JP6959296B2 - Electron beam type surface-treated metal powder for 3D printers and its manufacturing method - Google Patents

Description

The present invention relates to an electron beam type surface-treated metal powder for a 3D printer and a method for producing the same.

A method of obtaining a metal molded product by so-called sintering, in which an aggregate of powdered metal materials is heated to melt and solidify, is a kind of powder metallurgy and is widely used in the manufacture of various mechanical parts. Such powder metallurgy has attracted particular attention with the development of so-called 3D printers. The 3D printer is also called additive manufacturing (AM), and a laminating method using EB or a laser is well known as a method for manufacturing a three-dimensional metal shaped object. This involves forming a metal powder layer on a sintering table, irradiating a predetermined portion of the powder layer with a beam to sinter, and then forming a new powder layer on the powder layer. By irradiating the predetermined portion with a beam and sintering the predetermined portion, a sintered portion integrated with the sintered portion of the lower layer is formed. By repeating this, a three-dimensional shape is formed layer by layer from the powder, and it is possible to form a complicated shape that is difficult or impossible by the conventional processing method. By these methods, it is possible to directly mold a desired three-dimensional three-dimensional model into a metal material from shape data such as CAD (Non-Patent Document 1).

In the three-dimensional model produced by sintering the powdered metal material in this way, it is used as a part to be incorporated into a machine or the like directly or after secondary processing by surface grinding or polishing. Things are going on. In the field of 3D printers, compared to resin products that have been put into practical use in advance, it is technically difficult to manufacture metal parts, but they have high strength and can withstand use at high temperatures. There are features that cannot be obtained with resin.

"Special Feature 2-3D Printer | Fascinated! Hen | "Design / Manufacturing Solutions Exhibition" Report "Diversification of modeling materials such as resin, paper, and metal" [Nikkei BP "Nikkei Manufacturing August Issue" (Issue Date: August 1, 2013) Nos. 64 to 68 page〕

Comparing the EB used for molding metal parts with the laser beam, the former is characterized in that more precise molding is possible. Therefore, when trying to manufacture a part with high dimensional accuracy with a 3D printer, it is appropriate to use EB.

In molding by EB, the metal powder is required to be conductive in a deposited state so that the beam is accurately irradiated to a predetermined position. Therefore, when a metal powder having no conductivity in the deposited state is used as a raw material, it is necessary to temporarily sinter the deposited metal powder to ensure conductivity before irradiating the electron beam. Further, even if the metal powder has no problem in conductivity, preheating is required for the purpose of removing thermal strain of the molded product in order to maintain the molded shape after completion. In general, preheating is cooler than tentative sintering, but even with preheating, metal powder is partially sintered, so a curved hollow pipe structure, such as a hollow spiral shape or hollow When molding a part with a complicated shape that has a hollow part, such as a part whose part is closed with a terminal, it is impossible to remove the partially sintered metal powder that remains inside even by blast shot processing after the part is molded. Yes, it could not be manufactured in the past. If there is a metal powder that does not need to be tentatively sintered, does not need to be partially sintered by preheating, and can be sintered by directly irradiating the accumulated metal powder with EB, such a problem can be solved. By avoiding this, a metal molded product having a complicated shape such as having a hollow portion can be easily molded with high dimensional accuracy.

Therefore, in view of these points, an object of the present invention is that there is no need for tentative sintering, partial sintering by preheating, and EB is directly irradiated to the state of the deposited metal powder for baking. The purpose is to provide a metal powder that can be tied.

As a result of diligent research, the present inventor applies surface treatment to the metal powder, which will be described later, to have conductivity in the deposited state, so that there is no need for temporary sintering, and partial sintering can be performed by preheating. We have arrived at the present invention by finding that a metal powder suitable for sintering by EB irradiation can be obtained by having conductivity in a deposited state.

Therefore, the present invention is as follows (1) or less.
(1)
The particle size D50 (median diameter) of the metal powder is 10 μm or more,
XPS multiplex measurement of surface-treated metal powder detected N photoelectrons at 100 cps (count per second) or higher.
A surface-treated metal powder for an EB sintered 3D printer that does not sinter when the ^{surface-treated metal powder is heated at 600 ° C. for 10 minutes in an atmosphere of a vacuum degree of 10 -1 Pa to 10 -3 Pa.}
(2)
The metal powder is a Ti alloy metal powder containing 0 to 10% by mass of Al, 0 to 5% by mass of V, and 0 to 1% by mass of Fe, and the balance is Ti and unavoidable impurities.
The particle size D50 (median diameter) of the metal powder is 10 μm or more,
XPS multiplex measurement of surface-treated metal powder detected N photoelectrons at 100 cps (count per second) or higher.
The surface-treated metal for an EB sintered 3D printer according to (1), wherein sintering does not occur when the ^{surface-treated metal powder is heated at 600 ° C. for 10 minutes in an atmosphere of a vacuum degree of 10 -1 Pa to 10 -3 Pa.} powder.
(3)
The metal powder contains 45 to 65% by mass of Ni, 15 to 30% by mass of Cr, 0 to 10% by mass of Mo, 0 to 6% by mass of Nb, 0 to 5% by mass of Fe, and 0 to 2% by mass of Ti. %, Al is 0 to 1% by mass, and one or more selected from the group of Co, Mn, Cu, and Si is contained in a total of 0 to 2% by mass, and the balance is a metal powder of Ni alloy composed of unavoidable impurities. can be,
The particle size D50 (median diameter) of the metal powder is 10 μm or more,
XPS multiplex measurement of surface-treated metal powder detected N photoelectrons at 100 cps (count per second) or higher.
The surface-treated metal for an EB sintered 3D printer according to (1), wherein sintering does not occur when the ^{surface-treated metal powder is heated at 600 ° C. for 10 minutes in an atmosphere of a vacuum degree of 10 -1 Pa to 10 -3 Pa.} powder.
(4)
The metal powder contains 15 to 20% by mass of Cr, 2 to 15% by mass of Ni, 0 to 5% by mass of Mo, 0 to 5% by mass of Cu, 0 to 2% by mass of Mn, and 0 to 1% by mass of Si. Austenite-based, ferrite-based, martensite-based, and containing 0 to 1% by mass in total of one or more selected from the group of%, Co, C, P, and S, and the balance consisting of Fe and unavoidable impurities. It is a metal powder of stainless steel belonging to any of the precipitation hardening systems.
The particle size D50 (median diameter) of the metal powder is 10 μm or more,
XPS multiplex measurement of surface-treated metal powder detected N photoelectrons at 100 cps (count per second) or higher.
The surface-treated metal for an EB sintered 3D printer according to (1), wherein sintering does not occur when the ^{surface-treated metal powder is heated at 600 ° C. for 10 minutes in an atmosphere of a vacuum degree of 10 -1 Pa to 10 -3 Pa.} powder.
(5)
An EB-sintered 3D printer modeled product obtained by EB-sintering the surface-treated metal powder for an EB-sintered 3D printer according to any one of (1) to (4).

(11)
A step of EB-irradiating the surface-treated metal powder for an EB-sintered 3D printer according to any one of (1) to (4) to EB-sintering.
EB sintered type 3D printer modeled product manufacturing method including.
(12)
A step of preheating the surface-treated metal powder for an EB sintered 3D printer according to any one of (1) to (4).
A process of EB irradiation and EB sintering of a preheated surface-treated metal powder for an EB sintering type 3D printer.
EB sintered type 3D printer modeled product manufacturing method including.
(13)
The process of EB sintering is
The method according to any one of (11) to (12), which is a step of EB-irradiating the surface-treated metal powder for an EB-sintered 3D printer in a vacuum to EB-sinter.
(14)
The preheating process is
The method according to any one of (12) to (13), which is a step of preheating the surface-treated metal powder for an EB sintered 3D printer in a vacuum.
(15)
The method according to any one of (13) to (14), wherein the vacuum is a vacuum having a degree of vacuum of 10 ^{-1 Pa to 10 -3 Pa.}

Since the surface-treated metal powder for an EB sintered 3D printer according to the present invention is conductive in a deposited state, it is possible to stably irradiate an electron beam, there is no need for tentative sintering, and preheating is used. Since sintering does not proceed, EB makes it possible to manufacture parts (molded products) having a complicated shape such as having a hollow portion, which was impossible in the past, by EB sintering of a 3D printer.

[Surface-treated metal powder for EB sintered 3D printer]
The surface-treated metal powder for an EB sintered 3D printer of the present invention is a surface-treated metal powder suitable as a metal powder raw material in an EB sintered 3D printer.
The particle size D50 (median diameter) of the metal powder is 10 μm or more,
XPS multiplex measurement of surface-treated metal powder detected N photoelectrons at 100 cps (count per second) or higher.
The surface-treated metal powder has a characteristic that sintering does not occur when the metal powder is heated at 600 ° C. for 10 minutes in an atmosphere ^{of a vacuum degree of 10 -1 Pa to 10 -3 Pa.}

[Ti alloy powder]
In a preferred embodiment, the surface-treated metal powder contains 0 to 10% by mass of Al, 0 to 5% by mass of V, and 0 to 1% by mass of Fe, and the balance is Ti and impurities inevitably mixed. It can be a metal powder of Ti and a Ti alloy.
A feature of 3D printers is that they can manufacture products that are difficult to model by cutting, forging, punching, etc., which are general metal material processing methods, and can be applied to all metal powders that are difficult to process. Is.
Ti is relatively easy to process in what is called pure titanium such as JIS type 1 and type 2, but it has poor workability among metal materials including alloys.
Al is an additive element used as an element for strengthening the α phase in Ti alloys, but if the amount added is large, the hot workability may be lowered, and the upper limit is set to 10% by mass.
V is used as an additive element for stabilizing the β phase in a Ti alloy, but since the effect does not change even if it is added at a certain concentration or more, the upper limit is set to 5% by mass.
Fe is an inexpensive metal and may be positively added as long as it does not adversely affect the alloy properties, but it may adversely affect the corrosion resistance of the alloy, and the upper limit is set to 1.0% by mass.

[Ni alloy metal powder]
In a preferred embodiment, the surface-treated metal powder contains 45 to 65% by mass of Ni, 15 to 30% by mass of Cr, 0 to 20% by mass of Fe, 0 to 10% by mass of Mo, and 0 to 0 to Nb. It contains 6% by mass, 0 to 2% by mass of Ti, 0 to 1% by mass of Al, and 0 to 2% by mass in total of one or more selected from the group of Co, Mn, Cu, and Si, and the balance is unavoidable. It can be a Ni alloy metal powder composed of impurities that are mixed in.
Ni is used as a main component of an alloy that is required to have high corrosion resistance and strength at a high temperature, and is 45% by mass or more and 65% by mass or less from the composition amount at which these required properties can be obtained.
Cr and Mo are used as components of an alloy that requires high corrosion resistance and may be added positively, but the upper limit is set to 30% by mass or less and 5% by mass or less, respectively, from the effect of improving the characteristics.
Fe is an inexpensive metal and may be added within a range that does not impair the properties and manufacturability, but the upper limit is set to 20% by mass so as not to reduce the corrosion resistance.
Nb, Ti, and Al were added for the purpose of increasing the strength by strengthening precipitation, and were set to 6% by mass or less, 2% by mass or less, and 1% by mass or less, respectively, up to a concentration at which a sufficient effect could be obtained.

[Stainless steel metal powder]
In a preferred embodiment, the surface-treated metal powder contains Cr in an amount of 15 to 20% by mass, Ni in an amount of 2 to 15% by mass, Mo in an amount of 0 to 5% by mass, Cu in an amount of 0 to 5% by mass, and Mn in an amount of 0 to 0. Austenite containing 2% by mass, 0 to 1% by mass of Si, 0 to 1% by mass in total of one or more selected from the group of Co, C, P, and S, and the balance consisting of Fe and unavoidable impurities. It can be a metal powder of stainless steel belonging to any of a system, a ferrite system, a martensite system, and a precipitation hardening system.

[Maraging steel]
In a preferred embodiment, the surface-treated metal powder contains 17 to 26% by mass of Ni, 7 to 13% by mass of Co, 3.0 to 5.5% by mass of Mo, and 0.15 to 2. 0% by mass, Al 0.05 to 0.30% by mass, Si 0.12% by mass or less, Mn 0.12% by mass or less, C 0.03% by mass or less, the balance Fe and unavoidable impurities It can be a metal powder of maraging steel made of.

[Surface-treated metal powder]
As the metal powder to be surface-treated, a metal powder produced by a known method can be used. If the size is several μm or more, it is industrially common to use a metal powder produced by a dry method represented by an atomizing method, which is excellent in manufacturing cost, but a wet method such as a reduction method is used. It is also possible to use the metal powder produced by.

[Metal powder particle size D50 (median diameter)]
The particle size D50 (median diameter) of the surface-treated metal powder can be, for example, 10 μm or more and 20 μm or more, and can be, for example, 300 μm or less and 250 μm or less. In a preferred embodiment, the particle size D50 (median diameter) can be, for example, 10 μm to 300 μm, 15 to 250 μm, 20 to 200 μm, 50 μm to 100 μm.

[Surface treatment of metal powder]
In the surface treatment method, the metal powder is mixed with a surface treatment reagent containing an element selected from the group consisting of Al, Si, Ti, Zr, Ce, and Sn, then separated, and the metal powder is treated with the surface treatment reagent. Can be obtained by performing the step of obtaining. In a preferred embodiment, the surface treatment reagent can be an alkaline solution. In a preferred embodiment, if the solution of the surface treatment reagent is not alkaline, the metal powder can be mixed with the solution of the surface treatment reagent after active treatment with the alkaline solution.
In a preferred embodiment, a step of removing a part of the adhering component from the metal powder treated with the surface treatment reagent with an aqueous solvent can be further performed, and the washed metal powder is dried to perform surface treatment. The step of obtaining the obtained metal powder can be performed.
When the metal powder is mixed with the solution of the surface treatment reagent, it is important to include the surface treatment reagent in a specific weight range described later with respect to the metal powder per unit weight, as described later. If the surface treatment reagent is less than the lower limit of a specific weight range, the surface treatment effect of the metal powder is insufficient. In addition, if the surface treatment reagent exceeds a specific weight, the effect of the surface treatment does not change, and it is industrially disadvantageous such as an increase in the solution cost of the reagent. Therefore, it may be below the upper limit of the specific weight range. preferable.

[Alkaline treatment]
In a preferred embodiment, the metal powder can be treated with an alkali prior to the surface treatment reagent treatment if the solution of the surface treatment reagent is not alkaline. Examples of the alkaline aqueous solution include an aqueous solution such as sodium hydroxide. The alkaline treatment is carried out by mixing the metal powder by a known method, stirring if desired, and separating the metal powder, and may be washed with pure water if desired.

[Surface treatment reagent]
The surface treatment reagent contains an element selected from the group consisting of Al, Si, Ti, Zr, Ce, and Sn, preferably Al, Si, or Ti. As a suitable surface treatment reagent, for example, a coupling agent having the above-mentioned metal element can be mentioned. For example, silane, titanate or aluminate can be mentioned. Examples of those solutions exhibiting alkalinity include coupling agents having an amino group. As a solution showing neutrality or acidity, for example, a coupling agent having an epoxy group can be mentioned. For example, a coupling agent having no amino group can be mentioned. Examples of the non-amino group-containing coupling agent include epoxysilane, vinylsilane, methacrylsilane, and mercaptosilane.

[Coupling agent having an amino group]
As the coupling agent having an amino group, for example, one or more coupling agents selected from the group consisting of aminosilane, ureidosilane, amino-containing titanate, and amino-containing aluminate can be used. As the coupling agent having an amino group, for example, one having a structure having an amino group at the end of the molecular chain coordinated to the central atom Al, Ti, or Si can be used.

[Aminosilane]
In a preferred embodiment, the coupling agent having an amino group includes the following formula I:
H ₂ N-R ^1- Si (OR ² ) ₂ (R ³ ) (Formula I)
(However, in the above formula I,
R1 is a hydrocarbon of C1 to C12 having a linear or branched, saturated or unsaturated, substituted or unsubstituted, cyclic or acyclic, heterocyclic or heterocyclic. It is a divalent group and
R2 is an alkyl group of C1 to C5.
R3 is an alkyl group of C1 to C5 or an alkoxy group of C1 to C5. )
Aminosilane represented by can be used.

In a preferred embodiment, R1 of the above formula I comprises a linear or branched, saturated or unsaturated, substituted or unsubstituted, cyclic or acyclic, heterocyclic or heterocyclic ring. It is a divalent group of C1-C12 hydrocarbons that does not have, and more preferably R1 is a substituted or unsubstituted divalent group of C1-C12 linear saturated hydrocarbons, substituted or unsubstituted. Branched Saturated Hydrocarbons C1-C12 Divalent Group, Substituted or Unsubstituted, C1-C12 Linear Unsaturated Hydrocarbon Divalent Group, Substituted or Unsubstituted, Branched C1-C12 Divalent groups of unsaturated hydrocarbons, substituted or unsubstituted, divalent groups of cyclic hydrocarbons of C1 to C12, substituted or unsubstituted, divalent groups of heterocyclic hydrocarbons of C1 to C12, substituted or substituted. It can be a group selected from the group consisting of unsubstituted divalent groups of C1 to C12 aromatic hydrocarbons. In a preferred embodiment, R1 of the above formula I is a divalent group of saturated or unsaturated chain hydrocarbons of C1 to C12, more preferably atoms at both ends of the chain structure are free valences. It is a divalent group having. In a preferred embodiment, the number of carbon atoms of the divalent group can be, for example, C1 to C12, preferably C1 to C8, preferably C1 to C6, and preferably C1 to C3.

In a preferred embodiment, R1 of the above formula I is − (CH ₂ ) _n −, − (CH ₂ ) _n − (CH) _m − (CH ₂ ) _j-1 −, − (CH ₂ ) _n − ( CC) − (CH ₂ ) _n-1 −, − (CH ₂ ) _n −NH − (CH ₂ ) _m −, − (CH ₂ ) _n −NH − (CH ₂ ) _m −NH − (CH ₂ ) _j −, − (CH ₂ ) _n-1 − (CH) NH ₂ − (CH ₂ ) _m-1 −, − (CH ₂ ) _n-1 − (CH) NH ₂ − (CH ₂ ) _m-1 −NH A group selected from the group consisting of − (CH ₂ ) _j −, −CO−NH− (CH ₂ ) _n −, −CO−NH− (CH ₂ ) _n −NH− (CH _{2 ) m−} (CH 2). However, n, m, and j are integers of 1 or more). (However, (CC) above represents a triple bond of C and C.) In a preferred embodiment, R1 is − (CH ₂ ) _n − or − (CH ₂ ) _n −NH − (CH ₂ ). It can be _{m −.} (However, the above (CC) represents a triple bond of C and C.) In a preferred embodiment, the hydrogen of the above divalent group R1 may be substituted with an amino group, for example, 1 to 1. Three hydrogens, such as 1-2 hydrogens, such as one hydrogen, may be substituted with amino groups.

In a preferred embodiment, n, m, and j of the above formula I may be independently set to an integer of 1 or more and 12 or less, preferably an integer of 1 or more and 6 or less, and more preferably an integer of 1 or more and 4 or less. It can be, for example, an integer selected from 1, 2, 3, 4, and can be, for example, 1, 2, or 3.

In a preferred embodiment, R2 of the above formula I can be an alkyl group of C1 to C5, preferably an alkyl group of C1 to C3, more preferably an alkyl group of C1 to C2, for example, a methyl group or ethyl. It can be a group, an isopropyl group, or a propyl group, preferably a methyl group or an ethyl group.

In a preferred embodiment, R3 of the above formula I can be an alkyl group of C1 to C5, preferably an alkyl group of C1 to C3, more preferably an alkyl group of C1 to C2, for example. It can be a methyl group, an ethyl group, an isopropyl group, or a propyl group, preferably a methyl group or an ethyl group. Further, R3 of the above formula I can be an alkoxy group of C1 to C5, preferably an alkoxy group of C1 to C3, more preferably an alkoxy group of C1 to C2, and for example, a methoxy group or an ethoxy group. It can be a group, an isopropoxy group, or a propoxy group, preferably a methoxy group or an ethoxy group.

[Amino-containing titanate]
In a preferred embodiment, as a coupling agent having an amino group, the following formula II:
(H ₂ N-R ^1- O) _p Ti (OR ² ) _q (Equation II)
(However, in the above formula II,
R1 is a hydrocarbon of C1 to C12 having a linear or branched, saturated or unsaturated, substituted or unsubstituted, cyclic or acyclic, heterocyclic or heterocyclic. It is a divalent group and
R2 is an alkyl group of C1 to C5 having a linear or branched structure.
p and q are integers of 1 to 3 and p + q = 4. )
Amino group-containing titanates represented by can be used.

In a preferred embodiment, as R1 of the above formula II, the group listed as R1 of the above formula I can be preferably used. As R1 of the above formula II, for example, − (CH ₂ ) _n −, − (CH ₂ ) _n − (CH) _m − (CH ₂ ) _j-1 −, − (CH ₂ ) _n − (CC) − ( CH ₂ ) _n-1 −, − (CH ₂ ) _n −NH − (CH ₂ ) _m −, − (CH ₂ ) _n −NH − (CH ₂ ) _m −NH − (CH ₂ ) _j −, − ( _{CH 2) n-1 - (} CH) NH 2 - (CH 2) m-1 -, - (CH 2) n-1 - (CH) NH 2 - (CH 2) m-1 -NH- (CH 2 ) A group selected from the group consisting of _j −, −CO−NH− (CH ₂ ) _n −, −CO−NH− (CH ₂ ) _n −NH− (CH ₂ ) _{m− (where n, m,} j is an integer of 1 or more). As a particularly suitable R1, − (CH ₂ ) _n −NH − (CH ₂ ) _m − (where n + m = 4, particularly preferably n = m = 2) can be mentioned.

As R2 of the above formula II, the group listed as R2 of the above formula I can be preferably used. In a preferred embodiment, an alkyl group of C3 can be mentioned, and particularly preferably a propyl group and an isopropyl group.

P and q in the above formula II are integers of 1 to 3, p + q = 4, and preferably a combination of p = q = 2 and a combination of p = 3 and q = 1. As an amino group-containing titanate in which a functional group is arranged in this way, Plain Act KR44 (manufactured by Ajinomoto Fine-Techno Co., Ltd.) can be mentioned.

[Coupling agent with epoxy group]
As the coupling agent having an epoxy group, for example, one having a structure having an epoxy group at the end of the molecular chain coordinating with the central atom Al, Ti, or Si can be used.

In a preferred embodiment, as a coupling agent having an epoxy group, the following formula III:
H ₂ COCH-R ^4- Si (OR ² ) ₂ (R ³ ) (Equation III)
(However, in the above formula I,
R4 is a linear or branched, saturated or unsaturated, substituted or unsubstituted, cyclic or acyclic, heterocyclic or heterocyclic hydrocarbon of C1 to C12. It is a divalent group and
R2 is an alkyl group of C1 to C5.
R3 is an alkyl group of C1 to C5 or an alkoxy group of C1 to C5. )
Epoxysilane represented by can be used.

The above group H ₂ COCH- represents an epoxy group.

In a preferred embodiment, as R4 of formula III, for example, − (CH ₂ ) _n −, − (CH ₂ ) _n − (CH) _m − (CH ₂ ) _j-1 −, − (CH ₂ ) _n. − (CC) − (CH ₂ ) _n-1 −, − (CH ₂ ) _n −O − (CH ₂ ) _m −, − (CH ₂ ) _n −O− (CH ₂ ) _m −O− (CH ₂₎ ) _{Can be a group selected from the group consisting of j} − (where n, m, j are integers greater than or equal to 1). As a particularly suitable R4, − (CH ₂ ) _n −O − (CH ₂ ) _m − (where n + m = 4, particularly preferably n = 1, m = 3) can be mentioned.

In a preferred embodiment, R2, R3 of formula III can be selected from the groups described above as R2, R3 of formula I.

[Non-amino-containing titanate]
In a preferred embodiment, as a coupling agent having no amino group, the following formula IV:
(R ^5- O) _p Ti (OR ² ) _q (Equation IV)
(However, in the above formula IV,
R5 is a saturated or unsaturated, substituted or unsubstituted, acyl group of C2-C20 fatty acids having a linear or branched structure.
R2 is an alkyl group of C1 to C5 having a linear or branched structure.
p and q are integers of 1 to 3 and p + q = 4. )
Amino group-containing titanates represented by can be used.

In a preferred embodiment, R2 of formula IV can be selected from the groups described above as R2 of formula I.

In a preferred embodiment, R5 can be an acyl group of fatty acids of C2 to C20, preferably C10 to C20, preferably C16 to C18. For example, crotonic acid, acrylic acid, methacrylic acid, capric acid, pelargonic acid, capric acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, palmitreic acid, margaric acid, stearic acid, oleic acid, vacene acid, linoleic acid, (9,12,15) -linolenic acid, (6,9,12) -linolenic acid, dihomo-γ-linolenic acid, eleostearic acid, tubercrostearic acid, arachidic acid (eicosanoic acid), 8,11- Of fatty acids selected from the group consisting of eikosadienoic acid, 5,8,11-eikosatrienoic acid, arachidonic acid, behenic acid, lignoseric acid, nervonic acid, elaidic acid, erucic acid, docosahexaenoic acid, eikosapentaenoic acid, stearidonic acid It can be an acyl group.

P and q in the above formula IV are integers of 1 to 3, p + q = 4, and preferably a combination of p = q = 2 and a combination of p = 3 and q = 1. As a non-amino group-containing titanate in which a functional group is arranged in this way, Plain Act KR44TTS (manufactured by Ajinomoto Fine-Techno Co., Ltd.) can be mentioned.

[Mixing of surface treatment reagent with solution]
When the metal powder is mixed with the solution of the surface treatment reagent, for example, 0.005 to 0.500 g, 0.010 to 0.100 g, 0.025 to 0 of the surface treatment reagent is added to 1 g of the metal powder. It can include an amount in the range of .050 g. It can be mixed and stirred by a known method. For example, it can be carried out at room temperature, for example, at a temperature in the range of 5 to 80 ° C. and 10 to 40 ° C.

[Elements adsorbed by surface treatment]
The surface-treated metal powder is preferably an element in which one or more elements selected from the group consisting of Al, Si, Ti, Zr, Ce, and Sn are adsorbed on the surface of the metal powder by the surface treatment. It can be one element selected from the group consisting of Al, Si, and Ti, more preferably Si or Ti.

[Adhesion of N]
In a preferred embodiment, the metal powder can be surface-treated with a coupling agent having an amino group, and in this case, the surface-treated metal powder has nitrogen derived from the amino group of the coupling agent on its surface. include.

[Multiplex measurement of XPS]
When the surface of the surface-treated metal powder for an EB sintered 3D printer obtained by performing the above surface treatment on the metal powder is measured by the multiplex measurement of XPS, the photoelectrons of N are, for example, 100 cps (count per second). As described above, it is detected at 110 cps or more, and is detected at, for example, 300 cps or less and 250 cps or less. The multiplex measurement of XPS can be performed under the conditions described later in the examples.

[Conductivity]
The surface-treated metal powder for EB sintered type 3D printer obtained by performing the above surface treatment on the metal powder is excellent even when the powder is laminated as it is and is not temporarily sintered. It has conductivity (conductivity before EB sintering). Due to this conductivity, the laminate of surface-treated metal powder can be suitably sintered by EB. In the present application, having conductivity means that it is determined to have good conductivity in the conductivity test of the metal powder described later in the examples.

[Preheat resistance]
The surface-treated metal powder for EB sintered type 3D printer obtained by performing the above surface treatment on the metal powder does not cause partial sintering when it is laminated and preheated, that is, it is excellent. Has preheating resistance. This preheating, the degree of vacuum, for example 10 ^-3 Pa or more, 10 ^-2 Pa or higher, in the following atmosphere 10 ^-1 Pa, the temperature, for example 400 ℃ ~700 ℃, 450 ℃ ~680 ℃, 500 ℃ ~ It can be carried out in the range of 650 ° C. for a period of time, for example, 1 minute to 20 minutes, 3 minutes to 15 minutes. In the present application, having preheating resistance means that it is determined to be unsintered in the heat sintering test described later in the examples.

[Manufacturing of 3D printer models]
After laminating the surface-treated metal powder for EB sintered 3D printer, preheating is performed if desired, and then sintered by EB (electron beam) irradiation, and the hollow portion or the closed portion has a hollow portion. It is possible to mold metal molded products having complicated shapes such as mixed ones with high dimensional accuracy. Therefore, the method of manufacturing the EB-sintered 3D printer model using the surface-treated metal powder for the EB-sintered 3D printer, and the manufactured EB-sintered 3D printer model are also within the scope of the present invention. Is.

Hereinafter, the present invention will be described in detail with reference to Examples. The present invention is not limited to the following specific modes of implementation.

[Metal powder]
As the metal powder, copper powder, Inconel 718, Inconel 625, Ti—Al alloy, and SUS316L produced by the atomization method, each having a particle size D50 (median diameter) of 60 to 90 μm was used. The analysis results of the main compositions of these metal powders are shown in Table 1 below.

[Adjustment of aqueous coupling agent solution]
500 mL of each of the following coupling agent aqueous solutions using various coupling agents was prepared.
Silane:
Diaminosilane A-1120 (manufactured by MOMENTIVE)
Epoxy Silane Z-6040 (manufactured by Toray Dow Corning)
Titanate:
Amino group-containing Plain Act KR44 (manufactured by Ajinomoto Fine Techno Co., Ltd.)
Amino group-free Plain Act KR44TTS (manufactured by Ajinomoto Fine Techno Co., Ltd.)
The concentration was adjusted at 5 vol%. The pH was adjusted to 4 with dilute sulfuric acid except for the amino coupling agent.

[surface treatment]
The surface treatment procedure for metal powder is as follows.
(1) Ultrasonic waves (manufactured by Tech Jam Co., Ltd., model number W-113, output 100 W, frequency 100 kHz) are applied to metal powder in dilute sulfuric acid (10%) to which 0.1 to 0.5% hydrochloric acid is added. After stirring for 60 seconds and allowing to stand to discard the supernatant, pure water is added.
(2) Repeat discarding the supernatant and adding pure water until the pH of the supernatant reaches 4 or higher.
(3) To 100 g of the metal powder weight, add 200 mL of a coupling agent aqueous solution containing a coupling agent having a weight ratio of each of those shown in Table 2.
(4) While stirring the liquid, apply ultrasonic waves (manufactured by Tech Jam Co., Ltd., model number W-113, output 100 W, frequency 100 kHz) to mix for 60 minutes.
(5) After suction-filtering the aqueous coupling agent solution with an aspirator, add pure water to the metal powder and further filter. Filtration is performed by adding 1.4 times pure water of dry metal powder and filtering the obtained liquid, and when ICP analysis is performed, the elements of Al, Si, Ti, Zr, Ce, and Sn derived from the coupling agent are used. Was carried out until the concentration became 50 ppm or less.
(6) The residue (metal powder) obtained by filtration was dried at 70 ° C. for 1 hour in a nitrogen atmosphere to obtain a surface-treated metal powder.

[XPS multiplex measurement]
N adhering to the surface of the surface-treated metal powder was analyzed under the following conditions.
Surface N: A cylindrical container having a diameter of 0.5 mm was filled with 0.5 g of metal powder and spread so that the bottom surface was covered without gaps. XPS multiplex measurement of the upper surface of the metal powder spread in a cylindrical container. (Semi-quantitative analysis of N adhering to the surface of the upper half of the metal powder)
Equipment: ULVAC-PHI 5600MC
Ultimate vacuum: 5.7 x 10 ^-9 Torr
Excitation source: Monochromatic Al Kα
Output: 210W
Detection area: 800 μmφ
Incident angle, extraction angle: 45 °
Target elements: Three types of elements, C, N, and O

[Heat sintering test]
The procedure for the heat sintering test of surface-treated metal powder is as follows.
(1) Sieve the metal powder through a sieve with a wire diameter of 88 μm and an opening of 125 μm.
(2) A cylindrical container having a diameter of 100 mm and a height of 50 mm is filled with the metal powder that has passed through the sieve in (1) until the height reaches 20 mm.
(3) Place the container filled with metal powder in the firing furnace and set the degree of vacuum to 10 ^{-1 Pa to 10 -3} Pa.
(4) The temperature inside the furnace is raised from room temperature to 600 ° C. in 30 minutes, and when the temperature reaches 600 ° C., the temperature is maintained for 10 minutes, and then the firing furnace is turned off to cool the furnace.
(5) Take out the container when the temperature inside the furnace drops below 100 ° C.
(6) Take out the metal powder from the container, measure the weight (= M total), and measure the weight (= M on) of the metal powder remaining on the sieve through a sieve having a wire diameter of 88 μm and a mesh opening of 125 μm.
(7) Weight ratio: From M on / M total, when the weight ratio was 0.01 or less, it was judged to be unsintered.

[Conductivity of metal powder]
The conductivity when the surface-treated metal powder was deposited was confirmed by the following procedure by SEM (scanning electron microscope).
(1) Attach conductive double-sided tape on the sample observation stage.
(2) A copper pipe having a height of 5 mm, a diameter of 10 mm, and a thickness of 0.1 mm is attached and fixed on the double-sided tape of (1).
(3) Put metal powder in a copper pipe up to the height of the pipe and deposit it.
(4) The SEM observation condition is 20 kV, and the metal powder near the center of the pipe is observed at a magnification of 500 times. At this time, if the metal powder is charged up and moves, the conductivity is poor (NG) (x in the table), and if the metal powder does not move and can be observed without problems, the conductivity is good (OK) (table). In, it was judged as ○).

[result]
The results of the above tests are summarized in Table 2 below.

According to the present invention, the EB sintering type has conductivity in a deposited state, can stably irradiate an electron beam, does not require temporary sintering, and does not proceed with sintering by preheating. A surface-treated metal powder for a 3D printer can be obtained. The present invention is an industrially useful invention.

Claims (10)

The particle size D50 (median diameter) of the metal powder is 10 μm or more,
A surface-treated metal powder in which the metal powder is surface-treated with a coupling agent having an amino group.
What
By multiplex measurement of XPS for surface-treated metal powder, N photoelectrons were detected at 100 cps (count per second) or more and 230 cps or less.
Surface-treated Conductive surface for EB-sintered 3D printer, which is determined to be unsintered in a heat-sintering test in which metal powder is heated at 600 ° C. for 10 minutes in an atmosphere with a vacuum degree of 10 ^{-1 Pa to 10 -3 Pa.} Treated metal powder. The metal powder contains 0 to 10% by mass of Al, 0 to 5% by mass of V, and 0 to 1% by mass of Fe, and the balance is a Ti alloy composed of Ti and unavoidable impurities (including the case where it is pure Ti). ) Metal powder,
The particle size D50 (median diameter) of the metal powder is 10 μm or more,
By multiplex measurement of XPS for surface-treated metal powder, N photoelectrons were detected at 100 cps (count per second) or more and 230 cps or less.
The EB sintering mold according to claim 1, wherein the surface-treated metal powder is determined to be unsintered in a heat sintering test in which the surface-treated metal powder is heated at 600 ° C. for 10 minutes in an atmosphere ^{of a vacuum degree of 10 -1 Pa to 10 -3 Pa.} Conductive surface-treated metal powder for 3D printers. The metal powder contains 45 to 65% by mass of Ni, 15 to 30% by mass of Cr, 0 to 10% by mass of Mo, 0 to 6% by mass of Nb, 0 to 20 % by mass of Fe, and 0 to 2% by mass of Ti. %, Al is 0 to 1% by mass, and one or more selected from the group of Co, Mn, Cu, and Si is contained in a total of 0 to 2% by mass, and the balance is a metal powder of Ni alloy composed of unavoidable impurities. can be,
The particle size D50 (median diameter) of the metal powder is 10 μm or more,
By multiplex measurement of XPS for surface-treated metal powder, N photoelectrons were detected at 100 cps (count per second) or more and 230 cps or less.
The EB sintering mold according to claim 1, wherein the surface-treated metal powder is determined to be unsintered in a heat sintering test in which the surface-treated metal powder is heated at 600 ° C. for 10 minutes in an atmosphere ^{of a vacuum degree of 10 -1 Pa to 10 -3 Pa.} Conductive surface-treated metal powder for 3D printers. The metal powder contains 15 to 20% by mass of Cr, 2 to 15% by mass of Ni, 0 to 5% by mass of Mo, 0 to 5% by mass of Cu, 0 to 2% by mass of Mn, and 0 to 1% by mass of Si. Austenite-based, ferrite-based, martensite-based, and containing 0 to 1% by mass in total of one or more selected from the group of%, Co, C, P, and S, and the balance consisting of Fe and unavoidable impurities. It is a metal powder of stainless steel belonging to any of the precipitation hardening systems.
The particle size D50 (median diameter) of the metal powder is 10 μm or more,
By multiplex measurement of XPS for surface-treated metal powder, N photoelectrons were detected at 100 cps (count per second) or more and 230 cps or less.
The EB sintering mold according to claim 1, wherein the surface-treated metal powder is determined to be unsintered in a heat sintering test in which the surface-treated metal powder is heated at 600 ° C. for 10 minutes in an atmosphere of a ^{vacuum degree of 10 -1 Pa to 10 -3 Pa.} Conductive surface-treated metal powder for 3D printers. An EB-sintered 3D printer modeled product obtained by EB-sintering the conductive surface-treated metal powder for an EB-sintered 3D printer according to any one of claims 1 to 4. A step of EB-irradiating the conductive surface-treated metal powder for an EB-sintered 3D printer according to any one of claims 1 to 4 to EB-sintering.
EB sintered type 3D printer modeled product manufacturing method including. A step of preheating the conductive surface-treated metal powder for an EB sintered 3D printer according to any one of claims 1 to 4.
A process of EB-irradiating and EB-sintering a preheated conductive surface-treated metal powder for an EB-sintered 3D printer.
EB sintered type 3D printer modeled product manufacturing method including. The process of EB sintering is
The method according to any one of claims 6 to 7, which is a step of EB-sintering the conductive surface-treated metal powder for an EB-sintered 3D printer by EB irradiation in a vacuum. The preheating process is
The method according to any one of claims 7 to 8, which is a step of preheating the conductive surface-treated metal powder for an EB sintered 3D printer in a vacuum. The method according to any one of claims 8 to 9, wherein the vacuum is a vacuum having a degree of vacuum of 10 ^{-1 Pa to 10 -3 Pa.}