KR102001397B1 - Manufacturing Method of Aluminum-Silicon Carbide Using By-product of Cutting Process - Google Patents

Abstract

The present invention relates to a process for producing aluminum-silicon carbide using cutting-off by-products which can produce aluminum-silicon carbide, which is a high strength composite material, at low cost by using cutting fragments (scrap) of aluminum extruded material and silicon carbide of waste silicon sludge will be. (A) cutting, washing and drying a first raw material containing aluminum; (b) preparing an aluminum-silicon carbide composite powder by mixing the first raw material and a second raw material containing silicon carbide (SiC) and then pulverizing the mixture; And (c) compressing and sintering the aluminum-silicon carbide composite powder to produce a compression-molded body.

Description

Technical Field [0001] The present invention relates to an aluminum-silicon carbide manufacturing method using a by-

The present invention relates to a method of manufacturing aluminum-silicon carbide using a by-product of cutting, and more particularly, to a method of manufacturing aluminum-silicon carbide using a by- To a process for producing aluminum-silicon carbide using a by-product of a cutting process capable of producing silicon carbide.

Composite materials are attracting attention as an alternative to overcome the limitations of individual materials such as metals, ceramics, and chemical materials. According to the press release of the Korea Textile Industry Association, issued in October 2012, Korea's global market share of the carbon materials market is around 2%. Based on this, the domestic market size of multifunctional carbon composite materials is estimated to reach USD 41.5 billion To $ 156.3 billion by 2020.

In addition, the automotive textile market is expected to grow sharply thanks to the strengthening of environmental regulations such as ELV (End Life Vehicle) of European Directive 2000/53 / CE, effective from January 2015. Accordingly, demand for global carbon fiber composites is projected to grow at an annual CAGR of more than 20% from 46,000 tonnes to 96,000 tonnes in 2015. Nevertheless, demand is insignificant. However, new demand for wind turbine blades and automotive structural components is expected to grow rapidly in existing demand such as sports leisure goods and aircraft. Especially in Europe, BMW introduced the new i3 / 8 series of carbon fiber composite materials to the body-in-white market this year, and it is expected that demand for automobiles will increase in the future due to the market reaction. In addition, second-tier companies such as Saudi Arabia and Turkey are expected to increase their new production capacity by 33,000 tons in 2015, and supply to the world is expected to reach 125,000 tons. Overcapacity is expected to exceed 29,000 tons.

In addition, demand for high-performance, high value-added non-ferrous metals such as aluminum, magnesium, and titanium is increasing in light metal materials. Growth of production technology will continue with the enforcement of environmental regulations, and will grow at an annual average of 5.4% do. However, the weight of the light metal material is lower than that of iron, and the cost is high in the processing.

In order to solve the above-mentioned problems, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a process for producing aluminum-silicon carbide, which is a composite material of high strength at a low cost by using cutting scrap of aluminum extruded material and silicon carbide of waste silicon sludge. - a method for producing silicon carbide.

In order to solve the above-mentioned problems, the present invention according to a first aspect is characterized in that (a) cutting, washing and drying a first raw material containing aluminum; (b) preparing an aluminum-silicon carbide composite powder by mixing the first raw material and a second raw material containing silicon carbide (SiC) and then pulverizing the mixture; And (c) compressing and sintering the aluminum-silicon carbide composite powder to produce a compression-molded body.

The first raw material may include a cutting chip, a can, a plate or a slab.

The cutting chip may be a by-product of the aluminum cutting process.

The silicon carbide may be derived from a silicon ingot cutting process by-product of a solar panel or a semiconductor.

The silicon carbide may be prepared by acid treatment of the silicon ingot cutting process by-products and then ultrasonic spraying.

In the step (a), the cut raw material may be mixed with water and a cleaning agent, followed by washing using a centrifugal separator, followed by drying using a vacuum dryer.

The step (b) may be carried out using a planetary miller at 100 to 1000 rpm for 5 to 60 minutes, and the content of the second raw material may be 1 to 10% by weight relative to the first raw material.

The step (c) comprises: (i) inserting an aluminum-silicon carbide composite powder into a chamber; (ii) first heating the chamber to a temperature of 350 to 500 ° C at a rate of 2 to 10 ° C / min; (iii) decompressing the chamber to remove gas inside the formed body; (iv) secondarily heating the chamber to 520 to 900 ° C at a rate of 5 to 15 ° C / min; And (v) pressurizing the chamber at a pressure of 100 to 200 MPa for 10 to 60 minutes.

The present invention according to the second aspect also provides aluminum-silicon carbide produced by the method.

The method for producing aluminum-silicon carbide according to the present invention can produce aluminum-silicon carbide by using by-products of aluminum cutting process and by-products of semiconductor processing, so that aluminum, which is used as waste material or used as de- Aluminum that depends on import can not only reduce the shape of cow but also can produce composite material with high added value at low cost.

1 is a photograph of a raw material according to an embodiment of the present invention, wherein (a) is an aluminum cutting chip, and (b) is a photograph of silicon carbide.
2 shows a cleaning process of an aluminum cutting chip according to an embodiment of the present invention, which comprises (a) preparing water at a certain temperature, (b) preparing a cleaning agent, and (c) photographing a mixture of water, to be.
FIG. 3 is a photograph of a detachable cleaner according to an embodiment of the present invention.
4 is a photograph of a vacuum dryer according to an embodiment of the present invention.
FIG. 5 is a photograph showing a comparison of aluminum cutting chips before and after cleaning according to an embodiment of the present invention. FIG.
6 is a photograph of a planetary mirror according to an embodiment of the present invention.
FIG. 7 is a photograph showing a pulverizing process using a planetary miller according to an embodiment of the present invention. FIG. 7 (a) shows the preparation of the raw material, (b) inserts the raw material and balls into each jar, d) the number of raw materials collected.
FIG. 8 is a photograph of an aluminum-silicon carbide composite powder according to an embodiment of the present invention. FIG. 8 (a) is an example in which pulverization does not occur well, and FIG.
FIG. 9 is a photograph of an aluminum-silicon carbide composite powder according to an embodiment of the present invention. FIG. 9 (a) is a photograph of an example in which pulverization failure and (b)
10 is a graph illustrating particle size analysis results according to an embodiment of the present invention.
11 is a photograph showing a manufacturing process of a test piece according to an embodiment of the present invention, wherein (a) is a process of mounting an aluminum-silicon carbide composite powder and (b) is a surface polishing process.
FIG. 12 shows the results of surface analysis of the aluminum-silicon carbide composite powder according to an embodiment of the present invention, wherein (a) shows a silicon carbide content of 10% by weight and a planetary mirror operating time of 5 minutes, (C) shows a silicon carbide content of 10% by weight and a planetary mirror operating time of 5 minutes, (d) shows a silicon-carbide content of 5% by weight and a planetary mirror operating time of 30 minutes, Fig. 2 is an enlarged view of the surface of the carbide composite powder.
13 is an EDX analysis image of an aluminum-silicon carbide composite powder according to an embodiment of the present invention.
14 shows X-ray mapping results of an aluminum-silicon carbide composite powder according to an embodiment of the present invention.
15 is a photograph of a cross section of an aluminum-silicon carbide composite powder according to an embodiment of the present invention.
16 is a photograph showing a mold (a) for compressing aluminum-silicon carbide composite powder and a sintering apparatus (b) for heating a living mold according to an embodiment of the present invention.
17 is a photograph of a sintered aluminum-silicon carbide composite powder at room temperature according to an embodiment of the present invention.
18 is a photograph of sintering the aluminum-silicon carbide composite powder according to an embodiment of the present invention at a high temperature.
FIG. 19 is a graph showing a change in temperature during sintering of an aluminum-silicon carbide composite powder according to an embodiment of the present invention. FIG.
20 is a photograph showing an extruded material manufactured using an aluminum-silicon carbide composite powder according to an embodiment of the present invention.
FIG. 21 is a photograph of the manufacturing process (a) and the extruded material (b) of the extruded product according to the embodiment of the present invention.
22 is a test result of the tensile strength and elongation of an extruded material according to an embodiment of the present invention.
23 is a test result of the thermal conductivity of the extruded material according to an embodiment of the present invention.
24 is a density test result of an extruded material according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Throughout the specification, when an element is referred to as "including " an element, it means that it can include other elements, not excluding other elements, unless specifically stated otherwise.

(A) cutting, washing and drying a first raw material containing aluminum; (b) preparing an aluminum-silicon carbide composite powder by mixing the first raw material and a second raw material containing silicon carbide (SiC) and then pulverizing the mixture; And (c) compressing and sintering the aluminum-silicon carbide composite powder to produce a compression-molded body.

In the present invention, the first raw material may include a cutting chip, a can, a plate material, or a grooved material. Aluminum recycling in the conventional extrusion process is mainly limited to the scrap generated in the initial primary process, which is the extrusion process of the round bar type base material, and is mostly used for the original circulation to the raw materials. However, cutting chips generated during cutting have limited use and have been used as low-cost deoxidizers in casting processes. In addition, when recycled as a raw material, it is disadvantageous in that the recovery rate is lowered due to occurrence of slag. Therefore, in the present invention, it is possible to supply the aluminum raw material at low cost by cutting and using cutting chips, cans, plate materials or slabs including aluminum, and it is possible to increase the recovery rate of aluminum and minimize the manufacturing cost.

Silicon carbide may also be a by-product of the silicon ingot cutting process in solar panels or semiconductors. The waste silicon sludge generated in the silicon ingot cutting process of solar panels and semiconductors is in the stage of establishing to some extent by the development of the separation process technology domestically. However, since the particles of silicon sludge are very small, their use as raw materials is limited. However, as in the present invention, since small particles can be directly used for manufacturing aluminum-silicon carbide, it is possible to produce a composite material at a low cost.

In addition, silicon carbide can be produced without any limitation as long as it can separate silicon carbide from the by-product of the silicon ingot cutting process. Preferably, the silicon carbide can be produced by acid treatment of the silicon ingot cutting process and then ultrasonic spraying .

In the step (a) of the present invention, the cut raw material is mixed with water and a cleaning agent, followed by washing using a centrifugal separator and drying using a vacuum dryer. In the aluminum extrusion process through heating, extrusion, cooling, calibrating and cutting processes, ribbon-like debris may be generated in the cutting process. In addition, as described above, it is also possible to use recycled products such as cans, plates, or sheets, or debris generated during recycling. The first raw material collected as described above is cut to an appropriate size and washed. The washing solution used herein is not particularly limited as long as it is a solution capable of removing contamination adhering to the surface of the first raw material. Preferably, Can be used. It is preferable that the detergent is selected in consideration of contamination degree of the first raw material, manufacturing cost, and the like.

As described above, the first raw material mixed with the water and the cleaning agent is put into the centrifugal separator to be cleaned. The centrifugal type scrubber is a device for cleaning a raw material in a cylindrical shape by rotating cylindrical cleaning means. The centrifugal type scrubber can be used by adjusting the rotation speed and the cleaning time according to the contamination degree of the first raw material and the type of the cleaning agent. At a speed of 10 to 50 minutes, more preferably at a speed of 600 to 800 rpm for 20 to 40 minutes. When the centrifugal separator is rotated at a speed less than 500 rpm or less than 10 minutes, the cleaning is not completed, so that it may be difficult to grind in the subsequent grinding process, impurities may be mixed, and when cleaning is performed at 900 rpm or more than 50 minutes, May be in contact with each other and may be pulverized, thereby decreasing efficiency in drying. It is also possible to remove the detergent component by washing with water 2 to 10 times without the detergent after the washing is completed.

The first raw material washed by the above-described method is heated by a vacuum dryer to prevent the oxidation of residual water inside. At this time, a vacuum dryer capable of drying the first raw material may be used without limitation, and may be dried for a suitable time according to the content of moisture contained therein.

In the present invention, the step (b) may be performed using a planetary miller at 100 to 1000 rpm for 5 to 60 minutes, and the weight ratio of the second raw material to 100 parts by weight of the first raw material may be 1 to 10 parts by weight. In the step (b), aluminum and silicon carbide are mixed and pulverized. Preferably, the step (b) is performed using a planetary mirror.

The planetary miller is a type of rotary grinder that crushes raw materials introduced into a cylinder by the motion of a ball inside a rotating cylinder Jar. When the cylinder rotates, the inner balls irregularly come into contact with the raw material, . During the grinding process, the powder of each material is repeatedly subjected to micro-fracture and cold welding between the balls, and finally mixed to the atomic scale to complete the powder having a specific microstructure.

The factors that determine the efficiency of the planetary mirror are as follows.

비율 Ratio of milling ball to sample: When the volume of loaded balls and powder is larger than the volume of the container, the dropping distance of the ball is decreased and the impact energy is decreased. Productivity can be lowered. Therefore, in the present invention, it is preferable that the mixture of the ball and the raw material is charged in an amount of 20 to 50% by volume of the inner volume of the cylinder.

㉯ Size and volume of milling balls: Milling balls used can be 5 ~ 20mm in diameter. When the size of milling balls is larger than 20mm, it is difficult to grind to the desired size due to the increase of particle size at the milling of raw material. The mass of the milling ball is reduced and the milling is not easy.

㉰ Material of milling balls and jars: The material of the milling balls and the container can be used without restrictions as long as the material is not mixed with the raw materials during the crushing of the internal raw materials, but preferably stainless steel, alumina or zirconium can be used have.

㉱ Milling speed and time: The planetary miller collides with the powder at the bottom of the barrel at the proper height due to the relationship between gravity and centrifugal force, and crushes the powder. Therefore, if the speed of rotation is slow, the ball can not rise along the wall of the container and only causes friction with the wall of the barrel. If the centrifugal force acting on the container wall is higher than the ball's gravity when the velocity is high, So that the powder can not be crushed. Accordingly, the rotational speed of the planetary mirror may be 200 to 800 rpm, preferably 400 to 600 rpm.

㉲ Milling atmosphere: The oil milling generates a lot of heat by the friction of the raw material wheat balls, and since the size of the pulverized particles is very small, oxidation reaction may occur due to reaction with oxygen in the air. Therefore, it is preferable to fill the inside of the cylinder Jar with an inert gas such as N ₂ , Ar or Ne or to keep it in a vacuum to prevent oxidation of the raw material.

In the step (c) of the present invention, the compression-molded body is manufactured by compressing and sintering the aluminum-silicon carbide composite powder, the method comprising the steps of: (i) inserting the aluminum-silicon carbide composite powder into the chamber; (ii) first heating the chamber to a temperature of 350 to 500 ° C at a rate of 2 to 10 ° C / min; (iii) decompressing the chamber to remove gas inside the formed body; (iv) secondarily heating the chamber to 520 to 900 ° C at a rate of 5 to 15 ° C / min; And (v) pressurizing the chamber at a pressure of 5 to 100 MPa for 10 to 60 minutes.

When the aluminum-silicon carbide composite powder is compression-molded at room temperature, the compactness of the formed body may be deteriorated. Therefore, it is preferable that the composite powder is heated to a high temperature and then compression molded to increase the compactness. In order to improve the denseness of the composite powder and to control the pores, it is preferable that the chamber is depressurized and held in a vacuum. In this case, since a commonly used booster press is mainly manufactured only for pressing the powder, it is preferable to manufacture a composite powder by installing a vacuum chamber and a heater as shown in FIG.

The heater can be freely selected if it is a heater capable of heating the chamber, and the chamber can be heated in two steps for convenience of gas removal and heating in the chamber (FIG. 19). The first heating is a step of heating the chamber to a temperature of 350 to 500 ° C, preferably 400 to 460 ° C at a rate of 2 to 10 ° C / min, preferably 5 to 9 ° C / min, There is no change in the silicon carbide composite powder, but the gas present inside the composite powder can be discharged.

The chamber, which is heated as described above, is subjected to a decompression step to remove the internal gas. The depressurization step is a step for removing harmful gas present in the aluminum-silicon carbide composite powder, and it is preferable to reduce the pressure to a pressure of 10 ^-3 to 10 ^-1 torr.

When the decompression step is completed, a step of second heating and sintering the chamber may be performed. The sintering is performed by heating the chamber at a temperature of 520 to 900 ° C, preferably 650 to 750 ° C at a rate of 5 to 15 ° C / min, preferably 8 to 13 ° C / min, For 60 to 120 minutes, and more preferably for 80 to 100 minutes. At this time, the aluminum-silicon carbide composite powder existing in the chamber is heated and sintered at a temperature of 500 to 650 ° C, preferably 550 to 600 ° C.

After the secondary heating step, the aluminum-silicon carbide primary molded body is produced, and the internal pores of the produced molded body are removed, the pores are reduced, and the pressing is performed at a high temperature to dense the structure. At this time, the chamber may be pressurized at a pressure of 5 to 100 MPa for 10 to 60 minutes, preferably at a pressure of 10 to 30 MPa for 20 to 40 minutes, more preferably at a pressure of 13 to 18 MPa for 20 to 40 minutes have. The higher the applied pressure, the more dense the structure can be formed. However, if the pressure is higher than 100 MPa, the manufacturing cost may be increased. If the pressure is lower than 5 MPa, the formation of the tissue may be incomplete.

The second aspect of the present invention also provides aluminum-silicon carbide produced by the above method.

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

Example 1: Preparation of aluminum-silicon carbide powder

Aluminum-silicon carbide powders were prepared using an aluminum cutting chip (Fig. 1 (a)) collected in the field development and Fixtea. 1500 g of the chips were mixed with 10 L of water at 75 to 80 ° C and 300 g of detergent (FIG. 2), and the mixture was put into a centrifugal washer (FIG. 3). The centrifugal washer was operated at a rotating speed of 700 rpm for 30 minutes to clean the chips, and residual moisture on the surface and inside was removed in a vacuum dryer (FIG. 4). The cleaned chips are shown in Fig.

The cleaned chips were mixed with silicon carbide (FIG. 1 (b)) separated from waste silicon sludge by-products purchased from Yukin Chemical and put into a planetary miller (FIG. 7). At this time, the silicon carbide was mixed with 10 wt% of the chip.

 The planetary miller was purchased with a water-cooled planetary mill (Fig. 6) of Woongbi Machine, and the interior of the jar was exchanged with argon gas. The barrel was made of zirconium, two of which had a capacity of 120 ml, and the ball inside the barrel was made of zirconium and having a diameter of 10 mm. The planetary mirror was operated at 500 rpm for 30 minutes to obtain an aluminum-silicon carbide powder.

Example 2

The same procedure was performed as in Example 1, except that the silicon carbide content was 5 wt% based on the cutting chips.

Comparative Example 1

The same procedure was performed as in Example 1 except that the silicon carbide content was 3 wt% based on the cutting chips.

Comparative Example 2

The same procedure was performed as in Example 1, except that the silicon carbide content was 1 wt% based on the cutting chips.

Comparative Example 3

The same operation was performed except that the operation time of the planetary mirror was changed to 5 minutes in the first embodiment.

Comparative Example 4

The same operation was performed except that the operation time of the planetary mirror was changed to 5 minutes in the second embodiment.

Comparative Example 5

In the same manner as in Example 1 except that the aluminum chip cleaning step was not performed.

Experimental Example 1

The aluminum-silicon carbide powders prepared in Examples 1 to 2 and Comparative Examples 1 to 4 were examined for the shape of the powders to determine whether or not they were pulverized. The respective experimental conditions and results are shown in Table 1 below.

No. speed
(rpm) SiC (wt%) time
(min) all
weight
(g) SiC
weight
(g) Al
weight
(g) Ball
(g) Remarks Example 1 500 10 30 16.404 3.66 12.744 136.78 Grinding is done well. Example 2 500 5 30 15.282 1.83 13.452 136.78 Grinding is done well. Comparative Example 1 500 3 30 14.833 1.098 13.735 136.78 Not crushed Comparative Example 2 500 One 30 14.384 0.366 14.018 136.78 Not crushed Comparative Example 3 500 10 5 16.404 3.66 12.744 136.78 Not crushed Comparative Example 4 500 5 5 15.282 1.83 13.452 136.78 Not crushed Comparative Example 5 500 10 30 16.404 3.66 12.744 136.78 Not crushed

As shown in Table 1, in the case of the examples, the powder was well pulverized and could be made into a powder (Fig. 8 (b), Fig. 9), but it was too low in the content of silicon carbide, , And when the pulverization time was short, pulverization was incomplete and the powder phase could not be obtained (Fig. 8 (a)).

Example 3

To confirm additional process conditions, a water-cooled Planetary Mill of Woobie Machine was purchased to produce an aluminum-silicon carbide composite powder. The cutting chips were cleaned in the same manner as in Example 1, and the inside of the jar was used by gas exchange with argon. The barrel was made of stainless steel (SUS) with a capacity of 500 ml, and the ball inside the barrel was made of stainless steel with a diameter of 10 mm. The results of each experiment are shown in Table 2 below.

No. speed
(rpm) SiC% time
(min) all
Weight (g) SiC weight
(g) Al Weight
(g) Ball
(g) Mt. (g) Remarks One 500 0 30 70.8 0.00 70.80 1654 - Almost not crushed 2 500 One 30 71.922 1.83 70.09 1654 - 3 500 3 30 74.166 5.49 68.68 1654 - 4 500 5 30 76.41 9.15 67.26 1654 - 5 500 10 30 82.02 18.30 63.72 1654 - 6 300 3 10 100 7.40 92.60 1654 1.5 Almost no crushing 7 300 5 10 100 11.97 88.03 1654 1.5 Almost no crushing 8 300 3 20 100 7.40 92.60 1654 1.5 Fines are fine or almost free of shattering 9 300 5 20 100 11.97 88.03 1654 1.5 10 300 3 30 100 7.40 92.60 1654 1.5 11 300 5 30 100 11.97 88.03 1654 1.5 12 300 3 60 100 7.40 92.60 1654 1.5 Powder is hot and smoke is m. Particles are very fine or almost free of shattering 13 300 5 60 100 11.97 88.03 1654 1.5 Despite cooling down during the weekend, the powder is hot,
Mixture of particles with little or no fracture 14 500 3 10 100 7.40 92.60 1000 1.5 Almost no crushing 15 500 5 10 100 11.97 88.03 1000 1.5 Almost no crushing 16 500 3 10 + 10 35.4 2.62 32.78 1645 0.531 Well-crushed 17 500 5 10 + 10 35.4 4.24 31.16 1645 0.531 Crushing is done well 18 500 3 10 + 10 100 7.40 92.60 1645 1.5 Not crushed 19 500 5 10 + 10 100 11.97 88.03 1645 1.5 20 500 3 20 40 2.96 37.04 1600 0.6 5, 10 minutes Confirmation result was not good, 20 minutes experiment, finely crushed 21 500 5 10 40 4.788 35.212 1600 0.6 5 minutes Confirmation was less than 10 minutes at the time of confirmation, finely crushed 22 500 5 22 40 4.788 35.212 1600 One At the 7 minute check, the pulverization was less and the experiment was 22 minutes, 2 pieces were crushed, 2 pieces were not crushed. 23 500 5 20 40 4.788 35.212 1600 0.8 Not crushed 24 500 5 20 40 4.788 35.212 1600 0.8 15 minutes check, less broken and 5 minutes more milling 25 500 5 60 100 11.97 88.03 2000 1.5 Powder recovery: 260g (140g loss), large ball 1600g + small ball 400g charge 26 300 5 15 100 11.97 88.03 2000 1.5 Recovery of powder attached to ball and jar, shiny color with damp feeling, 130g recovery 27 500 5 30 100 11.97 88.03 2000 1.5 Acquisition 390g 28 500 5 30 100 11.97 88.03 2000 1.5 Only 2000g for large balls 29 500 5 30 100 11.97 88.03 2000 1.5 Well broken, I feel rather small powder 30 500 5 30 100 11.97 88.03 2000 1.5 31 500 5 30 100 11.97 88.03 2000 1.5 32 500 5 30 100 11.97 88.03 2000 1.5 33 500 5 30 100 11.97 88.03 2000 1.5 34 500 5 20 100 11.97 88.03 2000 1.5 Well crushed but slightly larger than 30 minutes 35 500 5 20 100 11.97 88.03 2000 1.5 36 500 5 30 100 11.97 88.03 2000 1.5 AlSiC of color and particle similar to existing Si + SiC is produced *

As a result of repeated experiments under various conditions as shown in the above Table 2, the optimal conditions were a reaction rate of 500 rpm, a reaction time of 30 min, a total feed of 100 g, a ball volume of 2 kg, a SiC content of 5% Acid: 1.5 g was obtained.

Experimental Example 2

The grain size of the aluminum-silicon carbide composite powder produced under the optimum conditions of Example 3 was analyzed. As shown in FIG. 10, the aluminum-silicon carbide composite powder of the present invention has a size of 10-400 탆.

Experimental Example 3

For the analysis of the aluminum-silicon carbide composite powder prepared under the optimum conditions of Example 3, a specimen was prepared as shown in FIG.

As shown in FIG. 12, it was found that the higher the content of silicon carbide was, the better the dispersion was, and the size of the powder was reduced as the milling time became longer, but it was the same size after a certain period of time. Also, in the case of ductile aluminum powder, a thinner thickness was observed due to collision with the milling balls.

Experimental Example 4

The EDX analysis of the aluminum-silicon carbide composite powder prepared under the optimum conditions of Example 3 was performed. As shown in FIG. 13, no aggregation of the silicon carbide on the low-magnification image was observed, which is considered to be due to the fact that SiC is dispersed to cover the surface of the aluminum powder uniformly and SiC introduced into the powder is large.

Experimental Example 5

An X-ray mapping analysis of the aluminum-silicon carbide composite powder prepared under the optimum conditions of Example 3 was performed. As shown in FIG. 14, Si and C were uniformly distributed throughout the powder, and the powders were found to be pulverized and dispersed to a fine size.

Experimental Example 6

The cross-section of the aluminum-silicon carbide composite powder produced under the optimum conditions of Example 3 was analyzed. As shown in Fig. 15, a portion indicated by a red circle was SiC particles dispersed in aluminum particles, and it was found that the particles were uniformly dispersed in the matrix.

Example 4

The aluminum-silicon carbide composite powder produced under the optimum conditions of Example 3 was compression-sintered to produce a billet in the following manner.

 A) The temperature in the chamber is increased from room temperature to 430 ° C at a rate of 7 ° C / min and then maintained for 150 minutes.

→ The actual temperature is raised to 400 ° C at relatively high speed and then slowly raised to 430 ° C (the time actually maintained at 430 ° C is about 80 minutes).

B) De-gassing: Removal of harmful gas inside the manufactured primary molded body under vacuum (~ 10 ^-2 torr).

C) After de-gassing, the temperature was raised to 700 ° C at a rate of 11 ° C / min, and then maintained for 90 minutes

→ In actual practice, both temperature rise (about 570 ℃) and temperature rise (60min) and hold time (90min)

D) Sintering: In order to remove the pores in the primary molded body, to reduce the pore between powder and powder, and to compact the powdered structure, pressurized for 30 minutes at 15 MPa

The final sintered compact of Al-SiC composite powder was manufactured into a cylindrical shape having a diameter of 70 mm and a height of 37 mm (FIG. 18).

Comparative Example 6

A billet was prepared in the same manner as in Example 4, except that it was pressurized at room temperature without a heating step. As a result, as shown in Fig. 17, it was found that the produced billets could not be formed due to lack of densification.

Example 5

For the extrusion and characterization of the aluminum-silicon carbide composite powder, extrusion experiments were carried out using the billets prepared in Example 4. The extrusion conditions are as follows.

A) Extrusion equipment: 3 inches / 600 tons

B) Extrusion mold: 3.0 × 27.0 × 2 Hole

C) Mold and extrusion temperature: 480 ℃

D) Required billets: 7 pieces (total 259mm)

Two extruded materials were produced under the above conditions, and the extruded material was made to have a thickness of 3.0 mm, a width of 27.0 mm and a length of 2400 mm (FIG. 20).

Experimental Example 7

In order to examine the physical properties of the extruded product prepared in Example 5, an official test result was requested. The rolling site was Honam region headquarters of the Korea Institute of Industrial Technology (KITI) and the rolling conditions were 500 ° C and 8pass (Fig. 21). 22 to 24 and Table 3 show the results.

division Measure The tensile strength 428.25 MPa Elongation 5% Thermal conductivity 130.44 W / mK density 2.75

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 thereto will be. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (9)

(a) cutting, washing and drying aluminum cutting chips as a first raw material;
(b) mixing silicon carbide (SiC) as the first raw material with a second raw material and then pulverizing the mixture to produce an aluminum-silicon carbide composite powder; And
(c) compressing and sintering the aluminum-silicon carbide composite powder to produce a compression-molded body;
/ RTI >
Wherein the step (b) is performed at 100 to 1000 rpm for 5 to 60 minutes using a planetary miller, and the weight ratio of the second raw material to the first raw material is 5 to 10 parts by weight. delete delete The method according to claim 1,
Wherein the silicon carbide is derived from a silicon ingot cutting process by-product of a solar panel or a semiconductor. 5. The method of claim 4,
Wherein the silicon carbide is produced by subjecting the by-product of the silicon ingot cutting process to an acid treatment followed by ultrasonic spraying. The method according to claim 1,
Wherein the step (a) is a step of mixing the first raw material with the water and the cleaning agent, followed by washing using a centrifugal separator, and drying using a vacuum drier. delete The method according to claim 1,
The step (c) comprises:
(i) inserting an aluminum-silicon carbide composite powder into a chamber;
(ii) first heating the chamber to a temperature of 350 to 500 ° C at a rate of 2 to 10 ° C / min;
(iii) decompressing the chamber to remove gas inside the formed body;
(iv) secondarily heating the chamber to 520 to 900 ° C at a rate of 5 to 15 ° C / min; And
(v) compressing the chamber at a pressure of 5 to 100 MPa for 10 to 60 minutes;
≪ / RTI > aluminum-silicon carbide. 8. Aluminum-silicon carbide produced by the process of any one of claims 1, 4 to 6 and 8.

Images