KR20190050561A - Aluminum-Titanium Different Functionally Graded Composite Materials and Manufacturing method thereof - Google Patents

Abstract

The present invention relates to an aluminum-titanium heterogeneous tilting composite material and a manufacturing method thereof and, more specifically, to a heterogeneous tilting composite material and a manufacturing method thereof, wherein the heterogeneous tilting composite material comprises: a surface layer comprising titanium powder; a support layer comprising aluminum powder; and a heterogeneous material inclined layer comprising a plurality of mixture layers in which the aluminum powder and the titanium powder are mixed with each other between the surface layer and the support layer. Accordingly, the surface layer and the support layer can be strongly bonded to each other. Moreover, the aluminum-titanium heterogeneous tilting composite material provides improved corrosion resistance, weight reduction, and high strength.

Description

TECHNICAL FIELD The present invention relates to an aluminum-titanium heterostructure composite material and a method for manufacturing the same.

The present invention relates to an aluminum-titanium heteroepitaxial composite material and a method of manufacturing the same, and more particularly, to an aluminum-titanium heteroepitaxial composite material and a method for manufacturing the composite material, which not only exhibits excellent corrosion resistance but also exhibits light weight and high strength.

In general, spark plasma sintering (SPS) is a method of sintering by applying a direct current pulse current in the direction parallel to the pressing direction while pressing the powder in one axis. In this method, pressure, low voltage and high current And the high energy of the plasma generated instantaneously by the spark generated at this time is applied to electric field diffusion, thermal diffusion and the like. The sintering temperature can be lowered by 200 to 500 占 폚 and the sintering can be completed in a short time including the temperature rise and the holding time as compared with the conventional hot pressing method (Hot Press), so that the power consumption is greatly reduced, It is also applicable to materials that are inexpensive, do not require skill in sintering technology, and are difficult to process in ovary and high temperature.

2. Description of the Related Art In recent years, spark plasma has been applied to sintering powder as well as metal bonding technology. Plasma bonding is performed by heating the joint using a heat generated through a direct current while pressing the joint, such as sintering. At this time, new metal bonds are formed and bonded between the materials by the diffused atoms.

On the other hand, titanium has the advantage that it is light in weight with a small specific gravity enough to give strength similar to that of iron even at a weight of about half of iron, and has a passive film in water or air near room temperature and has excellent corrosion resistance next to gold or platinum However, since the melting point is as high as about 1670 ° C, it is difficult to manufacture a complete ingot, and it is oxidized rapidly at a high temperature to lose the properties required originally, so that hot working and welding are difficult and cold working is also difficult due to high yield stress There are disadvantages. In addition, titanium has a stable oxidation film at room temperature to prevent corrosion. However, it is highly reactive at a high temperature of 600 ° C or higher, so it is contaminated with elements such as O ₂ , N ₂ , and H ₂ to lower corrosion resistance, or porosity And it has a property to degrade not only the corrosion resistance but also the mechanical properties, and it is disadvantageous in that it is expensive.

The aluminum alloy is an alloy of aluminum (Al) and a metal such as copper (Cu) or magnesium (Mg) added. It is lighter than steel and has excellent workability and corrosion resistance. It has excellent non-rigidity, Although it is used as a structure of a device, it has a disadvantage in that it has a low mechanical strength.

Accordingly, when composite materials of aluminum and titanium are utilized, it is possible to supply materials optimized for application as composite materials having excellent mechanical strength, corrosion resistance and light weight at the same time, thereby reducing cost and improving performance .

As a method for manufacturing the titanium alloy-aluminum alloy composite material as described above, casting, which is a typical processing method for alloying, may be considered.

However, when the composite material is produced by casting, the combustion due to the ignition of aluminum during the casting process due to the extreme melting point difference between the two materials (titanium: about 1675 ° C, aluminum alloy: about 660 ° C) There is a problem that titanium alloy-aluminum alloy composite materials having excellent physical properties are difficult to produce at present. In particular, it is impossible to manufacture an Al-Ti composite material composed of an inclined layer having a function as a liquid phase process.

Accordingly, there is a need to develop a technique for manufacturing a titanium alloy-aluminum alloy composite material which overcomes the above problems and has excellent mechanical strength, corrosion resistance and light weight.

Korean Patent Publication No. 10-2001-0021912 (Mar. 15, 2001)

The object of the present invention is to solve the problems of the prior art by joining the surface layer and the support layer using a different material inclined layer composed of a mixed powder of aluminum powder and titanium powder between a support layer made of aluminum powder and a surface layer made of titanium powder The present invention is to provide an aluminum-titanium heteroepitaxial composite material which suppresses delamination and exhibits excellent corrosion resistance, light weight and high strength properties, and a method for producing the same.

In order to achieve the above object, the present invention provides a surface layer made of titanium powder; A support layer made of aluminum powder; And a heterogeneous material inclined layer composed of a plurality of mixed layers in which aluminum powder and titanium powder are mixed between the surface layer and the support layer, wherein the different material inclined layer is formed such that the content of the titanium And the mixed layer of any one of the plurality of mixed layers has a titanium content higher than that of the mixed layer adjacent to the direction of the support layer.

Wherein the aluminum powder is an aluminum alloy powder further comprising any metal selected from the group consisting of manganese (Mn), silicon (Si), copper (Cu), magnesium (Mg), tin (Sn) Lt; / RTI >

The titanium powder may be at least one selected from the group consisting of vanadium (V), molybdenum (Mo), zirconium (Zr), aluminum (Al), iron (Fe), nickel (Ni), cobalt (Co), silicon Titanium (Nb), and a combination of any of these metals.

And the difference value of the titanium powder content between any one of the plurality of mixed layers and the adjacent mixed layer may be 10 to 30% by volume.

The two mixed layers located on the symmetrical layer based on the mixed layer positioned at the center among the plurality of mixed layers may have symmetrical differences in the content of titanium powder with the adjacent layers.

The Vickers hardness of the aluminum-titanium hetero-gradient functional composite may be 120 to 460 Hv.

The present invention also provides a method of manufacturing a semiconductor device comprising the steps of: providing a support layer made of aluminum powder; laminating a different material inclined layer composed of a plurality of mixed layers in which aluminum powder and titanium powder are mixed on the support layer; And sintering the laminated support layer, the different material inclined layer and the surface layer using a spark plasma sintering process, wherein the different material inclined layer is formed such that as each mixed layer is disposed in the direction of the support layer from the surface layer Wherein the content of titanium is decreased and the content of titanium is higher than that of a mixed layer in which one of the plurality of mixed layers is adjacent to the direction of the support layer.

The step of sintering using the spark plasma sintering process may be performed at a pressure of 30 to 200 MPa, at a temperature of 400 to 600 ° C and a holding time of 5 to 10 minutes.

The present invention provides an aluminum-titanium heteroepitaxial composite material having an inclined layer in which the physical properties between aluminum and titanium are gradually changed, thereby maximizing the stress relaxation effect between dissimilar materials to improve the interfacial bonding strength and suppressing the interlayer peeling phenomenon can do.

The present invention can also provide an aluminum-titanium hetero-graded composite material which can be applied to a group of parts requiring strength, corrosion resistance and light weight at the same time.

The present invention can also provide a method for manufacturing an aluminum-titanium hetero-gradient functional composite material which can produce a more rigid composite material by including a spark plasma sintering step.

FIG. 1 is a cross-sectional view showing an aluminum-titanium hetero-gradient functional composite according to an embodiment of the present invention.
2 is a conceptual diagram schematically showing a spark plasma sintering apparatus according to an embodiment of the present invention.
3 is a conceptual diagram schematically showing a spark plasma sintering process according to an embodiment of the present invention.
4 to 13 are HV images obtained by dividing the gradient functional composite prepared according to Example 1 of the present invention into the respective layers.
14 to 23 are graphs showing the XRD pattern analysis results obtained by dividing the gradient functional composite prepared according to Example 1 of the present invention into individual layers.
24 to 38 are scanning electron microscope (SEM) images obtained by dividing the gradient functional composite prepared according to Example 1 of the present invention into individual layers.
FIGS. 39 to 43 are graphs showing results of energy dispersive X-ray spectroscopy (EDS) analysis in which the gradient functional composite prepared according to Example 1 of the present invention is divided into individual layers.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Like parts are designated with like reference numerals throughout the specification.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a cross-sectional view showing an aluminum-titanium hetero-gradient functional composite according to an embodiment of the present invention. The aluminum-titanium hetero-gradient functional composite 100 according to one embodiment of the present invention includes a surface layer 130 made of titanium powder; A support layer 110 made of aluminum powder; And a mixed material inclined layer 120 composed of a plurality of mixed layers 125 in which aluminum powder and titanium powder are mixed between the surface layer 130 and the support layer 110,

The different material inclined layer 120 is formed such that the content of titanium decreases as each mixed layer 125 is disposed in the direction of the support layer 110 from the surface layer 130. In the mixed layer 125, (125) is greater in content of titanium than the mixed layer (125) adjacent to the support layer (110) direction.

For example, the dissimilar material inclined layer may include a mixed layer A of any one of the plurality of mixed layers and a mixed layer B that is in contact with the mixed layer A and located farther from the surface layer than the mixed layer A, The content may be more than the content of the titanium powder in the mixed layer B.

Since the heterogeneously graded composite material 100 according to the present invention is manufactured by mixing aluminum powder (2.7 g / cm 3) having lower density than titanium powder (4.506 g / cm 3), it is light compared to a material composed of only titanium, Can be used in fields requiring low weight.

In addition, not only lightweight properties but also excellent hardness and corrosion resistance are provided on the surface of titanium powder only, so that structural materials requiring reliability against corrosion are relatively inexpensive, workability is excellent, and excellent strength and corrosion resistance are exhibited It can be used in various fields.

In one embodiment of the present invention, the diameter of the aluminum powder and the titanium powder may be from 1 mu m to 300 mu m.

In one embodiment of the present invention, the diameters of the aluminum powder and the titanium powder may be the same or may be different.

The aluminum powder may be a 1000 series of pure aluminum powder that is commonly used and the aluminum powder may be selected from the group consisting of Mn, Si, Cu, Mg, Sn, Aluminum alloy powder containing at least one metal selected from the group consisting of aluminum alloy powders.

The aluminum alloy powder may be a known wrought alloy or a cast alloy. Examples of such aluminum alloy powder include Al-Mn series such as 3003, 3004 or 3014, Al-Mg-based alloys such as Al2O3 and Al2O3-4043, Al-Cu alloys such as 2017 and 2024 known as duralumin, Al-Mg alloys such as 5052 and 5083, Al-Mg-Si alloys such as 6061-T6, 6063 or 6N01, Al-Zn-Mg system and Al-Si-Cu-Mg system aluminum alloy such as 7075 can be exemplified.

It is preferable that the aluminum has an average particle diameter of 1 to 100 탆. If the average particle diameter is less than 1 탆, excessive alloying with the titanium powder may be caused. If the average particle diameter is less than 1 탆, The porosity becomes too high and it is difficult to induce the composite with titanium powder.

The titanium powder may be titanium which is commonly used. Preferably, the titanium powder may be selected from the group consisting of Grade 1, Grade 2, Grade 3, and Grade 4.

The titanium powder may be at least one selected from the group consisting of vanadium (V), molybdenum (Mo), zirconium (Zr), aluminum (Al), iron (Fe), nickel (Ni), cobalt (Co) , Neodymium (Nb), and combinations thereof. The titanium alloy powder may be a titanium alloy powder or a titanium alloy powder.

The titanium powder preferably has an average particle diameter of 1 to 300 탆. If the average particle diameter is less than 1 탆, excessive alloying with aluminum powder or aluminum alloy powder may occur, If the particle diameter exceeds 300 탆, the porosity becomes too high, and it is difficult to induce the composite with aluminum powder or aluminum alloy powder.

The content of the aluminum powder and the titanium powder contained in the mixed layer 125 of the heterogeneous gradient functional composite 100 of the present invention is different for each layer and the composition ratio of the aluminum powder and the titanium powder So that changes in the physical properties between aluminum and titanium are alleviated, so that it is not only resistant to mechanical impact and thermal shock but also can improve thermal shock characteristics and thermal fatigue characteristics.

The difference in the titanium powder content between any one of the plurality of mixed layers 125 and the adjacent mixed layers may be 10 to 30% by volume.

The aluminum powder and the titanium powder are in a correlation where the sum of the volume% value of the titanium powder and the aluminum powder is 100 volume%, and the volume ratio of the aluminum powder is increased Since it is obvious that it decreases or increases at the same rate, the difference value of the content is described based on the titanium powder content.

For example, the dissimilar material inclined layer includes a mixed layer C of any of the plurality of mixed layers 125 and a mixed layer D adjacent to the mixed layer C, and the volume percentage of the titanium powder of the mixed layer C with respect to the total volume of the mixed layer C, And the volume percentage of the titanium powder of the mixed layer D with respect to the total volume of the mixed layer D may be 10 to 30% by volume.

In the heterogeneously inclined composite material 100 of the present invention, the two mixed layers located on the symmetrical layer based on the mixed layer located at the center of the plurality of mixed layers 125 are symmetric in terms of the difference in the titanium powder content between adjacent layers .

For example, in a different material inclined layer 120 including an odd number of mixed layers, a center positioned layer is referred to as a center layer, one mixed layer E, a mixed layer adjacent to the mixed layer E as F, When the layers symmetrical with respect to the reference are E 'and F', respectively, the difference value of the titanium content of the mixed layer E and F may be the same as the difference value of the titanium content of E 'and F'.

If the titanium content does not satisfy the above range, the adhesion between the surface layer 130, the mixed layer 125, and the support layer 110 is not good, and delamination may occur.

In the plurality of mixed layers 125, the aluminum powder and the titanium powder can be variously formed according to their composition ratios, and the composite material can be manufactured using the aluminum powder and the titanium powder.

For example, it can be designed to contain a high content of titanium in the outside requiring strong hardness, and the inside can simultaneously realize excellent mechanical characteristics, corrosion resistance and light weight by increasing the content of aluminum or aluminum alloy having relatively high toughness have.

The thickness of the heterogeneous gradient functional composite material 100 may be controlled according to the number of the mixed layers to be stacked. Preferably, the thickness of the surface layer 130 may be less than the thickness of the support layer 110, or may be the same as the thickness of the support layer 110, in order to use less expensive titanium powder.

The heterogeneously inclined composite material 100 may be combined in one direction such as a layer 110 made of titanium powder, a gradient material 120 made of different materials, a layer 110 made of aluminum powder, A layer 130 made of powder - a different material inclined layer 120 - a layer 110 made of aluminum powder - a different material inclined layer 120 - a layer 130 made of titanium powder But is not limited thereto.

Each of the powder materials forming each layer constituting the heterogeneous gradient functional composite material 100 according to the present invention can be formed by sintering using a spark plasma sintering (SPS) process. Specifically, the aluminum powder and the titanium powder can be formed into respective layers having respective functions in one composite by laminating the respective powders and then sintering.

Hereinafter, a method of manufacturing the heterogeneously gradient functional composite material 100 will be described in detail.

The method for manufacturing an aluminum-titanium heterogeneous gradient functional composite material 100 according to an embodiment of the present invention includes the steps of: providing a support layer 110 made of aluminum powder; forming an aluminum powder and titanium powder on the support layer 110 Stacking a different material inclined layer 120 composed of a plurality of mixed layers 125; stacking a surface layer 130 made of titanium powder on the different material inclined layer 120; Wherein the different material inclined layer 120 is formed such that each of the mixed layers 125 is bonded to the surface layer 130 by a sputter plasma sintering process, The content of titanium is decreased as it is disposed in the direction of the support layer 110 and the content of titanium is higher than that of the mixed layer 125 in which one of the plurality of mixed layers 125 is adjacent to the direction of the support layer 110 It features many.

The step of joining using the spark plasma sintering process may be performed at a pressure of 30 to 200 MPa, at a temperature of 400 to 600 DEG C, and at a holding time of 5 to 10 minutes.

In this step, spark plasma sintering, which is used for composite of titanium powder and aluminum powder, is a method of sintering by applying a DC pulse current in a direction parallel to the pressing direction while pressing powder or plate material in one axis, Is a sintering method in which high energy of a plasma generated instantaneously by applying a pressure, a low voltage and a large current to the plasma is applied to electric field diffusion, thermal diffusion and the like. This spark plasma sintering can lower the sintering temperature by about 200 to 500 DEG C and can complete the sintering in a short time including the temperature rise and the holding time as compared with the method of manufacturing the composite material by the conventional casting method, It is easy to handle, and the operation cost is low.

Unlike the hybridization process using the conventional casting method (melting method), the present invention uses a low-energy solid-phase powder metallurgy process for producing a heterogeneously graded composite material by sintering a powdery starting material through spark plasma sintering It is possible to manufacture a composite material of heterogeneous inclined function with a short time and a high density and a mechanical strength and a corrosion resistance equivalent to those of titanium, as well as a lightweight, heterogeneous inclined composite material excellent in workability.

FIG. 2 is a conceptual diagram schematically showing a spark plasma sintering apparatus according to an embodiment of the present invention, and FIG. 3 is a conceptual diagram schematically showing a spark plasma sintering process according to an embodiment of the present invention.

2, the spark plasma sintering process includes a vacuum chamber 201, a die assembly 202, a current supply device 203, a pressure device 204, A device 205, a temperature and pressure measuring device 206, an electrode 207, a mixed powder, and the like.

Specifically, a composite powder in which the aluminum powder and the titanium powder are mixed is charged into a carbon mold, and the carbon mold is set in the sintering die 302 in the vacuum chamber 201. The set vacuum chamber 201 is depressurized by the pressure reducing device 204 by the pressure reducing device 204 and a current is applied to the upper and lower punch electrodes 207 through the DC power supply device 203, My temperature is raised. The control of the constant pressure and the temperature in the chamber controls the temperature measuring instrument, the pressure reducing device, the pressure applying part 204, the DC power supply part 203, and the like in the control part 205 to produce a certain sintered body. After sintering for a predetermined time, cooling is performed in the chamber 201 by using a cooling device argon or nitrogen gas.

Referring to FIG. 3, the spark plasma and sintering process will be described. A pulse current 303 is supplied along the mixed powder 301, thereby generating a spark plasma discharge phenomenon 305 occurring in a short time. The titanium powder and the aluminum alloy powder 301 contained in the mixed powder may be combined by the joule heat 304 formed in the mixed powder to form a dense composite material.

It is preferable that the sintering process is performed at a temperature below the melting point of aluminum, for example, at a temperature of 400 to 600 DEG C for 30 to 200 MPa for 5 to 10 minutes.

If the sintering temperature is lower than 400 ° C, it may be difficult to produce a structure having a good bonding strength between the Ti and Al interfaces. If the sintering temperature is higher than 600 ° C, it is difficult to maintain the shape due to melting of the aluminum powder, The mechanical properties may be deteriorated.

When the spark plasma sintering is used as described above, the temperature and time at which mutual diffusion of the constituent elements of aluminum and titanium or aluminum alloy is not sufficient, the range of the interfacial product is very small and the range of compositional change is extremely limited, It is possible to maintain the inherent characteristics.

Concretely, if it is not carried out under the above conditions, the density becomes extremely low under a condition of too low a pressure, internal residual stress is accumulated at a too high pressure, and cracks are generated after manufacturing . Further, when sintering is maintained for a long time, problems such as lowering hardness may occur due to grain growth or the like.

Particularly, when the sintering temperature is lower than 400 ° C, it may be difficult to produce a structure having a good bonding strength between the Ti and Al interfaces. When the sintering temperature exceeds 600 ° C, it is difficult to maintain the shape due to melting of the Al powder. The mechanical properties may be deteriorated.

On the other hand, in the case of a general alloy, an intermetallic compound may be formed in a liquid phase in which the powder form disappears by sintering the metal powder at a high temperature to form an aggregate of the alloy in which the powder form disappeared. These intermetallic compounds often have very high strength, but may result in lack of toughness due to excessive alloying.

In addition, due to the difference in melting point between the aluminum powder and the titanium powder, when the aluminum having a lower melting point is first liquefied, it may be difficult to homogeneously disperse such as segregation due to the migration of the liquid aluminum.

Meanwhile, the aluminum-titanium hetero-gradient functional composite 100 according to the present invention is characterized in that the aluminum-titanium alloy is prevented from being excessively alloyed by controlling the sintering conditions and is made into a bulk phase in which the aluminum-titanium alloy is homogeneously mixed in the form of powder . Especially, in the sintering process, the spark plasma sintering process is performed on the solid aluminum powder and the titanium powder to generate an intermetallic compound by generating a very large energy for a very short time. The production of an intermetallic compound at a low sintering temperature as in the production method of the present invention can solve the problem of toughness occurring in a general alloy process by a very unique technique.

When the spark plasma sintering is used as described above, the temperature and time for the mutual diffusion of the component elements between the aluminum powder and the titanium powder are insufficient, the range of the interfacial product is very small and the range of compositional change is extremely limited. Can be maintained.

In addition, by using the spark plasma sintering process as described above, it is possible to manufacture the heteroepitaxial composite material at a temperature lower than the conventional synthesis temperature and in a short time, thereby reducing the manufacturing cost.

According to the method for producing an aluminum-titanium heteroepitaxy composite material according to the present invention, aluminum powder and titanium powder, which are starting materials, are rapidly densified and compounded without a composition change by using a spark plasma sintering process in a complexing step, It is possible to produce an aluminum-titanium heteroepitaxial composite material having excellent physical properties including all of the advantages such as light weight, excellent corrosion resistance, processability and mechanical properties.

In general, in a method of bonding aluminum to titanium, a surface layer 130 made of titanium powder; A support layer 110 made of aluminum powder; And a heterogeneous material inclined layer 120 composed of a plurality of mixed layers 125 in which aluminum powder and titanium powder are mixed between the surface layer 130 and the support layer 110, The content of titanium decreases as each of the mixed layers 125 is disposed in the direction of the support layer 110 from the surface layer 130 and the mixed layer 125 of any of the plurality of mixed layers decreases in the direction of the support layer 110, Wherein the bonding is performed at a pressure of 30 to 200 MPa, a temperature of 400 to 600 DEG C and a holding time of 5 to 10 minutes using a spark plasma sintering process .

In one embodiment of the present invention, the mixed powder of each of the mixed layers constituting the inclined layer 120 is mixed using a ball mill process, ultrasonic dispersion, blending, tubular mixing or the like However, it is preferable to use a ball mill process.

In this step, a milling method for pulverizing and mixing the aluminum powder and the titanium powder or the aluminum alloy powder is such that the raw powder is uniformly pulverized and mixed to form a composite material through a spark plasma sintering process at a later stage The specific method is not particularly limited as long as it can.

For example, this step may be performed through a mechanical mixing process by milling using ball milling, planetary milling, or attrition milling.

For example, in order to carry out the above process by means of the ball milling method to prepare the starting material, it can be configured to be carried out at 100 to 500 rpm for 6 to 24 hours to prepare a mixed powder which is pulverized and mixed in a uniform size And more preferably 200 rpm for 10 to 14 hours.

The mixed powder can control physical properties such as specific gravity, elongation, tensile strength, and hardness by controlling the volume ratio of the titanium powder and the aluminum powder.

In one embodiment of the present invention, due to the large surface area of the aluminum powder and the titanium powder particles, more bonding regions or boundaries can be formed between the dissimilar materials, The bonds that can be formed between the materials by the atoms are further increased, so that a more rigid composite material can be produced.

Since the heterogeneous inclined composite material according to the present invention has both aluminum and titanium characteristics, it exhibits excellent strength and mechanical properties as well as lightweight properties, and thus can be applied to machines, automobiles, trains, ships, and aerospace .

In one embodiment of the present invention, the heterogeneously graded functional composite material 100 may have a Vickers hardness of 120 to 460 Hv.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are for illustrative purpose only and that the scope of the present invention is not limited to these embodiments.

[ Manufacturing example  1: Manufacture of aluminum-titanium heteroepitaxial composite material]

< Example  1>

Titanium (SUS316L) powder and aluminum powder were used to prepare surface layers and support layers, respectively. Then, the aluminum powder and the titanium powder were mixed in the composition shown in Table 1 below and mixed using a ball mill for 6 hours, respectively. After mixing, a carbon layer of 10 mm in diameter was sequentially laminated on the support layer as the lowest layer in the order described in Table 1 below. Then, a spark plasma sintering process was performed at 200 MPa and 600 ° C for 5 minutes to produce an aluminum-magnesium composite material. At this time, the temperature raising rate was 100 deg. C per minute. The diameter of the cylindrical heterogeneous gradient functional composite material was 15 mm and the thickness was 20 mm.

The difference in the titanium content of each layer of the produced heterogeneous functional composite material is 20% by volume, 30% by volume, 30% by volume and 20% by volume from the surface layer, respectively, and the range of the difference value is from 10% by volume to 30% by volume. The two layers (20 vol%, 80 vol%), which are adjacent to each other and symmetrical to each other with respect to the center layer (50 vol%), were decreased by 30 vol% in the direction of the surface layer and increased by 30 vol% And the difference value between the support layer and the surface layer is also 20% by volume, respectively, and the difference value is symmetric.

Al / Ti (vol.%) material Density (g / cm3) Volume (cm &lt; 3 & Weight (g) Al / Ti (100 / -) Al (75 탆) 2.700 - - Al / Ti (80/20) Al (75 탆) 2.700 52.27 141.12 Ti (150 탆) 4.506 13.07 58.88 Total 3.061 65.33 200.00 Al / Ti (50/50) Al (75 탆) 2.700 13.87 37.45 Ti (150 탆) 4.506 13.87 62.50 Total 3.603 27.74 99.95 Al / Ti (20/80) Al (75 탆) 2.700 9.65 26.06 Ti (150 탆) 4.506 38.60 173.94 Total 4.145 48.25 200.00 Al / Ti (- / 100) Ti (150 탆) 4.506 - -

< Comparative Example  1: Preparation of aluminum-titanium hetero-composite material &gt;

An aluminum-titanium hetero-composite was produced in the same manner as in Example 1, except that a different material inclined layer was not provided between the surface layer and the support layer.

< Comparative Example  2: Preparation of aluminum-titanium hetero-composite material &gt;

Titanium powder and aluminum powder were mixed at a composition ratio of 50:50 by volume and mixed using a ball mill for 6 hours. After mixing, the spark plasma sintering process was performed at 200 MPa and 600 ° C for 5 minutes to produce an aluminum-magnesium composite material. At this time, the temperature raising rate was 100 deg. C per minute. The diameter of the aluminum-titanium hybrid composite produced was 15 mm and the thickness was 20 mm.

[ Experimental Example  One: Vickers  Measurement of Hardness (Vickers Hardness)

The Vickers hardness of the composite material of Example 1 and Comparative Example 1 was measured and is shown in Table 2 below. Specifically, one surface of each composite material was measured three times each, and the average value thereof was shown.

Classification (% by volume) Vickers hardness (HV) Example 1 Al Ti 1 time Episode 2 3rd time 4 times 100 0 20.9 21.8 19.0 18.3 80 20 58.3 60.5 61.3 59.7 50 50 324.5 317.9 329.3 330.7 20 80 369.5 370.2 362.5 358.2 0 100 157.6 160.3 149.2 152.4 all 315.3 314.9 311.5 323.9 Comparative Example 1 100 0 18.5 21.3 20.9 19.2 0 100 140.5 138.2 142.3 142.6 all 79.5 80.5 81.2 82.4 Comparative Example 2 50 50 310.5 324.8 309.8 330.6

With reference to Table 2, it was confirmed that the Vickers hardness value of the heterogeneously graded composite material of Example 1 was greatly increased compared to the Vickers hardness value of the composite material of Comparative Example 1. [

Particularly, since the Vickers hardness average value of the support layer composed of only the aluminum powder is about 20 Hv, the Vickers hardness average value of the mixed layers constituting the inclined layer of the different material greatly increases to about 58 Hv to 369 Hv, It was found that the heterogeneous gradient functional composite material can exhibit more excellent mechanical properties by providing the inclined layer.

Thus, it was confirmed that the heterogeneously tapered composite material of Example 1 according to the present invention exhibited superior corrosion resistance and strength as well as superior mechanical properties as compared with the composite material of Comparative Example 1. [

[ Experimental Example  2: Crystallographic characterization of inclined composite materials HV ( OM ), XRD ]

HV (OM) and XRD analysis of the gradient functional composite prepared according to Example 1 was performed. The vickers hardness of the composite materials HV (OM) was measured for 5 seconds using a HM-101 Vickers hardness tester manufactured by Mitutoyo of Japan according to JIS B 7725, ISO 6507-2 under a load of 0.3 kg , And X-ray diffraction (XRD) patterns were measured using an X-ray diffractometer (trade name Ultima IV) manufactured by Rigaku Corporation, Japan. The X-ray diffractometer utilizes a linear detector (D / tex ultra) with a Cu Kα radiation source (λ = 1.5148 Å, 40 kV, 40 mA) in the 2θ range from 20 to 80 °.

Figs. 4 to 13 are photographs showing the HV (OM) measurement results of the respective layers of the gradient functional composite prepared according to Example 1. Fig. Figs. 4 to 8 are magnifications of 10 magnifications, and Figs. 9 to 13 are magnifications of magnification of 40 magnifications. The contents of aluminum and titanium (Al / Ti (vol%)) are shown in Fig. 4 (100 / -), Fig. 5 (80/20), Fig. 6 (50/50) - / 100), and FIGS. 9 (100 / -), 10 (80/20), 11 (50/50), 12 (20/80) and 13 (- / 100). According to Figs. 4 to 13, it was confirmed that the support layer and the surface layer show a monocrystalline structure of aluminum and titanium in general, but the inclined layer shows a crystal structure of various shapes varying in the size of the boundary depending on the composition.

These crystallographic characteristics can also be seen from the XRD results of FIGS. 14-23. Figs. 14 to 18 show the mixed powder (Ti + Al) before the SPS process, and 19 to 23 show the XRD analysis results of the composite material obtained after the SPS process. The contents of aluminum and titanium (Al / Ti (volume%)) are shown in Figs. 14 (100 / -), 15 (80/20), 16 (50/50), 17 (20/80) - / 100), and FIGS. 19 (100 / -), 20 (80/20), 21 (50/50), 22 (20/80) and 23 (- / 100).

In addition, the mixed powder shows a single phase, but a small amount of intermetallic compounds (Al ₃ Ti, Al ₅ Ti ₂ , Al ₁₁ Ti ₅ ) are formed besides the Al and Ti phases after the spark plasma sintering process (SPS) .

[ Experimental Example  3: Analysis of Microstructure of Graded Composite Material]

24 to 38 are SEM (scanning electron microscope) images obtained by dividing the gradient functional composite prepared according to Example 1 into the respective layers. Figs. 24 to 28 are 100 mu m, Figs. 29 to 33 are 50 mu m, and Figs. 34 to 38 are enlarged in 20 mu m units.

The contents of aluminum and titanium (Al / Ti (volume%)) are shown in Figs. 24 (100 / -), 25 (80/20), 26 (50/50), 27 (20/80) - / 100), and FIG. 29 (100 / -), 30 (80/20), 31 (50/50), 32 (20/80) 100 / -, 35 (80/20), 36 (50/50), 37 (20/80), and 38 (- / 100).

39 to 43 show the results of energy dispersive x-ray spectroscopy (EDS). The contents of aluminum and titanium (Al / Ti (volume%)) are shown in FIG. 39 (100 / -), 40 (80/20), 41 (50/50), 42 (20/80) - / 100).

The SEM image was measured using a device (model name VEGA 2 LSU) of TESCAN, and the EDS was measured using a device (model name S-2400) manufactured by HITACHI, Japan. The gradient functional composite prepared according to Example 1 was etched into an aqueous 5% NaOH solution to conduct an EDS analysis inside the electron microscope.

24 to 38, the support layer and the surface layer of the gradient functional composite produced in Example 1 generally show a single microstructure of aluminum and titanium, but in the case of the sloped layer, various shapes of boundary microstructures Of the total population. In addition, it can be seen that microstructures can be controlled according to the composition of the constituent material, which means that the physical properties of the inclined layer can be controlled as a result.

In FIGS. 24 to 38, only one component of each of the support layer and the surface layer was detected, and in the case of the sloped layer, a peak value similar to the compositional content of the constituent material was shown.

[ Experimental Example  4: Reliability Experiment]

Corrosion resistance Moisture resistance Abrasion resistance
(% Wear rate) Example 1 PASS PASS 0.1% Comparative Example 1 Partial whiteness of AL layer occurred
TI layer PASS AL layer PASS
TI layer PASS AL layer 3%
TI layer 0.1% Comparative Example 2 PASS PASS 0.08%

The corrosion and moisture resistance tests were conducted by spraying a salt spray (KS D 9502: 2009) for 12 hours using a salt spray tester (ITABASHI_SQ-1000-CA) .

The abrasion resistance was measured by performing a wear test on a ball-on-disk type tribometer (JLTB060, J & L Tech) under the conditions of a load of 30 N, a time of 1800 sec, and a WC ball. The lower the wear rate, the better the abrasion resistance.

As a result of the experiment, it was confirmed that the antifriction and the moisture resistance of the gradient functional composite prepared according to Example 1 of the present invention was excellent. In the friction test, the wear rate was measured to be about 0.1% similar to Comparative Example 2, And it was confirmed that it was improved as compared with Comparative Example 1.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

100: inclined function complex
110: titanium layer
120: bonding layer
125: mixed layer
130: Aluminum layer
200: Spark plasma sintering apparatus
201: Vacuum chamber
202: Die assembly
203: Current supply
204: Pressurizing device
205: Control device
206: Temperature and pressure measuring device
207: Electrode
300: Spark plasma sintering process
301: mixed powder
302: Die
303: Pulse current
304: jelly
305: Discharge

Claims (8)

A surface layer composed of titanium powder;
A support layer made of aluminum powder; And
And a mixed material inclined layer composed of a plurality of mixed layers in which aluminum powder and titanium powder are mixed between the surface layer and the support layer,
Wherein the content of titanium is decreased as each mixed layer is disposed in the direction of the support layer from the surface layer, and the content of titanium is greater than that of the mixed layer adjacent to the direction of the support layer
Aluminum - titanium heterogeneous inclined composite material. The method according to claim 1,
Wherein the aluminum powder is an aluminum alloy powder further comprising any metal selected from the group consisting of manganese (Mn), silicon (Si), copper (Cu), magnesium (Mg), tin (Sn) Aluminum-titanium hetero-gradient composite. The method according to claim 1,
The titanium powder may be at least one selected from the group consisting of vanadium (V), molybdenum (Mo), zirconium (Zr), aluminum (Al), iron (Fe), nickel (Ni), cobalt (Co), silicon Titanium (Nb), and combinations thereof. &Lt; Desc / Clms Page number 24 &gt; The aluminum-titanium heteroepitaxial composite material is a titanium alloy powder further containing any one metal selected from the group consisting of titanium, The method according to claim 1,
Wherein the difference in the titanium powder content between any one of the plurality of mixed layers and the adjacent mixed layers is 10 to 30% by volume. The method according to claim 1,
Wherein the two mixed layers located on the symmetrical layer based on the mixed layer located at the center of the plurality of mixed layers are symmetrical in the difference in the content of titanium powder with the adjacent layer. The method according to claim 1,
Wherein the Vickers hardness of the aluminum-titanium heterogeneously gradient functional composite material is 120 to 460 Hv. Providing a support layer of aluminum powder,
Laminating a heterogeneous material inclined layer composed of a plurality of mixed layers in which aluminum powder and titanium powder are mixed on the support layer,
Laminating a surface layer made of titanium powder on the heterogeneous material inclined layer; and
And sintering the stacked support layer, the different material inclined layer and the surface layer using a spark plasma sintering process,
Wherein the content of titanium is decreased as each mixed layer is disposed in the direction of the support layer from the surface layer, and the content of titanium is greater than that of the mixed layer adjacent to the direction of the support layer
A method for manufacturing an aluminum - titanium heteroepitaxial composite material. 8. The method of claim 7,
Wherein the step of sintering using the spark plasma sintering process is performed under the conditions of a pressure of 30 to 200 MPa, a temperature of 400 to 600 DEG C and a holding time of 5 to 10 minutes.

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