KR20180003141A - Metal powder 3d printer using plasma treatment - Google Patents

Abstract

The present invention relates to a metal powder three dimensional printing apparatus using plasma treatment. The metal powder three dimensional printing apparatus uses metal powder as a raw material, forms a three dimensional shape by irradiating the metal powder with a laser, and includes a plasma treating device for plasma treating the metal powder prior to irradiation through the laser. Thus, the metal powder used as the raw material can be plasma-treated with the plasma treating device before laser irradiation to clean, reduce, or spheronize the raw metal powder. As a result, the present invention is able to prevent the cost and the time according to a post-process after completion of a product in advance, and consequently to improve the quality of the product to be produced.

Description

Technical Field [0001] The present invention relates to a metal powder 3D printing apparatus using plasma processing,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a 3D printing apparatus using a metal powder as a raw material, and more particularly, to a 3D printing apparatus for plasma processing a metal powder as a raw material.

3D printing is a printing technique that can produce a specific product in three dimensions. It refers to a method or device that can produce an actual product in a three-dimensional space, such as printing on paper using a three-dimensional design.

In the early stage of development, it was confined to plastic materials, but now it is spreading to the nylon and metal materials that make products with the tendency to spread to the general public with the popularized products of millions of won and the reduced volume.

Among 3D printing technologies, SLA (Stereolithography) and SLS (Selective Laser Sintering) technologies are made by melting powdered material using laser, and the laser used is a condensed linear beam.

On the other hand, the term "cladding" refers to a welding technique commonly referred to as welding two or more sides of a steel to which other metals are bonded, and generally refers to a welding technique for repairing corroded or broken workpieces. In addition, cladding is a technique of bonding two base metals by laser welding, which makes it easy to bond two base metals, but it is difficult to restore only the damaged or corroded parts.

Particularly, laser-aided direct metal manufacturing is a technique in which a laser is precisely aligned according to three-dimensional digital data of 3D objects stored in a computer using a functional material (metal, alloy or ceramic) There is an advantage in that it is possible to produce tools in the form of a three-dimensional product or a product in a very short time by using a laser cladding technique which directly fuses the glass. Here, the three-dimensional shape information includes three-dimensional CAD data, medical CT (Computer Tomography) and MRI (Magnetic Resonance Imaging) data, digital data measured with a 3D object digitizing system . In addition, a tool refers to a mass production mold required for producing a product such as a die or a mold.

These technologies can be used to produce metal prototypes, mass production molds, complex final products and tools in a short period of time comparable to conventional machining methods such as cutting and casting using CNC (Computerized Numerical Control) And can be applied to the restoration, remodeling and repairing of molds by using reverse engineering.

However, when the metal powder is 3D-printed using the laser direct metal forming technology, the metal powder to be supplied may be oxidized because the laminating process is performed mainly at atmospheric pressure, resulting in defects in the manufactured product.

Korean Patent Laid-Open No. 10-2016-0003521 (published on Jan. 11, 2016) Korean Registered Patent 1606629 (Registered on March 23, 2016)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a 3D printing apparatus for forming a three-dimensional shape by using metal powder, And to improve the quality of a manufactured product.

It is another object of the present invention to provide a 3D printing apparatus for forming a three-dimensional shape using metal powder, in which a metal powder used as a raw material is subjected to a plasma treatment so that the metal powder can be cleaned.

It is still another object of the present invention to provide a 3D printing apparatus for forming a three-dimensional shape using metal powder, in which a metal powder used as a raw material is subjected to a plasma treatment to reduce the metal powder.

In order to achieve the above object, the present invention provides a metal powder 3D printing apparatus for forming a three-dimensional shape by using a metal powder as a raw material and irradiating the metal powder with a laser, wherein the metal powder The plasma processing apparatus may include a plasma processor for plasma processing the plasma.

Preferably, the metal powder 3D printing apparatus includes a bed on which the three-dimensional product is formed, a laser head for supplying the metal powder onto the bed and irradiating the laser, And a shield gas supply unit for supplying a shield gas to the laser head, wherein the plasma processor is installed on a path through which the metal powder is supplied to the bed.

Preferably, the metal powder 3D printing apparatus includes a powder bed in which the metal powder is laminated, an applicator for laminating the metal powder to the powder bed, a powder supply unit for supplying the metal powder to the applicator, And a scanner unit for selectively irradiating the laser beam supplied from the laser generating unit onto the powder bed, wherein the plasma processor is installed on the path through which the metal powder is supplied to the powder bed .

Preferably, the plasma processor can use argon and oxygen as the plasma gas. Further, helium and argon-hydrogen may be used as the plasma gas.

Preferably, a plurality of the plasma processors are provided. In addition, the plasma processor may include a first plasma processor including argon and oxygen as a plasma gas, and a second plasma processor including helium and argon-hydrogen as a plasma gas.

Preferably, the plasma processor can use a glow discharge region.

Preferably, the plasma processor includes a plasma head for generating a plasma, and a plasma gas supply unit for supplying a plasma gas to the plasma head, wherein the plasma head has a nozzle shape. For example, the plasma head may include a pair of electrodes, the first electrode may be arranged in a bar shape at the central portion, and the second electrode may be arranged in a cylindrical shape surrounding the first electrode, The first electrode may be formed to be longer than the second electrode and protrude to the outside of the second electrode to be exposed toward the metal powder.

Preferably, the plasma processor includes a plasma head for generating a plasma, and a plasma gas supply unit for supplying a plasma gas to the plasma head, wherein the plasma head has a slit shape. For example, the plasma head may include a pair of electrodes, wherein the first electrode is formed in the form of a flat plate having a length in the paper surface direction, and the second electrode is formed in a flat plate shape having a length in the paper- And a discharge space may be formed between the first electrode and the second electrode.

In the 3D printing apparatus according to the present invention, the metal powder used as a raw material is subjected to a plasma treatment with a plasma processor before laser irradiation, thereby bringing about the effect of cleaning, reducing or spheroidizing the raw metal powder.

Thus, the 3D printing apparatus of the present invention can prevent the cost and time of the post-process after completion of the product by preventing the metal powder used as the raw material from being plasma-treated and then melted / fused by the laser, It is possible to improve the quality of the product manufactured by the method.

FIG. 1 is a schematic view showing a metal powder 3D printing apparatus 100 using a plasma process according to a first embodiment of the present invention,
FIG. 2 is a schematic view of a metal powder 3D printing apparatus 200 using a plasma process according to a second embodiment of the present invention,
FIG. 3 is a schematic view showing a plasma head 300 of a plasma processor applied to a 3D printing apparatus according to the present invention.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or preliminary meaning and the inventor shall properly define the concept of the term in order to describe its invention in the best possible way It should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention. It should be noted that the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention, It should be understood that various equivalents and modifications are possible.

Hereinafter, a metal powder 3D printing apparatus using a plasma process according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic view of a metal powder 3D printing apparatus 100 using a plasma process according to a first embodiment of the present invention.

As shown in FIG. 1, the 3D printing apparatus 100 according to the first embodiment of the present invention includes a bed 110 on which a product is formed, A shielding gas supply unit 140 for supplying a shield gas to the laser head 120, a gas supply unit 130 for supplying the shielding gas to the bed (not shown) And a plasma processor 150 for plasma-processing the metal powder supplied to the plasma generator 110. The plasma processor 150 includes a plasma head 152 for generating a plasma and a plasma gas supply unit 154 for supplying a plasma gas to the plasma head 152. Herein, the metal powder is exemplified as the 3D printing material, but the metal powder is not limited thereto, and the metal alloy is naturally included in the metal powder, and other functional materials such as ceramics may also be included.

In the 3D printing process of the metal powder according to the first embodiment, the metal powder M is supplied in real time in the laser head 120, and the laser L is irradiated to the metal powder M to be supplied. At this time, the laser L is irradiated to the central portion, the metal powder M is supplied onto the optical path of the laser from the outside, and the shield gas G is supplied to the outside of the metal powder M to be supplied.

As described above, the 3D printing apparatus according to the first embodiment is capable of supplying metal powder in a protective gas atmosphere in real time, and simultaneously melting and coagulating the metal powder using a high-output laser to stack the product W to be. At this time, when the laminating process is performed at the atmospheric pressure rather than the vacuum chamber, the metal powder supplied through the powder supplying unit 130 may be oxidized, thereby preventing the metal powder from being supplied through the plasma processor 150. At this time, it is preferable that the plasma processor 150 is an atmospheric pressure plasma method in which plasma is generated under atmospheric pressure (atmospheric pressure).

On the other hand, the discharge shape of the plasma varies depending on the type of the current and the voltage. Specifically, there are a corona discharge region, a glow discharge region, a streamer discharge region, and an arc discharge region. Among them, the plasma processor according to the first embodiment preferably generates no arc and generates a stable glow plasma at a low temperature, which is intended to stably plasma-process a fine metal powder.

In addition, since the effect of the plasma treatment depends on the kind of the plasma gas, argon gas (Ar) and oxygen (O2) can be mixed and used as the plasma gas. Here, when argon and oxygen are used as a plasma gas, the surface cleaning effect of the metal powder can be obtained by the plasma treatment. That is, the organic matter and moisture on the surface of the metal powder can be removed through the plasma treatment, and the effect of removing the static electricity is also obtained.

In addition, the plasma processor 150 according to the first embodiment of the present invention may use a mixture of helium gas (He) and argon-hydrogen gas (Ar-H) as a plasma gas. Here, when a mixture of helium gas and argon-hydrogen is used as the plasma gas, the metal powder can be reduced by the plasma treatment. That is, if the metal powder is reduced before laser melting, oxidation of the metal powder in the laser melting process can be suppressed.

In this way, for the cleaning effect or the reducing effect of the plasma treatment through the plasma processor 150, the temperature of the plasma is preferably about 300 degrees, and the treatment time is preferably in the range of 1 to 2 seconds.

Further, the plasma treatment brings about the effect of sphering the particles of the metal powder. This is because the surface of the metal powder is momentarily melted and coagulated due to the instantaneous supply of energy to the metal powder. When the metal powder particles are spherical, the pore generation inside the formed product can be reduced.

In the first embodiment shown in FIG. 1, one plasma processor 150 is provided in the laser head 120, but a plurality of plasma processors 150 may be disposed. At this time, some of the plurality of plasma processors 150 may use argon and oxygen as a plasma gas for the cleaning effect, and the rest may use helium and argon-hydrogen as a plasma gas for the reducing effect.

1, the plasma processor 150 may be disposed in the laser head 120, but it is also possible to arrange the plasma processor 150 in the shield gas supply unit 140 or the shield gas supply unit 140 and the laser head 120 It may be placed on the connecting powder feed pipe. As described above, the plasma processor 150 can realize the above-described predetermined effect when the metal powder is disposed so as to be plasma-processed before being melted by a laser.

FIG. 2 is a schematic view of a metal powder 3D printing apparatus 200 using a plasma process according to a second embodiment of the present invention.

As shown in FIG. 2, the 3D printing apparatus 200 according to the second embodiment includes a powder bed 210 in which metal powder for forming a product is stacked, a coating layer 210 for depositing metal powder on the powder bed 210, A laser generator 240 for generating and supplying a laser beam; a laser generator 240 for generating a laser beam from the laser generator 240; And a plasma processor 260 for plasma-processing the powder supplied to the powder bed 210. The plasma processor 260 may be a plasma processing apparatus, The plasma processor 260 includes a plasma head 262 for generating a plasma and a plasma gas supply unit 264 for supplying a plasma gas to the plasma head 262. Herein, the metal powder is exemplified as the 3D printing material, but the metal powder is not limited thereto, and the metal alloy is naturally included in the metal powder, and other functional materials such as ceramics may also be included.

A metal powder layer is laid on a powder bed 210 having a predetermined area in the powder supplying part 230 and the laser is selectively irradiated according to the design drawing. It melts and stacks up. That is, the powder supplying unit 230 stores the metal powder and supplies the metal powder to the applicator 220, and the applicator 220 uniformly applies the metal powder onto the powder bed 210 Laminated. Next, a process in which the scanner 250 is laser-irradiated with the metal powder deposited on the powder bed 210 to melt and coagulate the metal powder, and then the new metal powder is laminated by the applicator 220 And the production of the product W is carried out.

At this time, as described in the first embodiment, argon and oxygen are mixed with the plasma gas, and the cleaning effect can be obtained through the plasma treatment. In addition, a reducing effect can be obtained by mixing helium and argon-hydrogen and performing plasma treatment.

2, the plasma head 262 of the plasma processor 260 is illustrated as being disposed on the metal powder transfer path between the powder supply unit 230 and the applicator 220, The processor 260 may be disposed within the applicator 220 or within the powder supply 230.

Since the type, temperature, and time of the plasma generated in the plasma processor 260 are the same as those of the plasma processor 150 of the first embodiment described above, the duplicated description will be omitted.

3 is a schematic view illustrating a plasma head 300 applied to a 3D printing apparatus according to the first and second embodiments of the present invention.

Referring to FIG. 3, the plasma head 300 includes a pair of electrodes 310a and 310b. The first electrode 310a is disposed in a rod shape at a central portion, and the second electrode 310b is disposed in a rod- The discharge space P1 is formed between the first electrode 310a and the second electrode 310b so as to surround the first electrode 310b.

At this time, the first electrode 310a is formed longer than the second electrode 310b, and is protruded to the outside of the second electrode 310b to be exposed toward the metal powder.

The plasma gas flows through the inlet 320 in the upper portion of the drawing and passes through the discharge space P1 between the first electrode 310a and the second electrode 310b and is discharged outside. The plasma generated in the discharge space P1 between the first electrode 310a and the second electrode 310b is applied to the lower ends of the first electrode 310a and the second electrode 310b and the metal powder M And the plasma P2 can be directly irradiated to the metal powder M to be supplied.

As described above, in the 3D printing apparatus 100 according to the first embodiment, the metal powder M is supplied in real time from the laser head. Therefore, in order to effectively supply the plasma on the supply path of the metal powder M, the plasma processor, which is applied to the 3D printing apparatus 100 according to the first embodiment, The head 300 may be applied. The plasma head 300 has a nozzle shape and can effectively provide a plasma in a narrow area and is easy to mount on a laser head.

If the first electrode 310a is formed in the shape of a flat plate having a length in the paper surface direction and the second electrode 310b is formed in the shape of a flat plate having a length in the direction of the paper surface (symmetrically) And this shape can be adapted to be disposed in the roller portion of the 3D printing apparatus 200 according to the second embodiment or in the lower plane of the roller portion.

It is to be understood that the above-described embodiments are to be considered in all respects as illustrative and not restrictive, and the scope of the present invention will be indicated by the appended claims rather than by the foregoing detailed description. It is intended that all changes and modifications that come within the meaning and range of equivalency of the claims, as well as any equivalents thereof, be within the scope of the present invention.

100, 200: 3D printing device
110: Bed
120: laser head
130, 230: Powder supply part
140: shield gas supply part
150, 260: Plasma processor
152, 262, 300: Plasma head
154, 264: Plasma gas supply part
210: Powder bed
220: applicator
240: laser generator
250: Scanner part
310a: first electrode
310b: second electrode
L: Laser
M: metal powder
G: Shield gas
P1: Plasma region
P2: transition plasma region

Claims (12)

A metal powder 3D printing apparatus using a metal powder as a raw material and forming a three-dimensional shape by irradiating the metal powder with a laser,
And a plasma processor for plasma-processing the metal powder before irradiation with the laser.
The method according to claim 1,
In the metal powder 3D printing apparatus,
A bed on which the three-dimensional product is formed,
A laser head for supplying the metal powder onto the bed and irradiating the laser,
A powder supply unit for supplying the metal powder to the laser head,
And a shield gas supply unit for supplying a shield gas to the laser head,
Wherein the plasma processor is installed on a path through which the metal powder is supplied to the bed.
The method according to claim 1,
In the metal powder 3D printing apparatus,
A powder bed in which the metal powder is laminated,
An applicator for laminating the metal powder on the powder bed,
A powder supply unit for supplying the metal powder to the applicator,
A laser generator for generating and supplying the laser;
And a scanner unit for selectively irradiating the laser beam supplied from the laser generator onto the powder bed,
Wherein the plasma processor is installed on a path through which the metal powder is supplied to the powder bed.
The method according to claim 2 or 3,
Wherein the plasma processor uses argon and oxygen as a plasma gas.
The method according to claim 2 or 3,
Wherein the plasma processor uses helium and argon-hydrogen as a plasma gas.
The method according to claim 2 or 3,
Wherein a plurality of the plasma processors are provided.
The method according to claim 6,
The plasma processor
A first plasma processor including argon and oxygen as a plasma gas,
And a second plasma processor including helium and argon-hydrogen as the plasma gas.
The method according to claim 1,
Wherein the plasma processor uses a glow discharge region.
3. The method of claim 2,
Wherein the plasma processor includes a plasma head for generating a plasma and a plasma gas supply unit for supplying a plasma gas to the plasma head,
Wherein the plasma head has a nozzle shape.
10. The method of claim 9,
Wherein the plasma head comprises:
A plasma display panel comprising a pair of electrodes, wherein the first electrode is arranged in a rod-like shape at the central portion, and the second electrode is arranged in a cylindrical shape surrounding the first electrode, Forming a space,
Wherein the first electrode is formed to be longer than the second electrode so as to be protruded to the outside of the second electrode and exposed to the metal powder side.
The method of claim 3,
Wherein the plasma processor includes a plasma head for generating a plasma and a plasma gas supply unit for supplying a plasma gas to the plasma head,
Wherein the plasma head has a slit shape.
12. The method of claim 11,
Wherein the plasma head comprises:
Wherein the first electrode is formed in a flat plate shape having a length in the paper surface direction and the second electrode is formed in a flat plate shape having a length in the direction of the paper surface symmetrically with respect to the first electrode, And a discharge space is formed between the first electrode and the second electrode.

Images