KR20070029456A - Surface composite and fabrication method of the same - Google Patents

Abstract

A surface composite material having improved corrosion resistance, wear resistance, high temperature stability, hardness and strength, and a method capable of manufacturing the surface composite material easily and continuously are provided. A surface composite material comprises: (i) a substrate; and (ii) an ion(Fe)-based crystalline surface composite layer including an austenitic matrix which is formed on the substrate and comprises iron, chromium and nickel, and a carbide-base or a boride-based precipitation-strengthened phase distributed in the austenitic matrix. The carbide-based precipitation-strengthened phase is titanium carbide(TiC), tungsten carbide(WC), vanadium carbide(VC), or a mixture thereof. The boride-based precipitation-strengthened phase is chromium boride(Cr2B), molybdenum boride(MoB), titanium boride(TiB2), or a mixture thereof. The surface composite layer includes the precipitation-strengthened phase and the matrix in a volume ratio of 1:0.5 to 1:10. The surface composite layer has a thickness of 0.3 to 3.0 mm. The surface composite layer and the substrate have an interface formed between them, and a heat affected zone with a thickness of 0.15 to 2.5 mm is formed along the interface on a lower portion of the interface. The substrate is made of iron, copper, aluminum, or titanium.

Description

Surface composite and fabrication method of the same

1A to 1E are conceptual views showing step by step of the manufacturing method of the present invention.

FIG. 2A is a scanning electron micrograph showing a surface composite layer of the surface composite material subjected to one-time compounding according to Example 1 of the present invention. FIG.

2B is a scanning electron micrograph showing the surface composite layer of the surface composite material subjected to two complexes according to Example 2 of the present invention.

3A is a high magnification scanning electron micrograph showing a surface composite layer of a surface composite material subjected to one-time compounding according to Example 1 of the present invention.

3B and 3C are high magnification scanning electron micrographs showing the surface composite layer of the surface composite material subjected to two complexes according to Example 2 of the present invention.

Figure 3d is a scanning electron micrograph showing the surface layer spray-coated using the HVOF method according to Comparative Example 1 of the present invention.

Figure 4 is a transmission electron micrograph showing the crystals formed in the surface composite layer of the surface composite material subjected to two complexes according to Example 2 of the present invention.

5A, 5B, and 5C are graphs showing the hardness of the surface composite layer of the surface composite material prepared in Example 1, Example 2, and Comparative Example 1, respectively.

Figure 6 is a graph showing the hardness of Examples 1, 2, Comparative Example 1 and the base material used herein measured by temperature.

7A and 7B are scanning electron micrographs of the surface composite materials prepared in Examples 1 and 2 of the present invention, respectively, and after the abrasion test, their cross sections were observed.

<Explanation of symbols for the main parts of the drawings>

10: iron (Fe) amorphous alloy powder 12: the base material

16: single layer surface composite layer 18: single layer surface composite material

20: 2-layer surface composite layer 24: 2-layer surface composite material

The present invention relates to a surface composite material and a manufacturing method thereof, and more particularly, to a surface composite material having improved corrosion resistance, abrasion resistance, high temperature stability, hardness, and strength, and a manufacturing method capable of easily and continuously producing the surface composite material. It is about.

In recent years, there is an increasing demand for materials having properties that can withstand extreme environments such as high temperature, corrosion, and wear. Since the surface properties of the material is very important to satisfy the above properties, various surface treatment technologies have been developed to improve properties such as high temperature oxidation resistance, corrosion resistance, and wear resistance of the material. Surface treatment technology is a fundamental technology that is required in a variety of industries, as well as aerospace, automotive, electronics, medical implants related to biotransport materials.

Conventional surface treatment methods include physical deposition methods such as ion implantation and plasma spray coating, and thermochemical methods such as nitriding, carburizing and boriding. Surface treatment methods; The material surface-treated using the above method is remarkably improved in high temperature oxidative resistance, corrosion resistance, and abrasion resistance compared to conventional materials, and the surface-treated materials may be usefully used in various industrial fields.

However, in the case of the physical vapor deposition method, the formed coating layer is thin and the interfacial bonding strength is weak, there is a disadvantage that the interface separation occurs when used for a long time. The disadvantage is that surface-treated materials are unstable for use in extreme environments such as high temperatures, corrosion and wear.

In order to overcome the disadvantages of the conventional surface treatment method, a method of hardening the surface or compounding the surface by directly projecting the high energy accelerated electron beam of a high-energy electron beam accelerator to the material in the air It is trying. High-energy accelerated electron beams have twice the thermal efficiency of laser beams, and because they can project electron beams only on selected areas in a short time, very large heat inputs can be obtained. In addition, it is possible to work directly in the atmosphere, continuous processing is possible, and a large area can be easily processed at once, which is advantageous for the manufacture of large parts and mass production. In addition, the high-energy beam projection method can obtain a fast cooling rate at the surface of the material, and the energy input does not have a great influence on the substrate, thus maintaining the properties of the substrate and obtaining desired surface properties. . In addition, since the surface layer is melted and then resolidified, there is almost no problem of bonding at the interface, and a stable or metastable phase of excellent physical properties can be obtained by overcoming the equilibrium employment limit due to rapid cooling rate during solidification. For this reason, studies are being actively conducted to form a surface composite layer of ceramics or amorphous alloys such as carbides, borides and nitrides on the surface of iron-based alloys or titanium alloys by using high energy beams. have.

If the ceramic or amorphous powders are uniformly distributed on the surface of the metal and the electron beam is projected, the surface composite material can be manufactured by melting and resolidifying the surface of the powder and the base metal. The research has mainly focused on the improvement of wear resistance, the improvement of microstructure, and the application as a high temperature material.

However, when the electron beam is projected onto the amorphous alloy powder having low amorphous forming ability, many crystal phases are formed if sufficient cooling rate is not secured during resolidification after melting of the powder. As the softening occurs rapidly, there is a limit to the improvement of the mechanical properties.

As such, the existing material development method has a limitation in developing a material having innovative physical properties. Thus, the surface composite material is manufactured to improve the hardness, wear resistance, fracture toughness and high temperature properties of the surface composite layer by uniformly dispersing the crystal phase in the matrix structure. There is a need to do so.

The first technical problem to be achieved by the present invention is to provide a surface composite material having excellent corrosion resistance, high temperature stability and wear resistance, excellent hardness and strength and uniform physical properties.

The second technical problem to be achieved by the present invention is to provide a method for producing the surface composite material.

The present invention to achieve the first technical problem,

(i) the substrate,

(ii) iron (Fe) formed on the base material and containing an austenitic matrix containing iron, chromium and nickel, and a carbide-based or boride-based precipitation strengthening image distributed within the austenitic matrix; System crystalline surface composite layer

It provides a surface composite material comprising a.

The present invention to achieve the second technical problem,

A first step of applying iron (Fe) -based amorphous alloy powder to the base material surface;

A second step of pressing for densification of the powder; And

By uniformly projecting a high energy accelerated electron beam onto the densified powder layer, the iron (Fe) amorphous alloy powder is melted and solidified to form an iron (Fe) crystalline surface composite layer having an iron (Fe) surface hardening layer. Third step forming

It provides a method for producing a surface composite material comprising a.

The method for producing a surface composite material of the present invention is a very simple method that can be continuously performed in the air, and it can be used to produce the surface composite material at low cost. In addition, the surface composite material formed by the manufacturing method is excellent in corrosion resistance, abrasion resistance, high temperature stability, hardness and strength can be used as a useful material in aerospace / automotive engine parts, nuclear reactor parts and the like.

Hereinafter, the present invention will be described in more detail.

The first aspect of the present invention,

(i) the substrate,

(ii) forming an austenite matrix formed on the base material and containing iron, chromium and nickel, and a carbide-based or boride-based precipitation strengthening image distributed in the austenitic matrix; Iron (Fe) crystalline surface composite layer containing

It provides a surface composite material comprising a.

The base material is preferably selected to be excellent in ductility and fracture toughness, and examples of such a base material include, but are not limited to, iron, copper, aluminum, titanium and the like.

The surface composite layer is separated from each other by forming an interface with the base material, and a heat affected zone (HAZ) is formed on the base material at a predetermined thickness along the interface under the interface.

The thickness of the surface composite layer varies depending on the type of base material, the amount of energy of the high energy accelerated electron beam projected at the time of manufacture, the composition and the coating thickness of the amorphous alloy powder applied at the time of manufacture, but is preferably 0.3 mm to 3.0 mm. . If the thickness of the surface composite layer is less than 0.3 mm, it is difficult to expect the improvement of the intended surface properties, and in particular, the base metal cannot be sufficiently protected from the phenomenon such as wear and corrosion. It is uneconomical if the thickness of the surface composite layer exceeds 3.0 mm.

In addition, the thickness of the heat affected zone is 0.15 mm to 2.5 mm, depending on the type of the base material, the amount of energy of the high energy accelerated electron beam projected at the time of manufacture, and the coating thickness of the amorphous alloy powder applied at the time of manufacture. .

The austenite base includes iron, chromium, and nickel, and may further include cobalt, molybdenum, boron, copper, silicon, carbon, and the like.

The carbide-based precipitated enhanced image includes, but is not limited to, for example, titanium carbide (TiC), tungsten carbide (WC), vanadium carbide (VC), or mixtures thereof.

The boride-based precipitated enhanced image includes, but is not limited to, for example, chromium boride (Cr ₂ B), molybdenum boride (MoB), titanium boride (TiB ₂ ), or a mixture thereof.

The carbide-based or boride-based precipitation-enhanced image exists in various forms of tissue in the austenitic matrix. The shape may have a solidification cell structure such as linear, circular, elliptical, and branched from these shapes, or may have a bamboo leaf structure perpendicular to the interface.

The volume ratio of the precipitated reinforcement image and the matrix is preferably 1: 0.5 to 1:10. If the volume of the precipitated hardened phase is too small out of the range, the strengthening effect of physical properties due to precipitation strengthening is inferior, and if the volume of the precipitated hardened phase is too large beyond the range, the toughness of the surface composite layer is reduced due to fragile crystal phases. There is this.

A second aspect of the invention is a method for producing an amorphous surface composite material,

A first step of applying iron (Fe) -based amorphous alloy powder to the base material surface;

A second step of pressing for densification of the powder; And

By uniformly projecting a high energy accelerated electron beam onto the densified powder layer, the iron (Fe) amorphous alloy powder is melted and solidified to form an iron (Fe) crystalline surface composite layer having an iron (Fe) surface hardening layer. Third step forming

It provides a method for producing a surface composite material comprising a.

Referring to the drawings the manufacturing method is as follows.

1A to 1E are schematic diagrams showing a method for producing a surface composite material including the iron (Fe) -based crystalline surface composite layer of the present invention.

First, as shown in FIG. 1A, iron (Fe) -based amorphous alloy powder 10 is applied onto a base material, and then pressure is applied to densify the alloy powder 10.

The iron (Fe) -based amorphous alloy powder 10 preferably has an average particle diameter of 60 μm to 120 μm. If the average particle diameter of the alloy powder is less than 60 μm is difficult to manufacture and handle, if the average particle diameter of the alloy powder exceeds 120 μm there is a disadvantage that uniform mixing is difficult and porosity increases in the densification process.

The iron (Fe) -based amorphous alloy powder 10 includes 25 parts by weight to 45 parts by weight of iron, 25 parts by weight to 45 parts by weight of chromium, and 10 parts by weight to 30 parts by weight of nickel based on 100 parts by weight. If the iron, chromium, and nickel content is in the above range, crystals are well formed upon cooling after melting.

In addition, the alloy powder 10 is amorphous, and may further include cobalt, molybdenum, boron, copper, silicon, carbon, and the like in addition to iron, chromium, and nickel. Examples of the alloy powder 10 include, but are not limited to, Armacor ^™ C ⁺ manufactured by Liquidmetal Technologies.

Conventionally, in order to project a high energy accelerated electron beam, a fluoride compound and / or an oxide compound were mixed with an amorphous alloy powder as a flux, but the iron (Fe) amorphous alloy powder of the present invention is chromium, boron, silicon. It does not necessarily need to be used with a solvent because it contains a component having a self fluxing effect such as nickel, carbon, and the like.

Preferably, the iron (Fe) amorphous alloy powder 10 is dried at a temperature of about 120 ° C. to 200 ° C. for 1 to 4 hours before application, thereby to surface the iron (Fe) amorphous alloy powder 10. Provided by removing the moisture present in the. In this way, by removing the moisture on the surface of the amorphous alloy powder, it is possible to obtain the effect of preventing the deterioration of the amorphous by the formation of pores and oxides that may occur in the tissue during solidification.

The iron (Fe) amorphous alloy powder 10 is uniformly applied to the base material 12, and then pressurized in the mold to densify the alloy powder 10 and adhere to the base material.

The method of applying the iron (Fe) amorphous alloy powder 10 on the base material 12 is not particularly limited, and a method of uniformly distributing the alloy powder 10 on the base material is sufficient. The mold is not particularly limited as long as the mold maintains the alloy powder 10 uniformly distributed so that the alloy powder 10 does not deviate from the base metal 12.

The method of pressurizing may use an apparatus which can apply mechanical pressure to the alloy powder 10, for example, an apparatus such as a press, but is not limited thereto. It is preferable that the pressure range of the said pressurization is 30 kPa-400 kPa. When the pressurization pressure is less than 30 kPa, the densification of the alloy powder 10 may not be sufficiently achieved. When the pressurization pressure exceeds 400 kPa, the base metal may be damaged and it is uneconomical.

The iron (Fe) amorphous alloy powder pressed and densified as described above preferably has a density of 0.2 g / cm ³ to 0.8 g / cm ³ . If the density is less than 0.2 g / cm ³ , the heat transfer to the base material is too much, resulting in a large amount of melting of the base material and a tendency to deviate from the desired composition due to excessive mixing with the amorphous alloy powder. When the density exceeds 0.8 g / cm ³ , the heat transfer to the base material is too small, and the bonding between the base material and the surface composite layer may be insufficient.

As shown in FIG. 1B, a high energy accelerated electron beam is projected onto the densified iron (Fe) amorphous alloy powder 10 using the high energy electron beam accelerator device.

In general, the iron (Fe) amorphous alloy powder 10 is densified in a fixed high energy electron beam accelerator device, and the high energy accelerated electron beam is transferred to the alloy powder 10 while the applied base metal 12 moves at a constant speed. Evenly projected on. When the high-output focused energy obtained by accelerating the electron beam is directly transmitted to the base metal, the energy is instantly converted into thermal energy, which can act as a powerful heat source. That is, the surface composite layer is formed by instantaneously dissolving the iron (Fe) amorphous alloy powder applied to the surface of the base material and undergoing a solidification process through cooling.

The amount of heat received by the base material 12 and the iron (Fe) amorphous alloy powder 10 is proportional to the beam power (electron beam energy x beam current), and inversely proportional to the electron beam moving speed and scanning width. With this electron beam projection, as the amorphous alloy powder 10 and the base material 12 are melted and solidified, a crystalline phase is formed in the molten layer, thereby making it possible to manufacture a crystalline surface composite material. At this time, since the surface layer is melted and then undergoes a solidification process, bonding problems at the interface hardly occur.

High-energy accelerated electron beam has more than twice the thermal efficiency of laser beam, so it is easy to melt alloys or ceramics with high melting point, and uniform heating and cooling makes it hard to form pores or cracks inside the material. The metastable phase of excellent physical properties can be obtained by overcoming the equilibrium employment limit due to the rapid cooling rate. In addition, there is an advantage that a large area (about 72 m ² per hour) can be processed at a time by using the relative motion of the electron beam scanning device and the specimen.

The electron energy of the high energy accelerated electron beam is preferably 0.5 MeV to 1.5 MeV. If the electron energy is less than 0.5 MeV it may not be able to sufficiently melt the amorphous alloy powder applied to the surface of the base material, if the electron energy exceeds 1.5 MeV heat input may increase the high temperature oxidation and vaporization may occur.

Through the above process, the single-layer surface composite material 18 including the single-layer crystalline surface composite layer 16 having the structure as shown in FIG. 1C is formed. As used herein, the term "monolayer" means that the surface composite layer 16 is formed through one-time compounding. Similarly, the term "two-layer" or "multi-layer" as used herein should be understood to mean the number of times of compounding. In addition, the term "complexation" as used herein refers to a cycle comprising the provision, application and pressurization of the amorphous alloy powder as described above, and the projection of a high energy accelerated electron beam.

The compounding may be performed only once, but may be repeated 2 to 10 times as necessary to form the surface composite layer in multiple layers.

Hereinafter, the structure and effects of the present invention will be described in more detail with specific examples and comparative examples, but these examples are only intended to more clearly understand the present invention and are not intended to limit the scope of the present invention. In Examples and Comparative Examples, physical properties were evaluated in the following manner.

<Example 1>

As the iron (Fe) amorphous alloy powder, an alloy powder known under the commercial name Armacor ^™ C ⁺ was used. The chemical composition of the Armacor ^TM C ⁺ is as described in Table 1 below.

TABLE 1

element Cr Ni Co Mo B Cu Si Fe Content (weight%) 30 17 10 4 4 2.5 1.5 31

The Armacor ^™ C ⁺ alloy powder was dried at 130 ° C. to 170 ° C. for 2 hours. The alloy powder was then applied to a surface of a general low carbon steel substrate having a width of 50 mm, a length of 50 mm, and a thickness of 25 mm in a mold having a density of 0.45 g / cm ³ , and then pressurized to 120 kPa using a press. The alloy powder was pressurized with.

Then a high energy electron beam accelerator was projected onto the pressurized alloy powder using a high energy electron beam accelerator device (model ELV-6, a product manufactured and marketed by Budker Nuclear Physics Laboratory, Russia). The high energy accelerator device had an electron energy range of 0.5 MeV to 1.5 MeV, a maximum power of 100 kW, a maximum beam current of 70 mA, and a maximum electron beam diameter of 1.27 cm. Specific projection conditions applied in this example are as described in Table 2 below.

TABLE 2

Projection parameters First compounding Second compound Electronic energy 1.4 MeV 1.4 MeV Beam moving speed 35 mm / s 35 mm / s Beam scan width 50 mm 50 mm Beam current 55 mA 55 mA Scanning frequency 19 Hz 19 Hz Beam size (diameter) 11 mm 11 mm atmosphere Waiting Waiting

In Table 2, electron beam projection was performed by operating the high energy electron beam accelerator device according to the projection condition of the first compounding. The surface composite material including the single layer iron (Fe) -based crystalline surface composite layer obtained therefrom was denoted by F1.

<Example 2>

On the surface of the F1 surface composite material prepared in Example 1, the second compounding was carried out in the same manner as the method described in Example 1 above. However, the projection conditions of the high-energy electron beam accelerator device projected the high-energy accelerated electron beam as indicated by the second compounding of Table 2 above. The surface composite material including the single layer iron (Fe) -based crystalline surface composite layer obtained therefrom was denoted by F2.

Comparative Example 1

The iron (Fe) amorphous alloy powder used in Example 1 was spray-coated on the same low carbon steel base material as used in Example 1 by using the High Velocity Oxygen Fuel (HVOF) method.

<Evaluation Example>

In order to observe the cut surface and the surface composite layer of each of the F1 and F2 surface composite materials prepared according to Example 1 and Example 2, each of the F1 and F2 surface composite materials was cut and polished in parallel with the electron beam projection direction, and then glycerol Etched with 45 mL, 15 mL nitric acid, 30 mL HF solution. The microstructures of the surface composite layer, the interface portion, and the base material were observed under an optical microscope, and F1 and F2 surface composite materials were shown in FIGS. 2A and 2B, respectively.

As can be seen in FIG. 2, the amorphous alloy powder coated by the electron beam projection and the surface portion of the carbon steel were melted and solidified to form a crystalline surface composite layer. (Parts indicated by arrows in FIGS. 2A and 2B). In general, the surface-reinforced surface composite material prepared without the addition of flux has poor surface roughness and contains many pores and cracks. However, in the specimens of the F1 and F2 surface composite materials, the surface is not added without solvent. It was observed that it was flat and glossy, and there were no pores or cracks.

As shown in FIG. 2a, the thickness of the surface composite layer of the F1 specimen is about 1.3 mm, and the microstructure is uniform throughout. As shown in Fig. 2B, the surface composite layer thickness of the F2 specimen is about 1.9 mm, thicker than that of the F1 specimen, and the interface between the first composite surface composite layer and the second composite surface composite layer is also found. In the case of F2, as shown in FIG. 2B, the area of about 0.2 mm above the surface composite layer / base material interface indicated by the black triangular arrow remains the same structure as the F1 specimen surface composite layer. Surface composite layers consist of different types of tissue. The formation of the interface between the surface composite layer of the first composite and the surface composite layer of the second composite as described above is sufficient to heat the amount of heat input of the electron beam projected in the second composite to completely melt the surface composite layer formed in the first composite. Seems to have not.

In addition, it was observed that a heat affected zone (HAZ) of about 1.5 mm thickness was present under the surface composite layer.

3A, 3B, and 3C show the microstructures of the surface composite layer of the first composite, the surface composite layer of the second composite, and the surface composite layer / base material interface, respectively, in detail by scanning electron microscopy (SEM). Figure 3a is a photograph of the surface composite layer and surface composite layer / matrix interface of the F1 specimen, it can be observed that the solidification cell structure is well developed, and the crystal phases are densely deposited in the solidification cell boundary region in a layered form. . In addition, the surface composite layer between the surface and the heat-affected portion forms a solidified cell structure as in the upper portion of FIG. 3A. Meanwhile, as shown in FIG. 3B, the surface composite layer and the surface composite layer / base material interface of the F2 specimen are composed of a well-developed solidification cell structure such as the F1 specimen, and the size of the solidification cell formed therein is larger than that of the F1 specimen.

On the other hand, as can be seen in Figure 3c the majority of the surface composite layer of the F2 is composed of a bamboo leaf structure (bamboo leaf structure) formed in a direction perpendicular to the interface rather than in the form of a coagulation cell. The bamboo leaf tissue is similar to the tissue commonly seen when the chromium content is high in stainless steel.

The cross-sectional photograph of the specimen sprayed by the HVOF method on the surface in Comparative Example 1 is shown in Figure 3d. The thickness of the coating layer of Comparative Example 1 is about 0.2 mm, and the boundary between the base material and the coating layer is clear and the interface bonding strength is weak, which may act as an interface separation and main breakdown point. Compared with FIG. 3A and FIG. 3D, since the thickness of the surface compounding is thick and the interface bonding is excellent, the surface compounding using the high-energy accelerated electron beam according to the present invention can obtain a much better surface strengthening effect. .

Figure 4 is a photograph of the solidified structure of the iron (Fe) -based surface composite layer observed by transmission electron microscopy, XRD analysis (X-Ray Diffraction Analysis) and EDS analysis that the crystal phase is Cr ₂ B and Cr ₁₉ Fe ₇₀ Ni ₁₁ , respectively (Energy Dispersive Spectroscopy). The XRD analysis results of the specimens of Example 1, Example 2, and Comparative Example 1 are shown in FIGS. 8A, 8B, and 8C.

5a, 5b and 5c is a composite layer to examine the physical properties of the surface composite layer of the material prepared by F1 and F2 prepared in Example 1 and Example 2, and Comparative Example 1 by HVOF (High Velocity OxyFuel) The change in microhardness from the surface was measured with a Vickers hardness tester under a load of 300 g, respectively. As described above, it can be seen that the F2 material has better physical properties and uniform structure state than the F1 material, has better physical properties of the surface composite layer, and has uniform physical properties. On the other hand, in the case of HVOF composite material of Comparative Example 1, the hardness is high, but the physical properties of the composite layer are not uniform, and the interfacial force is weak and the continuity of the interface portion is weak, so that the separation between the base material and the surface composite layer is high. It turned out that it is inferior to Example 2 and.

FIG. 6 is a measurement of fine hardness according to temperature for F1 and F2 prepared from Examples 1 and 2 and HVOF, and it can be seen that the high temperature properties of F1 and F2 are excellent. . In the thermal spray coating material of Comparative Example 1 at a high temperature of more than 600 ℃ sharply decreases the fine hardness, F1 and F2 it can be seen that it has a fairly stable high temperature properties. In addition, it was found that the wear resistance was also improved 2 to 6 times through the wear resistance test. The wear resistance test was performed by performing a wear test for 5 minutes under a 20 kg load using a pin-on-disk wear tester. As a result, the wear amount of F1 was 56.95 mg, the wear amount of F2 was 44.7 mg, and the wear amount of the base material was 148.7 mg. That is, the wear resistance of F2 was improved by about 20% compared to F1, and the physical properties were improved by about 300% compared to the base material.

7A and 7B are scanning electron micrographs of cross-sections of specimens subjected to abrasion testing for F1 and F2 prepared from Examples 1 and 2, wherein the deformed region of F2 is much shallower. It can be seen that the structures of the fine borides have excellent wear resistance.

Although described in detail with respect to preferred embodiments of the present invention as described above, those of ordinary skill in the art, without departing from the spirit and scope of the invention as defined in the appended claims Various modifications may be made to the invention. Therefore, changes in the future embodiments of the present invention will not be able to escape the technology of the present invention.

After coating iron (Fe) amorphous alloy powder on the surface of the base material, melting and solidifying using high-energy accelerated electron beam to produce a surface composite material having a surface composite layer of uniform thickness on the base material surface. Compared to the above, there is an effect that the material can be easily and mass produced continuously with improved physical properties. In addition, by producing a surface composite material having sufficient ductility and fracture toughness by using the iron (Fe) amorphous alloy powder, which has excellent physical properties such as corrosion resistance, abrasion resistance, high temperature stability, hardness and strength, and is relatively inexpensive. Thus, it can be used as a useful material for aerospace / automotive engine parts, reactor parts and the like.

Claims (14)

(i) the substrate, (ii) iron (Fe) formed on the base material and containing an austenitic matrix containing iron, chromium and nickel, and a carbide-based or boride-based precipitation strengthening image distributed within the austenitic matrix; System crystalline surface composite layer Surface composite material comprising a. The surface composite material as claimed in claim 1, wherein the carbide-based precipitation strengthening image is titanium carbide (TiC), tungsten carbide (WC), vanadium carbide (VC), or a mixture thereof. The surface composite material as claimed in claim 1, wherein the boride-based precipitation strengthening image is chromium boride (Cr ₂ B), molybdenum boride (MoB), titanium boride (TiB ₂ ), or a mixture thereof. 2. The surface composite material as claimed in claim 1, wherein the precipitated strengthened image and the matrix have a volume ratio of 1: 0.5 to 1:10. The surface composite material as claimed in claim 1, wherein the surface composite layer has a thickness of 0.3 mm to 3.0 mm. The surface composite according to claim 1, wherein an interface is formed between the surface composite layer and the base material, and a heat affected part having a thickness of 0.15 mm to 2.5 mm is formed along the interface under the interface. material. The method for producing a surface composite material according to claim 1, wherein the base material is iron, copper, aluminum, or titanium. A first step of applying iron (Fe) -based amorphous alloy powder to the base material surface; A second step of pressing for densification of the powder; And By uniformly projecting a high energy accelerated electron beam onto the densified powder layer, the iron (Fe) amorphous alloy powder is melted and solidified to form an iron (Fe) crystalline surface composite layer having an iron (Fe) surface hardening layer. Third step forming Method for producing a surface composite material comprising a. The method of claim 8, wherein the electron energy range of the high energy accelerated electron beam is 0.5 MeV to 1.5 MeV. The method for producing a surface composite material according to claim 8, wherein the densifying pressure is 30 kPa to 400 kPa. 10. The method of claim 8, wherein the density of the iron (Fe) amorphous alloy powder after compacting is 0.2 to 0.8 g / cm ³ . The method for producing a surface composite material according to claim 8, wherein the iron (Fe) amorphous alloy powder has an average particle diameter of 60 µm to 120 µm. 10. The method of claim 8, wherein the first to third steps are repeated two to ten times to form a surface composite layer in multiple layers. The surface composite material as claimed in claim 8, further comprising, before the first step, drying the iron (Fe) amorphous alloy powder at a temperature of 120 ° C to 200 ° C for 1 hour to 4 hours. Method of preparation.

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