KR20190011357A - Method of high resolution 3D printing using micro metal wire - Google Patents

Abstract

According to the present invention, a high resolution 3D printing method using a micro metal wire comprises the following steps of: a) providing a base material; b) irradiating pulsed laser to the micro metal wire on the base material to manufacture a metal layer formed as the micro metal wire is melted; and c) manufacturing a micro-laminated structure having an amorphous phase by cooling the metal layer.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a high-resolution 3D printing method using a micro-

The present invention relates to a high-resolution 3D printing method using a micro-metal wire to produce an amorphous 3D microstructure using a laser as a heat source.

3D printing is a technique commonly referred to as laminate manufacturing or AM (additive manufacturing), which refers to a manufacturing technique for three-dimensionally stacking features using a high-density heat source. It has the same technique and principle as the welding or overlay welding in existing welding, but it is a field attracting attention due to recent popularity of 3D printing technology.

3D printing (laminating manufacturing) using laser has attracted attention as an advantage of being able to produce very precise parts in a single process at the development stage of the rapid prototyping technology. However, since the production cost is high, the production time is long, The market has not been greatly expanded.

Laser lamination manufacturing technology can be roughly classified into three types. The first is laser sintering (LS), and the second and third are laser melting (LM) and laser metal deposition (LMD), respectively.

This laser lamination manufacturing technology is classified according to the mechanism of interaction between the metal powder and the laser, and it is classified into LS and LM / LMD according to whether the metal powder is partially melted or completely melted. In the classification method according to the metal powder supplying method, / LM is supplied in the form of a plate-like metal powder on the sintered bed whereas in LMD, the powder is supplied coaxially with the laser.

However, since such a laser lamination manufacturing technique is basically a method of using metal powder, it has problems in productivity, material efficiency, risk of oxidative contamination, and particularly difficult to control the shape, size, and the like in realizing high resolution 3D printing on a micro scale .

On the other hand, the amorphous metal material has a much higher tensile strength than the crystalline metal material due to the nature of the atomic structure, and has excellent properties such as toughness and corrosion resistance.

If the final fabricated structure (or laminate) has the above-mentioned amorphous characteristics in the 3D printing method, the disadvantages of the mechanical and chemical properties of the existing crystalline microstructures may be compensated.

Korean Patent No. 10-1682087

SUMMARY OF THE INVENTION The present invention provides a high-resolution 3D printing method using a micro-metal wire for manufacturing an amorphous 3D microstructure using a laser as a heat source.

Another object of the present invention is to provide a high-resolution 3D printing method using a micrometal wire having an excellent mechanical strength and an amorphous phase by adjusting the average diameter of the micrometal wire and the power of the pulsed laser.

It is another object of the present invention to solve the problems of the conventional powder feeding method, to produce a large amount of amorphous 3D microstructures, to control the shape of the 3D microstructures, to reduce the size of the 3D microstructures to micro- Resolution 3D printing method capable of controlling a high-resolution 3D printing method.

On the other hand, other unspecified purposes of the present invention will be further considered within the scope of the following detailed description and easily deduced from the effects thereof.

According to an aspect of the present invention, there is provided a high-resolution 3D printing method using a micro-metal wire, comprising: a) providing a substrate; b) irradiating a pulsed laser onto the substrate with a microwave metal wire to produce a metal layer formed by melting the microwave metal wire; And c) cooling the metal layer to produce an amorphous microstructured structure.

In the high-resolution 3D printing method using a micro-metal wire according to an embodiment of the present invention, the micro-metal wire may have an average diameter of 60 to 150 mu m.

In the high resolution 3D printing method using a micro-metal wire according to an embodiment of the present invention, the power of the pulse laser may be 40 W or less and 90 W or less.

In the high resolution 3D printing method using the microwave metal wire according to an embodiment of the present invention, the average diameter of the microwave metal wire and the power of the pulse laser are determined by a high-resolution 3D printing method using a micrometal wire satisfying the following relational expression :

[Relation 1]

E = a x D + b

Wherein E is the power (W) of the pulse laser irradiated on the unit area (탆 ² ) of the micro-metal wire, D is the average diameter (탆) of the micro-metal wire, ^{× 10 -4 ≤ a ≤ -1.1 ×} 10 -4, wherein b is ^{1.7 × 10 -3 ≤ b ≤ 4.7} × 10 - a ^2).

In the high-resolution 3D printing method using a micro-metal wire according to an embodiment of the present invention, the unit process may be repeatedly performed using the steps a) and b) as one unit process.

In the high-resolution 3D printing method using a micro-metal wire according to an embodiment of the present invention, in the step b)

The contact angle of the metal layer with respect to the surface of the substrate may be 20 to 100 degrees.

In the high-resolution 3D printing method using a micro-metal wire according to an embodiment of the present invention, the Vickers hardness of the micro-stacked structure may be 770 to 850 kg / mm ² .

The present invention also includes an amorphous microstructured structure manufactured by the above-described high-resolution 3D printing method.

The high-resolution 3D printing method using the micro-metal wire according to the present invention can produce an amorphous micro-layered structure by irradiating a pulsed laser on a micro-metal wire.

The high resolution 3D printing method using the microwave metal wire according to the present invention can produce an amorphous 3D microstructure having a smooth surface shape by controlling the average diameter of the microwave metal wire and the power of the pulsed laser, An amorphous 3D microstructure having a size in units or nano units can be produced.

The high-resolution 3D printing method using the micro-metal wire according to the present invention does not require a sintering process or a pressurizing process as compared with the conventional method of producing a three-dimensional material using powder, so that the process is simplified, The metal wires can be melted, so that various 3D microstructures can be manufactured without limitation of the shape.

The high-resolution 3D printing method using the micro-metal wire according to the present invention can produce an amorphous micro-layered structure having excellent mechanical properties.

On the other hand, even if the effects are not explicitly mentioned here, the effect described in the following specification, which is expected by the technical features of the present invention, and its potential effects are treated as described in the specification of the present invention.

1 is a flowchart of a high-resolution 3D printing method using a micro-metal wire according to an embodiment of the present invention.
2 is a cross-sectional SEM photograph of the micro-metal wire used in Example 2 and Comparative Example 2 of the present invention.
3 is a SEM photograph of the microstructured structure manufactured according to the second embodiment of the present invention.
4 is an SEM photograph of the microstructured structure manufactured according to Comparative Example 2 of the present invention.
5 is a cross-sectional BSE photograph and an XRD graph of the microstructured structure manufactured according to the second embodiment of the present invention.
6 is a cross-sectional BSE photograph and XRD graph of a microstructured structure manufactured according to Comparative Example 2 of the present invention.
7 is a graph showing a correlation between E (power of pulse laser irradiated per unit area) applied to the microwave metal wire used in Examples and Comparative Examples of the present invention and D (diameter) of the microwave metal wire.

Hereinafter, the present invention will be described in detail. The following embodiments and drawings are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. In addition, unless otherwise defined in the technical and scientific terms used herein, unless otherwise defined, the meaning of what is commonly understood by one of ordinary skill in the art to which this invention belongs is as follows, A description of known functions and configurations that may unnecessarily obscure the gist of the present invention will be omitted.

In describing the present invention, the term "microstructured structure" means a laminated structure of a micro order. For example, the average height of the microstructured structures may be 500 占 퐉 or less and the average width may be 200 占 퐉 or less.

In describing the present invention, the term "laminated structure" may mean a structure formed after a metal layer is laminated. The laminated structure may include the metal layer formed along one side of the substrate.

In describing the present invention, the term "3D structure" may mean the microstructured structure or a plurality of microstructured structures. The 3D structure may refer to a structure formed by stacking microstructured structures on the microstructured structure.

A high-resolution 3D printing method using a micro-metal wire according to the present invention comprises the steps of: a) providing a substrate; b) irradiating a pulsed laser onto the substrate with a microwave metal wire to produce a metal layer formed by melting the microwave metal wire; And c) cooling the metal layer to produce an amorphous microstructured structure.

In detail, the present invention uses a micro-order metal wire and a pulse-wave laser to produce a microstructured structure of an amorphous phase.

In addition, the present invention can form a final micro-layered structure by forming a metal layer at a desired position by using the micro-metal wire.

Further, according to the present invention, by using the micro-metal wire, the surface of the final micro-layered structure can be smooth and the mechanical strength can be also excellent.

Such an effect of the present invention can precisely control the shape of the microstructured structure and make it possible to manufacture a microstructured structure more stably compared to the 3D structure finally produced using powder .

In addition, since the present invention uses a strong energy source such as an electron beam, a continuous laser, a plasma, or the like in order to melt a powder in comparison with a 3D printing method using a conventional powder, However, since the present invention uses a micro-order metal wire and a pulsed laser, a 3D structure of an amorphous phase can be produced.

More specifically, a metal or an alloy which can be used for the micro-metal wire may have a thermal conductivity of 10 W / mK or less and a melting point of 1000 占 폚 or less.

For example, the micro-metal wire may be a Mg-based amorphous alloy, a Ca-based amorphous alloy, an Al-based amorphous alloy, a Ti-based amorphous alloy, a Zr-based amorphous alloy, an Hf- , Fe-based amorphous alloy, Co-based amorphous alloy, Ni-based amorphous alloy, and Cu-based amorphous alloy.

As another example, the pulsed laser (referred to as pulsed laser or Quasi-CW fiber lasers) may be as commonly used in the art, but in order to achieve the object of the present invention, It is good if it can do. If a continuous wave laser is used in the step a), the energy applied to the micro-metal wire is increased, so that a 3D structure of a crystalline phase can be produced.

1 is a flowchart of a high-resolution 3D printing method using a micro-metal wire according to an embodiment of the present invention.

Referring to FIG. 1, a high-resolution 3D printing method using a micro-metal wire according to an embodiment of the present invention may include a substrate preparing step (S100), a laser irradiating step (S200), and a cooling step (S300).

The step of preparing the substrate (S100) may refer to a step of providing a substrate so that the metal layer may be formed on the substrate.

The substrate may be any one capable of supporting the above-described micro-metal wire, metal layer, or the like. For example, the substrate may be a rigid substrate such as glass, ceramic, or metal, but the present invention is not limited to the above-described substrate.

Next, the laser irradiation step S200 may refer to a step of irradiating the micro-metal wire with a pulsed laser after providing the substrate described above.

In the laser irradiation step S200, the micrometal wire may be formed so that the molten metal layer can be formed in a desired shape on the substrate, or an average diameter and a diameter of the micrometal wire can be adjusted so that an amorphous- The power of the pulse laser can be adjusted.

In detail, in a high-resolution 3D printing method using a micro-metal wire according to an embodiment of the present invention, the micro-metal wire may have an average diameter of 60 to 150 mu m. When the average diameter of the microwave metal wire is less than 60 mu m, a microstructure of a crystalline phase can be formed and control of a desired shape is difficult. If the mean diameter of the microwave metal wire is greater than 150 microns, the power of the pulsed laser must be increased or the dose of the pulsed laser must be increased to form the molten metal layer. In an embodiment of the present invention, when the average diameter of the microwave metal wire is greater than 150 mu m, the power of the pulsed laser must be increased by at least 1.5 times or more than 2 times in order to melt the microwave metal wire. Can be formed.

Further, in the high resolution 3D printing method using a micrometal wire according to an embodiment of the present invention, the pulse laser power may be 40 W or less and less than 90 W.

In detail, when the power of the pulse laser is less than 40 W, it takes an excessive time to melt the microwave metal wire, or the thermal energy supplied to the microwave metal wire is too low to form the metal layer. When the power of the pulse laser is 90 W or more, a heat affected zone (HAZ: Heat Affected Zone) may be formed between the prepared microstructured structure and the above-described substrate. That is, when the heat affected zone is formed between the microstructured structure and the substrate, the characteristics such as mechanical strength and corrosion resistance may be deteriorated in the final microstructured structure.

Meanwhile, in the high-resolution 3D printing method using the micro-metal wire according to an embodiment of the present invention, the average diameter of the micro-metal wire and the power of the pulse laser may satisfy the following relational expression 1:

[Relation 1]

E = a x D + b

Wherein E is the power (W) of the pulse laser irradiated on the unit area (탆 ² ) of the micro-metal wire, D is the average diameter (탆) of the micro-metal wire, ^{× 10 -4 ≤ a ≤ -1.1 ×} 10 -4, wherein b is ^{1.7 × 10 -3 ≤ b ≤ 4.7} × 10 - a ^2).

That is, in a high-resolution 3D printing method using a micro-metal wire according to a preferred embodiment of the present invention, a high-quality amorphous micro-layered structure can be manufactured when the condition of the above-mentioned relational expression 1 is satisfied.

Specifically, in the above-mentioned relational expression 1, when the average diameter of the microwave metal wire is 60 to 150 占 퐉 and the power of the pulse laser irradiated to the unit area (占 퐉 ² ) of the microwave metal wire is 40 W or more and less than 90 W, The height of one stacked structure is 50 to 200 mu m and the average width of the stacked structure is 100 to 300 mu m so that a 3D microstructured structure having an amorphous structure capable of controlling the shape can be manufactured.

Meanwhile, in a high-resolution 3D printing method using a micro-metal wire according to an embodiment of the present invention, the contact angle of the metal layer to the surface of the substrate may be 20 to 100 degrees.

In the present invention, the term "contact angle " may mean an angle between a straight line tangent to the radius of the metal layer from the contact point of the metal layer and the surface of the substrate.

A method of measuring the contact angle of the metal layer may be a method conventionally used in this field. For example, the contact angle of the metal layer can be calculated from the cross-sectional shape of the shape beads after melting the above-mentioned micro-metal wire and dropping the molten micro-metal wire onto the above-described substrate to form shape beads.

That is, according to one embodiment of the present invention, when the contact angle of the metal layer is less than 20 ° or more than 100 °, the shape beads may not be stacked or spread, and formation control may be difficult.

Finally, the cooling step (S300) may refer to a step of cooling the above-described metal layer to produce an amorphous microstructure.

In the cooling step (S300), cooling may mean naturally cooling.

Further, the laser irradiation step (S200) and the cooling step (S300) may be performed in the atmosphere.

In the high-resolution 3D printing method using a micro-metal wire according to an embodiment of the present invention, the micro-layered structure may be an amorphous phase. If the microstructured structure is not an amorphous phase, the mechanical strength of the microstructured structure may be rapidly lowered.

For example, the microstructured structure according to the present invention may have a Vickers hardness value of 770 to 850 kg / mm ² . When the Vickers hardness value range is satisfied, the microstructured structure according to the present invention can be applied to the aerospace industry, the automobile field, the semiconductor field, etc. where high strength is required.

In the present invention, the method for measuring the Vickers hardness is not particularly limited, and a general Vickers hardness measurement method known in this field can be used.

Meanwhile, a high-resolution 3D printing method using a micro-metal wire according to an embodiment of the present invention can produce a 3D structure in which the micro-stacked structures are stacked a plurality of times by stacking the micro-stacked structures.

In detail, the 3D structure may be manufactured by repeating the unit process using the laser irradiation step (S200) and the cooling step (S300) as one unit process.

In addition, the present invention includes an amorphous microstructured structure manufactured using the above-described high-resolution 3D printing method using a micro-metal wire.

Further, the present invention can include a high-resolution 3D structure in which an amorphous-phase microstructured structure is laminated.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples are only a few examples of the present invention, and the present invention is not limited by the following examples.

Examples 1 to 2 and Comparative Examples 1 to 4

An amorphous micro-metal wire made of a Cu-Zr binary alloy having a Cu content of 50 atomic% or more was prepared. A pulsed laser was applied to the micro-metal wire to form a metal layer on which the micro-metal wire was melted, on SUS304. The detailed experimental conditions are listed in Table 1 below.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Diameter (탆) 60 150 60 150 60 150 Power (W) 72 66 90 120 39 25 E (W / m ² ) 0.02548 0.00374 0.03185 0.00679 0.01083 0.00111 Frequency (Hz) 500 Speed (mm / sec) 20 Duty (%) 10 spot size (mm) About 0.35 Pulsed laser
Irradiation device qcw600 / 6000 laser

In Table 1, E means the power (W) of the pulse laser irradiated on the unit area (탆 ² ) of the micro-metal wire. The velocity (mm / sec) means the moving speed of the pulse laser. The duty (%) is referred to as a duty ratio and means a ratio of a high period H to a period T in a pulse having the same period. The spot size is circular and means the beam size (diameter) of the pulsed laser.

Also, referring to Table 1, the E value described in Example 1 compared to the E value described in Comparative Example 1 is reduced by about 20%, while the E value described in Example 2 compared to the E value described in Comparative Example 2 is reduced by about 45% . The difference in the reduction rate is due to the difference in the thermal conductivity depending on the diameter of the micro-metal wire, and therefore, the reduction ratio is different.

2 is a cross-sectional SEM photograph of the micro-metal wire used in Example 2 and Comparative Example 2. Fig. As shown in FIG. 2, it was confirmed that the micro-metal wire used in the present invention had a uniform diameter and a dense structure without pores.

FIG. 3 is a SEM photograph of the microstructured structure manufactured according to the second embodiment, and FIG. 4 is a SEM photograph of the microstructured structure manufactured according to the second comparative example. The left photograph shown in Figs. 3 and 4 shows a low magnification photograph, and the right photograph shows a high magnification photograph in which square dashed lines in the left photograph are enlarged. As shown in FIG. 3, the microstructured structure according to the present invention has a width of about 166.5 占 퐉. In addition, it can be seen that the micro-layered structure according to the present invention is a laminated structure in which the above-described metal layers are formed along the surface of the Fe substrate.

5 is a cross-sectional BSE photograph and an XRD graph of the microstructured structure manufactured according to the second embodiment. 6 is a cross-sectional BSE photograph and an XRD graph of the microstructured structure manufactured according to Comparative Example 2. FIG. Referring to Fig. 5, the microstructured structure 1 is formed on the above-described Fe substrate 2, and has a contact angle of about 86.5 DEG and an average height of about 100 mu m. Referring to the XRD graph shown in FIG. 5, it can be seen that the microstructured structure according to the present invention does not react with the above-described Fe substrate 2 and can maintain an amorphous phase structure with no change in crystal structure. On the other hand, referring to FIG. 6, it can be seen that the microstructured structure manufactured according to Comparative Example 2 has a contact angle of about 17.3 DEG and an average height of about 45 mu m. 6, it can be seen that the microstructured structure 3 produced according to Comparative Example 2 reacts with the above-described Fe substrate 4 to have a crystalline phase such as austenite or ferrite .

7 is a graph showing a correlation between E (power of a pulse laser irradiated per unit area) applied to a micro-metal wire and D (diameter) of a micro-metal wire based on the results of the above-described embodiment and comparative example.

(A) Crystalline Zone, (b) Amorphous Zone, and (c) Not Melting Zone depending on the sizes of E and D, as shown in FIG. 7, ). In detail, the Crystalline Zone is an area formed on the red line in FIG. 7, the Not Melting is an area formed below the black line in FIG. 7, and the Amorphous Zone is the area formed between the red line and the black line in FIG. More specifically, the amorphous zone is located between the red line drawn at E = -2.78 × 10 ^-4 × D + 0.0485 and the black line drawn at E = -1.08 × 10 ^-4 × D + 0.0173. Accordingly, the microstructured structure according to the present invention can be produced as a microstructured amorphous structure by controlling the above E, D, a and b.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereby. something to do. It is therefore intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

Claims (8)

a) providing a substrate;
b) irradiating a pulsed laser onto the substrate with a microwave metal wire to produce a metal layer formed by melting the microwave metal wire; And
and c) cooling the metal layer to produce an amorphous microstructured structure.
The method according to claim 1,
Wherein the micro-metal wire has an average diameter of 60 to 150 占 퐉.
3. The method of claim 2,
A high resolution 3D printing method using a microwave metal wire having a pulse laser power of 40 W or more and less than 90 W;
The method of claim 3,
The mean diameter of the micrometal wires and the power of the pulsed laser,
High resolution 3D printing method using a micro-metal wire satisfying the following relational expression 1:
[Relation 1]
E = a x D + b
Wherein E is the power (W) of the pulse laser irradiated on the unit area (탆 ² ) of the micro-metal wire, D is the average diameter (탆) of the micro-metal wire, ^{× 10 -4 ≤ a ≤ -1.1 ×} 10 -4, wherein b is ^{1.7 × 10 -3 ≤ b ≤ 4.7} × 10 - a ^2).
The method according to claim 1,
Wherein the unit process is repeatedly performed using the steps b) and c) as one unit process.
The method according to claim 1,
In the step b)
Wherein the contact angle of the metal layer with respect to the surface of the substrate is 20 to 100 deg.
The method according to claim 1,
Wherein the Vickers hardness of the microstructured structure is 770 to 850 kg / mm ² .
8. A microstructure of amorphous phase produced by a high resolution 3D printing method according to any one of claims 1-7.

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