KR100784992B1 - Alloy target and method for manufacturing alloy target by mechanical alloying and sintering - Google Patents

Abstract

A manufacturing method of a target for coating is provided to manufacture a multicomponent target for high speed processing tools having fine and uniform grains and excellent physical properties, and a target for coating manufactured by the manufacturing method is provided. A manufacturing method of a target for coating comprises: a step(S1) of mixing a raw material powder with balls and performing a mechanical alloying process to constantly distribute one element of Ti, Cr and W and at least one element of Al, Si, C, N and O in the raw material powder and form grains in the raw material powder into nano-sized fine particles at the same time; a step(S2) of performing a sintering process of the raw material powder with the fine particles to form a sintered body in which all elements contained in the raw material powder are constantly distributed, and the grains in the powder is formed into nano-sized fine particles at the same time; and a step(S3) of processing a top surface of the sintered body using ultrasonic waves, and adhering a back plate to a bottom surface of the sintered body to manufacture a sputtering or arc target for improving the life of high speed processing tools, wherein the balls have a size range from 1/16 to 8/16 inch.

Description

Coating target manufacturing method and product thereof {Alloy target and method for manufacturing alloy target by Mechanical Alloying and Sintering}

1 is a block diagram sequentially listing the method for manufacturing a target for coating according to the present invention,

2 is a cross-sectional view showing the structure of a ball mill for a mechanical alloying process in the fine granulation step according to the present invention,

3 is a graph of a multi-component alloy system made by the mechanical alloying process according to the present invention,

Figure 4 is a photograph showing the distribution of alloying elements in the powder subjected to the mechanical alloying process according to the present invention,

Figure 5 is a photograph showing the microstructure of the powder subjected to the mechanical alloying process according to the present invention,

6 is a schematic view showing an apparatus for a spark plasma sintering process in the sintered body forming step according to the present invention;

7 is a graph showing the shrinkage of the sintered body during the spark plasma sintering process according to the present invention;

8 is a flowchart sequentially illustrating a process of a target manufacturing step according to the present invention.

* Description of the major symbols in the drawings *

10: target 20: sintered body

30: back plate 35: brazing sheet

T: processing tool S1: fine granulation step

S2: sintered body forming step S3: target manufacturing step

The present invention relates to a target manufacturing process and a product thereof, and more particularly, to a coating target manufacturing method and a product for manufacturing a target for a multi-component high-speed processing tool having fine, uniform and excellent physical properties. It is about.

In general, for various purposes such as improving the wear resistance of cutting tools such as chips, drills, end mills, and the like, the coating of the cutting tools is performed using various coating methods.

There are various processes such as sputtering, arc ion plating, physical vapor deposition, etc. Among these, sputtering is a process in which atoms or molecules are splashed from a target when particles with energy collide with the target. It means forming a thin film on the surface of the substrate.

The principle is that if the target is applied to the (-) pole and the substrate is the (+) pole, and a high voltage is applied in an Ar atmosphere of 1 to 2 Torr, the Ar gas near the (-) pole is ionized and becomes Ar ⁺ , To crash. Molecules or atoms protruding by the ion bombardment are attached to the substrate of the (+) electrode to form a thin film.

Arc ion plating is a method of forming a thin film by a similar principle, and activates the target material in the arc region, not the plasma region. As such, the surface of the substrate material on which the thin film is formed by sputtering or arc ion plating from the target material has a decorative color such as gold or silver, and has characteristics such as corrosion resistance and wear resistance through high hardness and excellent physical properties.

On the other hand, in recent years in various manufacturing industries, including automobiles, shipbuilding, electronics, high speed and high efficiency of the cutting process is urgently required. The core of this demand is high-speed processing technology, which enhances the company's competitiveness as productivity increases.

In order to cope with this, a cutting tool for high-speed machining is a trend to introduce a high-performance coating film having excellent durability and corrosion resistance.

In particular, as an example by high-speed processing, high heat (700 ~ 800 ℃) occurs, it is characterized by a high feed rate. The characteristics of the high-performance coating film must be able to withstand the high temperatures generated during high-speed processing (excellent oxidation resistance), avoid the precise chip tip phenomenon common in high-speed processing (good toughness), and improve the wear resistance (excellent hardness). Coating film development is essential.

As an optimal coating layer for improving the service life of such a high speed machining tool, recently, it is required to form a multi-component and nano-ized coating layer in which elemental components such as Ti, Cr, Al, and Si, which can improve physical properties, are complexed.

However, in order to form a multi-component coating layer on the tool as described above, there is a problem that an individual target corresponding to the number of elements included in the coating layer is required, and in order to uniformly distribute various components, the position of the target and the related process Because of the complexity of determining the parameters of, the optimization of the process involved is practically impossible and has been difficult to apply.

On the other hand, as another method for solving the above problems there is also a method for manufacturing a coating layer by including a variety of alloying elements included in one target. To this end, the target of the composite system, that is, to make an alloy system in which Ti, Al, Cr, Si, W, etc. are mixed, but there is a problem in that it is difficult to manufacture due to the difficulty of alloying, processing and the like.

The present invention has been made in order to solve the conventional problems as described above, the coating target manufacturing method for producing a target of the multi-component system having a fine, uniform and excellent physical properties through mechanical alloying process and sintering process And providing the product.

The coating target manufacturing method of the present invention for achieving the above object, in the target manufacturing method used for sputtering or arc target for improving the life of the high-speed processing tool, a predetermined ratio of the raw material powder and the ball of a predetermined size After mixing at a charge ratio of and performing a mechanical alloying process to uniformly distribute any one element of Ti, Cr, W and at least one element of Al, Si, C, N, O inside the raw material powder At the same time fine granulating the grains inside the powder to nano size; After inputting the raw material powder after the fine granulation step, the sintering process is performed to uniformly distribute all elements contained in the raw material powder and to form a sintered body in which the grains in the powder are finely granulated to nano size. Making a step; After processing the upper surface of the sintered body by using ultrasonic waves, and comprising a step of manufacturing a target by adhering a back plate on the lower surface of the sintered body.

In addition, in the target used for the sputtering or arc target for improving the life of the high-speed processing tool, a raw material powder and a ball of a predetermined size are mixed at a predetermined ratio of charge ratio, and then a mechanical alloying process is performed to perform Ti, At least one element of Cr, W and at least one element of Al, Si, C, N, O are uniformly distributed, and the grains inside the powder are finely granulated to a nano size and the fine particles After inputting the raw powder, the sintering process is performed to uniformly distribute all the elements contained in the raw powder, and to form a sintered body in which the crystal grains in the powder are finely granulated to a nano size, using ultrasonic waves. After processing the upper surface of the sintered body, the back plate is bonded to the lower surface of the sintered body, characterized in that the manufacturing.

When described in detail with reference to the accompanying drawings a preferred embodiment of the present invention.

1 to 8 are directed to the coating target manufacturing method and the product of the present invention, first, the coating target manufacturing method as shown in Figure 1 fine granulation step (S1), sintered body forming step (S2), and the target It is composed of a manufacturing step (S3).

In detail, in the fine granulation step (S1), the raw material powder and the ball having a predetermined size are mixed at a charging ratio of a predetermined ratio, and then a mechanical alloying process is performed to form any one of Ti, Cr, W, Al, At least one or more elements of Si, C, N, and O are uniformly distributed and at the same time, the grains inside the powder are finely granulated to nano size.

Here, the mechanical alloying process (Mechanical Alloying (MA)) described above is briefly described, in which a powdered specimen is put together with a ball into a container of a certain size and alloyed by a mechanical force. All the reactions are performed, which makes it possible to alloy even between alloying compositions that are difficult to alloy, and is an optimal process for dispersing oxides and carbides with little solid solution.

In addition, it is possible to refine the grains by sufficient energy therein to produce not only micrometer-sized grains, but also powders having grain sizes of less than nanometers.

Referring to the fine granulation step (S1) through the mechanical alloying process as described above in more detail through Figure 2, after mixing the raw powder and the ball in a ball mill in a ratio of 1: 5 to 1: 500 by weight, By maintaining the ball mill in a gas atmosphere or a vacuum atmosphere to drive a rotation for 10 to 100 hours at a speed of 50 ~ 1000rpm, mechanical alloying is achieved.

At this time, the gas atmosphere may be selectively employed depending on the working conditions such as air, nitrogen, carbon, hydrogen, argon, oxygen, mixed gas.

And, the size of the ball is to use a 1 / 16inch ~ 8 / 16inch, the reason is that when the size of the ball is less than 1 / 16inch, it is not possible to supply enough energy to the inside of the ball mill has a grain refinement effect inside the raw material powder If the size of the ball exceeds 8/16 inch, the amount of the ball is reduced by weight, and the size of the ball has a large effect, which adversely affects the particle size reduction. That is, the size limitation of the balls is essential for proper mechanical alloying.

FIG. 3 is a graph schematically showing an example of a multicomponent alloy system that may be manufactured by the mechanical alloying process. The multicomponent alloy system may be formed by establishing process parameters through the mechanical alloying process. As a result, the target 10 including various elements can be manufactured.

In addition to the graph of FIG. 3 described above, alloy systems such as a Ti-Al-N component system, a Ti-Si-N component system, a Ti-Al-Si-N component system, and a Cr-Al-Si-N component system are manufactured from Ti-N. In particular, wear resistance can be greatly improved by adding Si element. In addition, alloys such as carbides (Ti-Al-C, Ti-Al-Si-C, etc.) and carbonitrides (Ti-Al-CN, Ti-Al-Si-SN), which are not nitrides, are controlled by controlling the atmosphere of the ball mill. Manufacturing is possible.

Subsequently, in the sintered body forming step (S2), after inputting the raw material powder which has undergone the fine granulation step (S1), the sintering process is performed to uniformly distribute all the elements contained in the raw material powder, and at the same time, to crystallize the grains inside the powder. The sintered compact 20 in the state of fine granulation to a nano size is formed.

In this case, as the sintering process, hot isostatic pressing or spark plasma sintering may be used.

Among these, the spark plasma sintering process (Spark Plasma Sintering, SPS) is briefly described. The surface is activated by applying an electric current to the powder under a constant pressure to generate plasma between the powder particles, thereby activating the surface at a low temperature. Is a method of rapidly sintering a powder.

The spark plasma sintering process is easy to sinter high-temperature materials or oxides that are difficult to sinter by strong powder surface activation due to plasma generation, and also enables rapid sintering at low temperatures. The structure is maintained and sintered.

Referring to the sintered body forming step (S2) through the spark plasma sintering process as described above in more detail with reference to Figure 6, after the raw material powder granulated according to the size of the sintered body 20 to be prepared between the jig, The sintered body 20 is manufactured by applying a sintering pressure and applying a high current density DC pulse current to generate plasma between the raw material powders and activating the surface.

Next, in the target manufacturing step (S3), after processing the upper surface of the sintered body 20 using ultrasonic waves, the back plate 30 is adhered to the lower surface of the sintered body 20 to manufacture the target 10.

Referring to FIG. 8 in detail, ultrasonic vibration is generated up to 20000 times in the processing tool T to form a part of the upper surface of the sintered body 20 first, and then the processing tool T is moved up, down, left. , Right, transfer in a circular motion to form the upper surface of the sintered body 20 to the desired shape. In the present invention, the center of the upper surface is formed in a recessed shape, but the upper surface of the sintered body 20 is not limited to the recessed shape as described above.

Then, the brazing sheet 35 is inserted between the lower surface of the sintered body 20 and the back plate 30 and then heated to bond the sintered body 20 and the back plate 30 to complete the manufacture of the target 10. do.

On the other hand, the target 10 manufactured by the coating target manufacturing method described above, by performing the mechanical alloying process and the spark plasma sintering process sequentially, any one element of Ti, Cr, W and Al in the raw material powder , At least one of Si, C, N, and O is uniformly distributed, and the sintered body 20 is manufactured in a state in which the grains inside the powder are finely granulated to a nano size.

At this time, the grain size inside the raw powder after the mechanical alloying process is formed to less than 1㎛ to induce fine arc control and uniform distribution of the composite component, the size of the raw powder is 1 ~ to improve the sintering characteristics It forms by adjusting between 20 micrometers.

In addition, the grain size inside the raw material powder after the sintering process and the size of the raw material powder are also formed between 1 μm and 1 to 20 μm, respectively, as in the case after the mechanical alloying process.

As described above, the alloy system formed after the mechanical alloying process may be represented by (Ti _a , Cr _b , W _c )-(Al _d , Si _e )-(C, N, O). In this case, 0.7 ≦ a + b + c ≦ 1, 0 ≦ d + e ≦ 0.3, and a, b, c, d, and e represent atomic ratios of Ti, Cr, W, Al, and Si, respectively.

Subsequently, the sintered body 20 formed through the above process is processed and formed into a desired shape by using ultrasonic waves on the upper surface thereof, and the back plate 30 is adhered to the lower surface of the sintered body 20 to manufacture the target 10. .

Here, the sintered compact 20 and the back plate 30 are adhered by inserting and heating the brazing sheet 35 between the sintered compact 20 and the back plate 30. At this time, the back plate 30 is a different material from the sintered body 20, it is suitable to be made of a material such as aluminum or copper excellent in the heat transfer coefficient, but in addition to the above-mentioned aluminum or copper, another material having good heat transfer power It may be used that is obvious in the practice of the present invention.

Referring to the operation and effect of the present invention configured as described in detail as follows.

In order to manufacture the target 10 through the coating target manufacturing method of the present invention, first, the raw material powder and balls are mixed in a ratio of 1: 5 to 1: 500 in a ball mill as shown in FIG. Drive at speed for 20 hours or more.

Figure 4 is an experimental example when the Ti, Al, Si alloy element is included in the raw material powder, SEM image showing the distribution of alloy elements after the mechanical alloying process through the rotational drive as described above. Looking at this, the Ti, Al, Si alloy elements that were not uniform until the milling process for 5 hours can be confirmed that evenly distributed in the powder after 20 hours.

In addition, the grain structure inside the powder prepared after 20 hours has a size of less than 1㎛ (5 ~ 20nm) as shown in Figure 5 can induce fine arc control and uniform distribution of the composite component, The size of the raw material powder is formed to have a constant spherical shape between 10 μm to improve the sintering characteristics.

Therefore, through the above-described mechanical alloying process, various alloying elements can be uniformly distributed in the raw material powder, and the grain size inside the powder can be finely granulated to a size of less than 1 μm, and the size of the powder itself is also uniformly secured. You can do it.

In this manner, after the powder having a fine structure is produced, the step of molding the powder is generally performed at a temperature that is two thirds of the melting point of the alloy.

However, when forming through the above method, the forming temperature of the multi-component alloy system is raised to 1000 ℃ or more, when the sintering is performed under such a high temperature and a constant pressure, the metastable microstructure is grain growth Disappeared by In addition, when sintering a large molded body in the horizontal direction under one-way pressure, such as hot pressing (Hot Pressing), it is difficult to obtain a uniform density in the specimen due to the uneven distribution of pressure.

Therefore, hot isostatic pressing (Hot Isostatic Pressing), which makes the pressure isotropic, is used a lot, and further, the powder is sintered by using the spark plasma sintering process, which is a representative sintering method that can minimize the sintering time or lower the sintering temperature. will be.

In order to sinter the powder as described above, as shown in FIG. 6, an optimum powder amount necessary for the sintered compact 20 having a desired size is put between the jig, and a DC pulse current of high current density is applied. Therefore, plasma is generated between the powders to activate the surface, so that the powder can be sintered in a short time.

At this time, the sintered body 20 to be sintered as described above is observed the degree of shrinkage of the sintered body 20 during the sintering while generating a plasma to raise the temperature and determine the point where no further shrinkage is observed as the optimum sintering point .

The reason is that after the sintering shrinkage no longer occurs, the continuous generation of plasma causes the alloy powder due to excessive heat to be liquefied, resulting in higher unevenness of the structure. Therefore, when the shrinkage of the sintered compact 20 is no longer observed, the sintered compact 20 having an optimal sintered density of 99% or more can be obtained as shown in the graph of FIG. 7.

As such, after the sintered body 20 is produced, the sintered body 20 is processed, and the back plate 30 is bonded to manufacture the target 10.

Referring to FIG. 8 in detail, first, ultrasonic vibration is generated up to 20000 times in the processing tool T to process a part of the upper surface of the sintered body 20. Thereafter, the processing tool T is transferred along the area of the upper surface of the sintered body 20 to be processed in up, down, left, right, and circular motions, and the upper surface portion of the sintered body 20 is processed by processing the entire upper surface of the sintered body 20. It can be manufactured in a desired shape.

At this time, the processing of the sintered body 20 is made by ultrasonic waves, it is possible to easily process within a short time without the generation of frictional heat.

As such, after processing, the back plate 30 made of copper or aluminum is bonded to the lower part of the sintered body 20, wherein the brazing sheet 35 is formed between the sintered body 20 and the back plate 30. After inserting and heating, the sintered compact 20 and the backplate 30 are bonded together, and finally manufacture of the target 10 can be completed.

Here, the reason for using the back plate 30 in the target manufacturing process as described above is because the target itself is very hard and expensive because it is very inefficient to manufacture and process the target using only the sintered body 20 without any other material. That is, by manufacturing the back plate 30 made of a material such as aluminum or copper and used in the manufacture of the target, it is not only excellent in thermal efficiency, but also secures a thermally stable target, and also secures high competitiveness in processing and price. You can do it.

On the other hand, the present invention has been described in detail only with respect to the specific examples described above it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, it is natural that such variations and modifications belong to the appended claims. .

As described above, the present invention can finely granulate the grains in the raw material powder to nano size through the mechanical alloying process and the sintering process, and ensure the powder in a uniform size, and in particular, uniform the various alloy elements inside the raw material powder. Can be distributed. Therefore, there is an effect that can be used as a next-generation coating material of the high-speed processing tool by producing an alloy sintered body having excellent physical properties.

Furthermore, rather than installing and coating several targets separately for multi-component coatings, a series of materials required for manufacturing are formed by uniformly distributing various alloying elements in an alloy that has undergone a mechanical alloying process to form a nanocomposite structure with one target. It also has the effect of simplifying and simplifying the process.

In addition, by manufacturing a target by bonding a back plate made of a material having excellent thermal conductivity to a sintered body, it is not only excellent in thermal efficiency, but also secures a thermally stable target, and also has a high competitiveness in processing and price. There is also.

Claims (13)

delete delete delete After mixing the raw material powder and the ball at a predetermined ratio, a mechanical alloying process is performed to form at least one of Ti, Cr, and W and at least one of Al, Si, C, N, and O in the raw material powder. At the same time, the particles are uniformly distributed and finely grained to a nano size, and the raw material powder subjected to the fine granulation step is added, followed by a sintering process to remove all elements contained in the raw material powder. Forming a sintered body in a state of uniformly distributing the crystal grains in the powder to a nano size, and processing the upper surface of the sintered body using ultrasonic waves, and then attaching a back plate to the lower surface of the sintered body to produce a target. In the method for manufacturing a target used for the sputtering or arc target for improving the life of the high-speed machining tool, including the step of: The size of the ball is 1 / 16inch ~ 8 / 16inch coating target manufacturing method, characterized in that using that. delete The method of claim 4, wherein the sintering process in the sintered body forming step using a spark plasma sintering (Spark Plasma Sintering), the spark plasma sintering process is a raw material powder granulated according to the size of the sintered body 20 to be manufactured The method of manufacturing a target for coating, characterized in that after the injection between the jig, while applying a sintering pressure and a high current density DC pulse current to generate a plasma between the raw material powder and activate the surface to sinter. delete The method of claim 4, wherein the target manufacturing step generates ultrasonic vibration in the processing tool (T) to preferentially form and form a part of the upper surface of the sintered body (20), and then, the processing tool (T) in up, down, left, right. , By transferring in circular motion to process the upper surface of the sintered body 20 to a desired shape, and inserting the brazing sheet 35 between the lower surface and the back plate 30 of the sintered body 20 and heated to heat the sintered body 20 and the back plate Method for producing a target for coating, characterized in that for bonding (30). delete delete delete delete After mixing the raw material powder and the ball at a predetermined ratio, a mechanical alloying process is performed to form at least one of Ti, Cr, and W and at least one of Al, Si, C, N, and O in the raw material powder. And uniformly distributing the crystal grains in the powder to nano size, and injecting the finely granulated raw powder, and performing a sintering process to uniformly distribute all the elements contained in the raw powder. At the same time, to form a sintered body in the state of finely granulated the crystal grains in the powder to a nano-size, by processing the upper surface of the sintered body using ultrasonic waves, and by attaching a back plate to the lower surface of the sintered body to improve the life of the high-speed processing tool In the target used for sputtering or arc targets, The alloy system after the mechanical alloying process, (Ti _a , Cr _b , W _c )-(Al _d , Si _e )-(C, N, O) A coating target, wherein 0.7 ≦ a + b + c ≦ 1 and 0 ≦ d + e ≦ 0.3. Here, a, b, c, d and e represent the atomic ratios of Ti, Cr, W, Al and Si, respectively.

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