as compression molding and sintering is required. Become.

  For example, the particle diameter of the metal powder needs to be smaller than the thickness of the powder layer irradiated with the light beam. The finer the particle diameter, the higher the powder packing density and the better the light beam absorptance during modeling, so that the sintered density can be increased and the surface roughness of the modeled object can also be reduced. On the other hand, if the powder is too fine and agglomerates, the packing density of the powder decreases, and the powder layer cannot be spread thinly and uniformly.

  In addition, in order to increase the strength of the modeled object, the bonding area between the new sintered layer to be formed and the solidified sintered layer in the lower layer must be wide and the adhesion strength must be high. At the same time, it is necessary that the bonding area with the adjacent solidified sintered layer is wide and the adhesion strength is high.

  Furthermore, the upper surface of the new sintered layer should not rise too much. When the next powder layer is laid to form the next layer, if the bulging amount is equal to or greater than the thickness of the powder layer, the formation of the powder layer itself becomes difficult.

  Then, the metal powder irradiated with the light beam is partially melted or partially melted and then rapidly solidified to form a sintered layer. If the wettability at the time of melting is large, the adjacent sintered layer If the bonding area is large and the fluidity is large, the swell is small. Therefore, it is desired that the fluidity when melted is large and the wettability is also large.

  Moreover, as for the three-dimensional shape molded article manufactured by metal stereolithography, metal powder adheres to the surface of the molded article, and the surface roughness is deteriorated. In order to use this three-dimensional shaped object as a high-precision plastic injection mold, etc., metal powder adhering to the surface of the object must be removed, and workability when processing such as cutting finish is performed It is desirable that it is good.

  In addition, there should be no large cracks in the appearance of the modeled object, and it is desirable that the internal structure be free of microcracks in consideration of the flow of fluid (cooling water) inside the injection mold. .

  Next, the composition of the metal powder will be described. It is difficult to produce a high-density three-dimensional shaped object by irradiating a laser with only metal-based powder as a metal powder. This is because it is difficult to integrate the next sintered layer into the previously formed iron sintered layer without a gap. Even if chrome molybdenum steel powder is used as iron-based powder, chrome molybdenum steel itself has high hardness and excellent mechanical strength, but with chrome molybdenum steel powder alone, a sintered layer cannot be made without gaps, The three-dimensional shaped object obtained by laser irradiation has a low sintered density and a low strength.

  In the case where the iron-based powder is an alloy containing a large amount of nickel component, the strong oxide film formed on the surface of the powder inhibits fusion integration between the iron-based powders. The problem becomes exaggerated. 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 three-dimensional shaped objects by laser irradiation, the advantage is I can't show it at all. If the energy of laser irradiation is increased to eliminate the obstacle of the oxide film on the surface of the powder, iron-based powder containing chromium molybdenum steel and nickel components can be sufficiently fused and integrated. Becomes large and requires excessive electric power, which increases the manufacturing cost. Further, since the scanning speed of the laser cannot be increased, the production efficiency is also reduced, and a shaped article made with an excessive amount of irradiation energy is likely to be warped or deformed by thermal stress.

  Copper, when melted, has good fluidity, 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 a metal powder composed of iron-based powder and copper or copper alloy powder is irradiated with laser, this copper or copper alloy melts first, filling the gaps between the iron-based powders, and at the same time, this becomes a binder and melts. To be integrated. When the laser irradiation energy is high, the iron-based powder forming the metal powder and the copper or copper alloy powder are melted to form an alloy. Since the fluidity of the molten metal increases as the difference between the melting temperature and the melting point increases, the fluidity when irradiated with the same energy is better for pure copper and manganese copper alloys than for pure copper. .

  When nickel is not contained in the iron-based powder but is mixed with the copper or copper alloy powder as the nickel powder, the fusion integration of these powders becomes good. And the hardened layer which consists of an iron-type component, nickel, copper, or a copper alloy component has the high sintered density, As a result, it becomes a thing with high toughness and intensity | strength.

  Moreover, it is extremely effective to add graphite powder to the iron-based powder in order to reduce microcracks in the formed object. The influence of the graphite powder on the shaped object will be described with reference to FIGS. FIG. 4 shows the bending strength, bending elastic modulus, and stickiness of the metal stereolithography when graphite is added to 0.3 wt%. Bending strength, bending elastic modulus and stickiness both show better results as the amount of graphite powder added increases. In addition, the value of stickiness shows the value of the absorbed energy in the Charpy impact test when the addition amount of graphite powder is 0.3% by weight as 1. FIG. 5 thru | or FIG. 8 shows the photograph of the cross section of a molded article when graphite powder is each addition amount. The smaller the amount of graphite added, the more microcracks indicated by arrow A are generated. When graphite powder is blended with iron-based powder for metal stereolithography, the shrinkage phenomenon that occurs when the metal powder melts and solidifies by laser irradiation, and the expansion phenomenon that occurs when carbon dissolves in iron. It is considered that the internal stress is reduced and the generation of microcracks is reduced.

  From this point of view, as shown in Patent Document 1, the present applicant has disclosed an iron-based powder (chromium molybdenum steel), a nickel or nickel-based alloy powder, a copper or copper-based alloy powder, and a graphite powder. We proposed a metal powder for metal stereolithography. Chrome molybdenum steel has strength and toughness, copper and copper alloy powders have wettability and fluidity, nickel and nickel alloy powders have strength and workability, and graphite powder absorbs light beams. Adopted from the viewpoint of rate and microcrack reduction.

  And in metal stereolithography, unsintered metal powder that has not been irradiated with laser is recovered and reused. However, molten metal generated during modeling, and cutting of the surface of the model in the metal stereolithography apparatus Since the swarf generated by is contained in the metal powder, it is necessary to screen the metal powder through a mesh to remove the swarf and swarf.

However, when sieving, there is a problem that light metal powder, particularly graphite powder having a small specific gravity, is scattered and reduced. FIG. 9 shows the metal powder collected after metal stereolithography. Cutting chips indicated by arrows B are mixed in the metal powder.
JP 2004-277877 A

  The present invention has been made to solve the above-mentioned conventional problems, and even if sieving for reuse, a powder component having a small specific gravity is not scattered and the compounding component does not fluctuate. The object is to provide a metal powder.

  In order to achieve the above-mentioned object, the invention of claim 1 is characterized in that a sintered layer is formed by irradiating a powder layer made of metal powder with a light beam, and a three-dimensional shaped object is formed by laminating the sintered layer. Metal powder for metal stereolithography used for metal stereolithography to obtain, iron-based powder, nickel and nickel-based alloy powder or both, copper and copper-based alloy powder or both, Graphite powder and a composition (hereinafter referred to as composition powder), and the composition powder is alloyed by a mechanical alloying method.

The invention of claim 2 is used for metal stereolithography in which a powder layer made of metal powder is irradiated with a light beam to form a sintered layer and the sintered layer is laminated to obtain a three-dimensional shaped object. A metal powder for metal stereolithography, comprising an iron-based powder, nickel and / or nickel-based alloy powder, copper and / or copper-based alloy powder and / or graphite powder, and composition A powder obtained by alloying two or more kinds of powders of the composition powders by a mechanical alloying method and one or more kinds of powders of the composition powders. Ri formed by the one of the two or more kinds of powder to be alloyed by a mechanical alloying method include graphite powder.

A third aspect of the present invention, in the metal laser sintering metal powder according to claim 2, by irradiating a light beam to a powder layer made of a metal powder forming a sintered layer, the lamination of the sintered layer It is used for metal stereolithography that obtains a three-dimensional shaped object by repeating the process of cutting and removing either or both of the surface part and the unnecessary part of the formed object.

The invention of claim 4 is the metal powder for metal stereolithography according to claim 2 or claim 3 , wherein the composition powder is alloyed by mechanical alloying and alloyed by mechanical alloying. The average particle diameter of each of the unconverted metal powders is 10 to 40 μm.

The invention according to claim 5 is the metal powder for metal stereolithography according to claim 2 or claim 3 , wherein the average particle diameter of the metal powder alloyed by the mechanical alloying method of the composition powder is mechanical alloying. 50-80% by weight of metal powder alloyed by mechanical alloying method is larger than the average particle size of metal powder not alloyed by the method, and metal powder not alloyed by mechanical alloying method 20 to 50% by weight.

The invention according to claim 6 is the metal powder for metal stereolithography according to claim 2 or claim 3 , wherein the average particle diameter of the metal powder alloyed by the mechanical alloying method of the composition powder is mechanical alloying. The metal powder which is smaller than the average particle diameter of the metal powder not alloyed by the method, alloyed by the mechanical alloying method is 20 to 50% by weight, and the metal powder not alloyed by the mechanical alloying method is 50 to 80% by weight.

  According to the first aspect of the present invention, the metal powder for metal stereolithography used for metal stereolithography is all alloyed by mechanical alloying to form a powder in a state where all metals are stacked, and graphite having a small specific gravity. Since the powder is also integrated with other metals, the graphite powder does not scatter and the compounding components do not fluctuate even when sieving and reusing.

According to the second aspect of the present invention, since two or more kinds of powders for metal stereolithography used for metal stereolithography are alloyed by the mechanical alloying method, when sieving and reused However, the alloyed metal powder does not scatter and the blending components do not fluctuate. Further, since graphite powder is alloyed with other metal powders by mechanical alloying method, even when sieving and reused, graphite powder having a small specific gravity does not scatter and the blending components do not fluctuate.

According to invention of Claim 3 , the effect similar to the effect in metal stereolithography is acquired also in metal stereolithography composite processing.

According to the invention of claim 4 , since the average particle diameter of the metal powder is the same, the fluidity of the metal powder is improved, and even when the powder layer is laid with a thickness of 50 μm, it can be laid with a uniform density. A molded product with a stable filling density of metal powder and few sintering defects can be produced.

According to the invention of claim 5 , since two kinds of metal powders having different average particle diameters are mixed, a molded article having a high packing density and a high sintering density can be produced.

According to the invention of claim 6 , since two kinds of metal powders having different average particle diameters are mixed, a molded article having a high packing density and a high sintering density can be made.

(First embodiment)
A metal stereolithography combined process using the metal stereolithography metal powder according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 shows a configuration of a metal stereolithography combined processing machine 1 that performs metal stereolithography combined processing. The metal stereolithography composite processing machine 1 includes a powder layer forming means 2 for laying a metal powder in a layer having a predetermined thickness, a sintered layer forming means 3 for emitting a light beam L and irradiating the light beam L to an arbitrary position, The removal means 4 which scrapes the circumference | surroundings of a molded article is provided. The powder layer forming means 2 includes an elevating table 20 that moves up and down, a modeling base (not shown) that is arranged on the elevating table 20 and serves as a foundation of a modeled object, and a metal powder powder layer 22 on the modeling base. And a squeezing blade 23 for spreading. The sintered layer forming means 3 includes a light beam transmitter 30 that emits a light beam L, and a galvanometer mirror 31 that scans the light beam L onto the powder layer 22. The removing means 4 includes a milling head 40 that cuts the periphery of the modeled object, and an XY drive mechanism 41 that moves the milling head 40 to a cutting location.

  The operation of the metal stereolithography composite processing machine 1 will be described with reference to FIGS. FIG. 2 shows a flow of the operation of the metal stereolithography composite processing machine 1, and FIG. 3 shows the operation of the metal stereolithography composite processing machine 1. The operation of the metal stereolithography composite processing machine 1 includes a powder layer forming step (S1) for spreading metal powder, and a sintered layer forming step (S2) for forming the sintered layer 24 by irradiating the powder layer 22 with the light beam L. And a removal step (S3) for cutting the surface of the modeled object. In the powder layer forming step (S1), the elevating table 20 is first lowered by Δt1 in the arrow Z direction (S11). The metal powder is supplied to the modeling base 21 (S12), the squeezing blade 23 is moved in the direction of arrow A, the supplied metal powder is leveled on the modeling base 21, and the powder having the predetermined thickness arrow Δt1 The layer 22 is formed (S13). Next, the process proceeds to the sintered layer forming step (S2), where a light beam L is emitted from the light beam transmitter 30 (S21), and the light beam L is scanned to an arbitrary position on the powder layer 22 by the galvanometer mirror 31 ( S22) The metal powder is melted and sintered to form a sintered layer 24 integrated with the modeling base 21 (S23).

  The powder layer forming step (S1) and the sintered layer forming step (S2) are repeated until the thickness of the sintered layer 24 reaches a predetermined thickness obtained from the tool length of the milling head 40, and the sintered layer 24 is laminated. To do.

  And when the thickness of the laminated | stacked sintered layer 24 becomes predetermined thickness, it transfers to a removal step (S3) and drives the milling head 40 (S31). The milling head 40 is moved in the directions of arrows X and Y by the XY drive mechanism 41 to cut the surface of the shaped object on which the sintered layer 24 is laminated (S32). And if modeling of a three-dimensional shaped model is not completed, the process returns to the powder layer forming step (S1). In this way, the three-dimensional shaped object is manufactured by repeating S1 to S3 and laminating the sintered layer 24.

  The irradiation path of the light beam L in the sintered layer forming step (S2) and the cutting path in the removal step (S3) are created in advance from three-dimensional CAD data. At this time, a machining path is determined by applying contour line machining. And the thickness of the sintered layer 24 which transfers to a removal step (S3) is changed according to the shape of a molded article. When the shape of the modeled object is inclined, a smooth surface can be obtained by shifting to the removal step (S3) at a time when the shape is thinner than a predetermined thickness.

  Next, the metal powder for metal stereolithography according to this embodiment will be described. The graphite powder is scattered by the sieving to prevent the graphite powder from being reduced, and each powder is alloyed by a mechanical alloying method so that each metal is uniformly dispersed. As the metal powder, chromium molybdenum steel (SCM440) powder, nickel (Ni) powder, copper manganese alloy (CuMnNi) powder, and flaky graphite (C) powder each having an average particle diameter of 100 μm are used. The blending composition is (70 wt% SCM440-20 wt% Ni-9 wt% CuMnNi-0.3 wt% C).

  In these compounding compositions, all metal powders are mechanically alloyed by a ball mill, and the particle diameter of all metal powders is set to about 30 μm. The atmosphere in the ball mill container is an Ar gas atmosphere, the balls used for milling are steel balls having a diameter of 10 mm, and the operation time is 48 hours. The produced metal stereolithography metal powder is used in the metal stereolithography composite processing machine 1, and the unsintered metal powder is screened and reused.

  Each metal is alloyed into a stacked powder by mechanical alloying method, and graphite powder with low specific gravity is also integrated with other metals, so when reusing by sieving However, light metal powders, especially graphite powders are not scattered and the blending components do not fluctuate. Moreover, since the particle diameter and specific gravity of all the metal powders are almost the same, and the graphite powder is integrated with other powders, the fluidity of the powder is improved. Even when the powder layer 22 is laid on the thickness, the powder layer 22 can be laid at a uniform density, and the molded product has a stable filling density of metal powder and few sintering defects. In addition, graphite powder is mechanically bonded to other metal powders without using an organic adhesive or the like, so that the sintered density is increased and the amount of fumes generated by evaporation of the organic adhesive during laser irradiation is reduced. No contamination of the lens in the device.

(Second Embodiment)
The metal powder for metal stereolithography which concerns on the 2nd Embodiment of this invention is demonstrated. In the present embodiment, metal powder having the same composition as in the first embodiment is used, but the particle diameter of the metal powder and the type of metal powder alloyed by the mechanical alloying method are different. As the metal powder, chromium molybdenum steel powder having an average particle diameter of 100 μm, nickel powder having an average particle diameter of 30 μm, copper manganese alloy powder having an average particle diameter of 30 μm, and flaky graphite powder are used.

  Only 70% by weight of chromium molybdenum steel powder and 0.3% by weight of carbon powder are alloyed by a mechanical alloying method to obtain a metal powder having an average particle size of 30 μm. The metal powder subjected to mechanical alloying, the remaining 20% by weight of nickel powder and 9% by weight of copper-manganese alloy powder are mixed by a screw mixer to obtain a metal powder for metal stereolithography.

  Compared with the metal stereolithography metal powder according to the first embodiment, only a part of the metal powder is alloyed by the mechanical alloying method, so there is no effect of preventing fluctuations in the blending amount of the non-alloyed metal. The other effects are the same as those according to the first embodiment. In particular, since the particle diameter of the metal powder subjected to mechanical alloying and the particle diameter of the metal powder not subjected to mechanical alloying are the same, the fluidity of the powder is also good. Moreover, since the number of times of mechanical alloying is small, the cost can be reduced.

  In mechanical alloying of chromium molybdenum steel powder and carbon powder, some chromium molybdenum steel powder and carbon powder may be alloyed without alloying all the chromium molybdenum steel powder. The same effect as that obtained by alloying all chromium molybdenum steel powders can be obtained, and the number of mechanical alloying operations can be reduced, so that the cost can be reduced. However, in that case, the particle diameter of the remaining chromium molybdenum steel powder not subjected to mechanical alloying must be about 30 μm.

  Further, the graphite powder may be mechanically alloyed with nickel powder or copper alloy powder. It has the same effect as mechanical alloying with chromium molybdenum steel. However, powder having a particle diameter of 100 μm is used for the mechanical alloying powder, and powder having a particle diameter of 30 μm is used for the powder not mechanically alloying.

(Third embodiment)
A metal powder for metal stereolithography according to a third embodiment of the present invention will be described. In the present embodiment, metal powder having the same composition as in the first embodiment is used, but the particle diameter of the metal powder and the type of metal powder alloyed by the mechanical alloying method are different. Two or more kinds of chromium molybdenum steel powder, nickel powder, and copper manganese alloy powder are alloyed by a mechanical alloying method. The metal powder to be alloyed by the mechanical alloying method has an average particle diameter of 100 μm, and the metal powder not to be mechanically alloyed has an average particle diameter of 30 μm. The metal powder alloyed to 30 μm and the metal powder not mechanically alloyed are mixed by mechanical alloying to obtain a metal powder for metal stereolithography.

  Compared with the metal stereolithography metal powder according to the first embodiment, the graphite powder is not alloyed with other metal powders by the mechanical alloying method, so the reduction of the graphite powder during sieving cannot be prevented. The effect is the same as that according to the first embodiment, and the number of times of mechanical alloying is small, so the cost can be reduced.

(Fourth embodiment)
The metal powder for metal stereolithography which concerns on the 4th Embodiment of this invention is demonstrated. In the present embodiment, metal powder having the same composition as that in the first embodiment is used, but the particle diameter of the metal powder is different. A chromium molybdenum steel powder having an average particle diameter of 100 μm, a nickel powder having an average particle diameter of 10 μm, a copper manganese alloy powder having an average particle diameter of 10 μm, and a flaky graphite powder are used.

  Only 70% by weight of chromium molybdenum steel powder and 0.3% by weight of carbon powder are mechanically alloyed to obtain 30 μm alloy powder. The mechanically alloyed powder, 20% by weight of nickel powder and 9% by weight of copper manganese alloy powder are mixed to obtain a metal powder for metal stereolithography. About 70% by weight is a powder having an average particle diameter of 30 μm, and about 30% by weight is a metal powder having a mean particle diameter of 10 μm. By mixing two kinds of metal powders having different average particle diameters, the packing density of the metal powder is increased, and the sintered density of the shaped article is also increased.

  The average particle diameter of the two types of metal powders may be 25 to 35 μm on the larger side and 5 to 15 μm on the smaller side. Further, the proportion of the metal powder having the larger average particle diameter may be 50 to 80% by weight of the whole, and the proportion of the metal powder having the smaller average particle diameter may be 20 to 50% by weight of the whole.

  There is no relationship between the effect of increasing the packing density by mixing two types of metal powders having different average particle sizes and the type of metal of the metal powder. For example, a metal powder having a large average particle size is a chromium molybdenum steel powder. And nickel powder are alloyed by mechanical alloying, and the metal powder having a small average particle diameter may be chromium molybdenum steel powder and copper manganese alloy powder.

(Fifth embodiment)
A metal powder for metal stereolithography according to a fifth embodiment of the present invention will be described. In this embodiment, the metal powder alloyed by the mechanical alloying method in the fourth embodiment is used as a metal powder having a smaller average particle diameter.

  Chromium molybdenum steel powder, nickel powder, copper manganese alloy powder, and flaky graphite powder each having an average particle diameter of 30 μm are used. Only 30 wt% chromium molybdenum steel powder and 0.3 wt% carbon powder are mechanically alloyed to obtain a 10 μm alloy powder. The mechanical alloying conditions are that the atmosphere in the ball mill container is an Ar gas atmosphere, the ball used for milling is a steel ball having a diameter of 5 mm, and the operation time is 72 hours. It can be made fine by reducing the diameter of the ball used for milling and extending the operation time.

  The mechanically alloyed powder, 40 wt% chromium molybdenum steel powder, 20 wt% nickel powder, and 9 wt% copper manganese alloy powder are mixed to obtain a mixed powder for metal stereolithography. About 70% by weight is a powder having an average particle diameter of 30 μm, and about 30% by weight is a mixed powder composed of a powder having an average particle diameter of 10 μm. By mixing two kinds of metal powders having different average particle diameters, the packing density of the metal powder is increased, and the sintered density of the shaped article is also increased.

  As in the fourth embodiment, the average particle size may be 25 to 35 μm on the larger side and 5 to 15 μm on the smaller side. Further, the proportion of the metal powder having the larger average particle diameter may be 50 to 80% by weight of the whole, and the proportion of the metal powder having the smaller average particle diameter may be 20 to 50% by weight of the whole. In addition, as for the type of the metal having the larger average particle diameter and the smaller one, any metal may be used as in the fourth embodiment.

  In the first to fifth embodiments, the composition of the metal powder was (70 wt% SCM440-20 wt% Ni-9 wt% CuMnNi-0.3 wt% C). The effect of the mechanical alloying method according to the embodiment is effective regardless of the composition of the metal powder (70 wt% SCM440-20 wt% Ni-9 wt% CuMnNi-0.3 wt% C).

  In particular, the blending amount of iron-based powder is 60 to 90% by weight, the blending amount of both nickel and nickel-based alloy is 5 to 35% by weight, and / or both of copper and copper-based alloy. By blending 0.2 to 0.8% by weight of graphite powder into metal powder with a powder content of 5 to 15% by weight, it is possible to make a shaped product with high strength and no microcracks inside. Furthermore, the iron-based powder is a chromium molybdenum steel powder, or a tool steel that has a martensite structure due to rapid cooling and has a high hardness and a hardness that decreases by tempering, such as carbon tool steel, die steel, high-speed tool steel, etc. By using a powder, it is possible to obtain a molded article that has high strength and high hardness and good surface machinability.

  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, in this embodiment, although it used for the metal stereolithography composite processing machine 1, even if it uses for the metal stereolithography which cuts the surface of a modeling thing after manufacturing the whole three-dimensional shape modeling thing by metal stereolithography. Good. Moreover, the conditions of the mechanical alloying method should just be the conditions which a metal powder is alloyed and a predetermined particle diameter is obtained irrespective of the conditions of various embodiment.

The block diagram of the metal optical modeling composite processing machine which performs the metal optical modeling composite processing which concerns on embodiment of this invention. The flowchart of operation | movement of a metal stereolithography composite processing machine. The figure which shows operation | movement of a metal stereolithography composite processing machine. The figure which shows the relationship between the amount of graphite powder addition in the conventional metal stereolithography, and a bending test result. The photograph of the cross-sectional structure of the conventional metal stereolithography object which does not add graphite powder. The photograph of the cross-sectional structure | tissue of the conventional metal stereolithography thing which added graphite powder 0.1weight%. The photograph of the cross-sectional structure of the conventional metal stereolithography object which added 0.2 weight% of graphite powder. The photograph of the cross-sectional structure | tissue of the conventional metal stereolithography thing which added 0.3 weight% of graphite powder. The SEM photograph of the conventional metal powder collect | recovered from the metal stereolithography composite processing machine.

Explanation of symbols

22 Powder layer 24 Sintered layer

Claims (6)

A metal powder for metal stereolithography used in metal stereolithography used to form a sintered layer by irradiating a light beam onto a powder layer made of metal powder, and obtaining a three-dimensional shaped article by laminating the sintered layer. There,
From powder (hereinafter referred to as composition powder) comprising iron-based powder, nickel and / or nickel-based alloy powder, copper and / or copper-based alloy powder, and graphite powder Consisting of
A metal powder for metal stereolithography, wherein the composition powder is alloyed by a mechanical alloying method. A metal powder for metal stereolithography used in metal stereolithography used to form a sintered layer by irradiating a light beam onto a powder layer made of metal powder, and obtaining a three-dimensional shaped article by laminating the sintered layer. There,
From powder (hereinafter referred to as composition powder) comprising iron-based powder, nickel and / or nickel-based alloy powder, copper and / or copper-based alloy powder, and graphite powder Consisting of
A powder alloying two or more kinds of powder of said composition powder by a mechanical alloying method, and one or more powders of said composition powder, Ri formed by mixing,
A metal powder for metal stereolithography , wherein graphite powder is contained in one of two or more kinds of powders alloyed by the mechanical alloying method . A step of forming a sintered layer by irradiating a powder layer made of metal powder with a light beam, and cutting and / or removing one or both of a surface portion and an unnecessary portion of a shaped article formed by stacking the sintered layers. The metal powder for metal stereolithography according to claim 2 , wherein the metal powder for metal stereolithography is used for metal stereolithography to obtain a three-dimensional modeled article by repeating the steps. The average particle size of each of the metal powder alloyed by the mechanical alloying method and the metal powder not alloyed by the mechanical alloying method is 10 to 40 µm. Metal powder for metal stereolithography of Claim 2 or Claim 3 . The average particle size of the metal powder alloyed by the mechanical alloying method of the composition powder is larger than the average particle size of the metal powder not alloyed by the mechanical alloying method,
Metal powders alloyed by a mechanical alloying method is 50 to 80 wt%, claim 2 or claim in which the metal powder which is not alloyed, characterized in that 20 to 50% by weight by mechanical alloying Item 4. The metal powder for metal stereolithography according to Item 3 . The average particle size of the metal powder alloyed by the mechanical alloying method of the composition powder is smaller than the average particle size of the metal powder not alloyed by the mechanical alloying method,
Metal powders alloyed by a mechanical alloying method is 20 to 50 wt%, claim 2 or claim in which the metal powder which is not alloyed, characterized in that 50 to 80% by weight by mechanical alloying Item 4. The metal powder for metal stereolithography according to Item 3 .