KR101849650B1 - Method of manufacturing a bi-layered friction machine parts made of selective internal oxidation copper alloy - Google Patents

Abstract

The present invention provides a method to manufacture bi-layered friction machine parts using a selective oxidation process, providing excellent strength and wear resistance at high temperature. According to the present invention, the method comprises: a process of preparing copper alloy-based powder including one or more kinds among greater than 15 to 20 or less weight percent of Zn, 5 to 10 weight percent of Sn, 0.01 to 2 weight percent of Al, 0.01 to 2 weight percent of Si, 0.01 to 2 weight percent of Ti, 0.01 or less weight percent of P, and the balance of Cu and covering the powder on a surface of a metal base material to form a coating layer; a process of maintaining the metal base material having the coating layer formed thereon at 700 to 800 °C for 10 to 40 minutes to perform selective oxidation, to uniformly form and disperse a fine second phase oxide with a nano-size of the one or more kinds selected among Al_2O_3, SiO_2, and TiO_2 inside the coating layer; a process of sintering the coating layer having the second phase oxide dispersed therein at 760 to 880 °C for 10 to 40 minutes under a reduction atmosphere to prevent oxidation of Cu and a change of an alloy composition to integrate the coating layer to the metal base material; and a process of forming the metal base material integrated with the coating layer to produce a machine part with a predetermined shape.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a manufacturing method of a double-layered friction machine member using a selective oxidation process,

More particularly, the present invention relates to a method of manufacturing a mechanical member having a double structure in which a copper alloy powder is coated on a surface of a base metal, (Oxide) uniformly distributed in the matrix within a range of 0.05 to 20 nm by using a selective oxidation process to produce a friction member having a double structure having excellent friction characteristics and abrasion resistance.

Generally, a high strength copper alloy widely used as a mechanical member or a structural material in a non-ferrous alloy is formed by adding an alloy element such as aluminum (Al), nickel (Ni), silicon (Si), manganese (Mn) It is an alloy produced by melt-casting and shows a single structure and excellent mechanical properties such as abrasion resistance, tensile strength and toughness. Especially, it is widely used to make worm wheel, bearing, slipper for compressor, and other high-speed motion parts for automobile synchronizer ring and general machine, and the usage amount as related parts is also steadily increasing. One example of such a technique is the invention described in Patent Document 1. [ The patented invention includes a composition comprising 55 to 75 wt% copper, 0.1 to 8 wt% aluminum, 0.3 to 3.5 wt% iron, 0.5 to 8 wt% manganese, 0 to less than 5 wt% nickel, 0 to 0.1 wt% Less than 0% lead, 0-3 wt% tin, 0.3-5 wt% silicon, 0-0.1 wt% cobalt, 0-0.05 wt% titanium, 0-0.02 wt% And a copper-zinc alloy containing a remaining amount of zinc, using a pure metal, to produce a high-strength copper alloy.

However, the parts made of high strength copper alloy composed of a single structure are somewhat lacking in abrasion resistance, so that when the machine is used for a long period of time, due to wear and shock due to rotational motion, In addition, there is a problem that the life of these parts is shortened or sometimes these parts are broken. Recently, since the power transmission mechanism of an automobile transmission has a tendency to require momentarily strong force and large torque transmission, a material having a high frictional coefficient and excellent abrasion resistance is required as a synchronizer ring component material. However, It is difficult to meet the characteristics of high-strength copper alloy materials. In addition, as the demand for lightweight parts and high-performance parts increases, a feeling of softness in handling is required along with the upgrading of the mission and the high performance in the field of transmission, and parts with excellent friction characteristics and wear resistance are required.

Components used in the automotive transmission industry generally have high mechanical strength, excellent friction characteristics on the inner circumferential surface in contact with the mating member, and sufficient abrasion resistance, so that various manufacturing methods are known. As a method of manufacturing parts used in the conventional automotive transmission, there are a method of uniformly mixing ceramics oxide (Mo-based oxide) having high melting point and hardness as a metal and a dissimilar metal and using the plasma, A method of attaching an inner circumferential surface by a flame spraying method from a sintered body obtained by mixing and molding a nonmetal powder and sintering at a high temperature has been used. However, in the case of parts used in the automotive transmission manufactured by such a manufacturing method, There is a problem that quality inequality occurs due to insufficient strength due to shortage or unevenness of the material of the film, resulting in poor friction characteristics and abrasion resistance. Particularly, in the case of manufacturing components used in the automotive transmission by plasma spray coating, the surface heat peeling phenomenon due to the difference in thermal expansion coefficient between the base material and the surface layer occurs due to the frictional heat generated during the gear shift, There is a problem that friction characteristics are lowered by causing surface defects, and wear of the mission-related parts is caused by dropping of attached particles. As an example of this technique may be made of the invention described in Patent Document 2, Patent Document 2 to 80% brass powder, silicon oxide (SiO ₂₎ 4-6%, aluminum oxide _{(Al 2 O 3) 0.5-1.5%} , carbon (C) 4-6%, tin (Sn) 3.5-6.5%, iron (Fe) 18-22% or less, and the metal powder and the oxide powder are mixed and sintered have.

In order to solve these problems, recently, a component made of a copper alloy having excellent thermal conductivity has been used. Considering the bonding force between the metal and the dissimilar metal, the bainite and the pearlite and the glass Fe- Components produced from sintered alloys are generally used.

On the other hand, copper alloy sintered alloys with high strength and thermal conductivity are used in various mechanical parts (turbocharged bearings, engine valve guides, thrust receiving parts and key parts of gear pumps) in addition to synchronizer rings. However, in the case of the copper alloy-based sintered alloy, the difficulty in sintering due to the high oxidation of copper occurs, and in some cases, the alloy component evaporates. That is, the oxidation phenomenon of copper and the alloying element having a low boiling point are evaporated in the sintering process, and the ratio thereof is decreased. As a result, it is difficult to maintain the composition of the copper alloy sintered body and sufficient bonding force between the base metal and the dissimilar metal is not secured. There is a problem that defects are caused on the surface of the product or the mechanical characteristics and composition of the surface and the center portion of the sintered body are uneven and the quality is deteriorated. As an example of such a technique, the invention disclosed in Patent Document 3 can be cited. In Patent Document 3, the ratio of zinc (Zn) is 10-15% and the ratio of tin (Sn) is 4-7% And the ratio is 0.3% or less.

In recent years, parts for adhering carbon fibers to a steel surface by using an adhesive have been developed to provide excellent wear resistance and friction coefficient, but also problems of carbon fiber desorption due to friction resistance heat are also caused.

As described above, for the mechanical parts such as a transmission for automobiles, an alloy system (Patent Document 1) for melting and casting using pure metals (Patent Document 1), a method for producing powder by mixing oxides (Patent Document 2) (Zn) and 10% or less of tin (Sn) based on the components of the copper alloy synchronizer ring, regardless of the manufacturing type. Or a non-ferrous metal or powder, or by a combination of oxides. The synchronizer ring manufactured by melt casting (Patent Document 1) shows a limit to the weight reduction of parts because it shows a single structure rather than a dual structure made of dissimilar metals. In the case where the synchronizer ring is manufactured by a method in which powders and oxides are mixedly added (Fe ₂ O ₃ ) _and oxides (SiO _{2 ,} Al ₂ O ₃ ) have a limitation in that sintering is reduced during sintering to decrease the pore distribution and bonding force and decrease the mechanical properties

Korean Patent Publication No. 10-2008-0080156 US Patent 5324592 Korean Patent Publication No. 10-2013-0002584

DISCLOSURE Technical Problem Accordingly, the present invention has been made in order to overcome the limitations of the prior art described above, and it is an object of the present invention to provide a method of manufacturing a copper alloy sintered alloy by forming a fine dispersed phase (oxide) having a size of 0.05 to 20 nm in a matrix by using a selective oxidation process Uniform distribution, thereby having excellent bonding strength, having no defect in the interface between the metal base material and the dissimilar metal coating layer, and moreover, the coating layer can be uniformly formed to improve the forming processability and improve the process efficiency, And a method of manufacturing a friction machine member having a double structure excellent in abrasion resistance.

The present invention effectively provides a dual structure part having excellent high temperature strength and abrasion resistance suitable for manufacturing a worm wheel, a bearing, a slipper for a compressor, and other high-speed parts for automotive transmission parts and general machinery requiring high friction characteristics and abrasion resistance can do.

Further, the technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems which are not mentioned can be understood from the following description in order to clearly understand those skilled in the art to which the present invention belongs .

According to an aspect of the present invention,

By weight, zinc (Zn): more than 15% and not more than 20%; Tin (Sn): 5 to 10%; At least one of aluminum (Al): 0.01 to 2%, silicon (Si): 0.01 to 2%, and titanium (Ti): 0.01 to 2%; Phosphorus (P): not more than 0.1% (excluding 0%); Providing a copper alloy powder containing Cu as a remainder and then coating the surface of the metal base material to form a coating layer;

The metal base material on which the coating layer is formed is maintained at 700 to 800 ° C for 10 to 40 minutes to selectively oxidize to form at least one nano-sized fine second phase oxide selected from Al ₂ O ₃ , SiO ₂ and TiO ₂ in the coating layer Thereby uniformly distributing it;

Sintering the coating layer in which the second phase oxides are distributed at 760 to 880 캜 for 10 to 40 minutes under a reducing atmosphere so as to prevent changes in copper oxidation and alloy components, thereby integrating the coating layer with the metal base material; And

And a step of forming a mechanical part of a predetermined shape by molding the metal base material in which the coating layer is integrated, to a method of manufacturing a friction material having a double structure having high strength and high abrasion resistance at high temperature.

The copper alloy powder preferably contains zinc in a range of 15.5 to 17.5%.

The copper alloy powder preferably contains nickel (Ni) in a range of 0.1 to 3.0%.

The copper alloy powder preferably contains iron in a range of 0.1 to 3%.

The copper alloy powder preferably contains manganese (Mn) in a range of 0.1 to 3%.

The copper alloy powder preferably further comprises silver (Ag) in a range of 0.1 to 2%.

In the present invention, it is preferable to use a multi-step gradual molding process in the molding process.

The present invention having the above-described constitution is characterized by forming a fine second phase (oxide) such as nano-sized Al ₂ O ₃ , SiO ₂ and TiO ₂ in a selective oxidation process for producing a copper alloy sintered body, (P) is reacted with oxygen during the sintering process to form an optimal sintering atmosphere to prevent oxidation of copper, thereby promoting the sintering process. have.

It is also possible to maintain the composition ratio of the copper alloy-based alloy component by suppressing the evaporation of the alloy element having a low boiling point, to increase the solubility of nickel (Ni) and tin (Sn) and to improve the mechanical properties, It is possible to provide worm wheels and bearings, slippers for compressors, and other high-speed motion parts for high-quality automotive transmission parts and general machinery with high friction and wear resistance.

FIG. 1 is a process flow diagram for explaining a manufacturing process of a dual-structure high-strength wear-resistant alloy in which a nano-sized fine second phase (oxide) is uniformly distributed in a matrix using a selective oxidation process according to the present invention.
FIG. 2 is a schematic view showing the microstructure of a dual-structure high-strength wear-resistant alloy in which a nano-sized fine second phase (oxide) is uniformly distributed in a matrix using a selective oxidation process according to the present invention.

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

A method for producing a friction machine member having a dual structure having high strength and high abrasion resistance at high temperature according to the present invention is characterized by containing zinc (Zn): more than 15% and less than 20%; Tin (Sn): 5 to 10%; At least one of aluminum (Al): 0.01 to 2%, silicon (Si): 0.01 to 2%, and titanium (Ti): 0.01 to 2%; Phosphorus (P): not more than 0.1% (excluding 0%); Providing a copper alloy powder containing Cu as a remainder and then coating the surface of the metal base material to form a coating layer; The metal base material on which the coating layer is formed is maintained at 700 to 800 ° C for 10 to 40 minutes to selectively oxidize to form at least one nano-sized fine second phase oxide selected from Al ₂ O ₃ , SiO ₂ and TiO ₂ in the coating layer Thereby uniformly distributing it; Sintering the coating layer in which the second phase oxides are distributed at 760 to 880 캜 for 10 to 40 minutes under a reducing atmosphere so as to prevent changes in copper oxidation and alloy components, thereby integrating the coating layer with the metal base material; And a step of manufacturing a mechanical part of a predetermined shape by molding the metal base material in which the coating layer is integrated.

FIG. 1 is a process flow diagram for explaining a manufacturing process of a dual-structure high-strength wear-resistant alloy in which a nano-sized fine second phase (oxide) is uniformly distributed in a matrix using a selective oxidation process according to the present invention.

First, in the present invention, zinc (Zn) is contained in an amount of more than 15% but not more than 20% by weight, Tin (Sn): 5 to 10%; At least one of aluminum (Al): 0.01 to 2%, silicon (Si): 0.01 to 2%, and titanium (Ti): 0.01 to 2%; Phosphorus (P): not more than 0.1% (excluding 0%); Copper alloy powder containing Cu as a remainder is prepared and then coated on the surface of the metal base material to form a coating layer.

That is, first, a plate-shaped base material in the form of a steel disc is provided and the contaminants present on the surface of the steel base material are cleaned. Cleaning of the base material is a step of removing substances that interfere with the bonding between the base material and the dissimilar metals during sintering such as various organic substances, foreign matter and dust on the surface of the base material, and it is wiped with a cleaning agent or wiped with a steam brush or the like. On the other hand, it is preferable to use an iron-based alloy as the base material.

Next, the copper alloy powder to be used as the dual structure covering material is quantified and mixed so as to have a uniform composition, and the copper alloy alloy powder to form a coating layer on the washed base material is laminated on the surface of the base material to a uniform thickness.

The compositions and composition ratios of the coating layers that can form the worm wheels, bearings, slippers for compressors, and other high-speed moving parts for automotive transmission parts and general machinery with double structure are as follows.

In the present invention, the composition of the copper alloy system powder is, by weight, more than 15% and not more than 20% of zinc (Zn); Tin (Sn): 5 to 10%; At least one of aluminum (Al): 0.01 to 2%, silicon (Si): 0.01 to 2%, and titanium (Ti): 0.01 to 2%; Phosphorus (P): not more than 0.1% (excluding 0%); And the balance Cu. That is, in the present invention, the copper alloy forming the double-layer coating layer may be copper, zinc, tin, aluminum, titanium and / or silicon, . ≪ / RTI >

At this time, the content of zinc (Zn) in the composition of the copper alloy powder is preferably more than 15% to 20% by weight, more preferably 15.5 to 17.5% by weight. The zinc (Zn) serves to improve the mechanical properties of the coating layer. When the content is too high, the hardness is high, thereby accelerating the abrasion of the contact parts to be contacted to deteriorate the performance. On the other hand, when the content is too low, The copper alloy coating layer may be easily worn out.

The tin (Sn) serves to increase the strength of the coating layer, and the ratio is preferably 5 to 10%, more preferably 5 to 8.5%.

The proportion of phosphorus (P) is preferably 0.1% or less, more preferably 0.05% or less. This phosphorus (P) improves the sintering atmosphere by reducing the oxygen in the sintering furnace during sintering and reduces the evaporation of the alloying element having a low boiling point during the sintering process, thereby facilitating the control of the zinc component, The sintered coating layer can exhibit high friction characteristics and wear resistance because the solubility of tin (Sn) is increased and the mechanical properties are increased. However, when phosphorus is added in an excessive amount, the physical properties of the coating layer are weakened and the strength of the coating layer is lowered.

The aluminum (Al) serves to improve the mechanical properties of the coating layer by forming an intermetallic compound. The ratio is preferably from 0.01 to 3%, more preferably from 0.1 to 2.0%.

The amount of titanium (Ti) is preferably 0.01 to 3%, more preferably 0.1 to 2.0%.

The silicon (Si) is preferably 0.01 to 3%, more preferably 0.1 to 2.0%.

In the present invention, the iron (Fe) and the manganese (Mn) serve to increase the strength of the coating layer, and the ratio thereof is preferably 0.1 to 3%, more preferably 0.1 to 2.0% will be.

Meanwhile, the copper alloy powder of the present invention preferably further comprises silver (Ag).

In the present invention, silver (Ag) improves the strength and increases the thermal conductivity to improve the wear resistance of the worm wheel, bearings, slippers for compressors, and other high-speed parts for automobile transmission parts and general machinery . In the present invention, the silver (Ag) ratio is preferably 0.1 to 2%, more preferably 0.1 to 0.5%.

In the present invention, the metal base material having the coating layer formed thereon is maintained at 700 to 800 ° C for 10 to 40 minutes to selectively oxidize the metal base material. Thus, at least one nano-sized fine material selected from Al ₂ O ₃ , SiO ₂ and TiO ₂ 2-phase oxide is formed and uniformly distributed.

That is, when the metal base material on which the coating layer is formed is selectively oxidized at 700 to 800 ° C. for 10 to 40 minutes, aluminum (Al), silicon (Si), titanium (Ti) Al ₂ O ₃ , SiO ₂ , and TiO ₂ , which are fine second phases (oxides) having a size of 20 nm, are formed and uniformly dispersed in the matrix.

That is, the copper alloy powder is uniformly deposited on the surface of the metal base material, and then is selectively oxidized after being put into a continuous sintering furnace or a general furnace. In this selective oxidation process, The alloy element is subjected to high-temperature heat so as to form a fine dispersed phase (oxide) having a size of 0.05 to 20 nm.

Preferable process conditions for the selective oxidation process are controlled at a selective oxidation temperature of 700 to 800 DEG C and a selective oxidation time of 10 to 40 minutes.

In the present invention, the metallic base material and the coating layer are integrated by sintering at 760 to 880 ° C for 10 to 40 minutes in a reducing atmosphere so as to prevent copper oxidation and alloy composition changes of the copper alloy powder constituting the coating layer.

That is, after the selective oxidation step, high-temperature heat is applied to the metal base material in which the copper alloy powder is laminated in the protective atmosphere so that the copper alloy powder constituting the coating layer in the continuous sintering furnace or general furnace is not oxidized, (Copper alloy powder).

Preferable conditions for carrying out such a sintering process include sintering temperature: 760 to 880 DEG C, sintering time: 10 to 40 minutes, atmosphere: reducing atmosphere.

At this time, when the copper alloy powder of the present invention is sintered under the protective gas atmosphere using the metal base material in which the copper alloy powder is uniformly laminated, the content of the alloy element Zn having a low boiling point evaporated during the sintering process can be prevented And the composition ratio of the copper alloy powder composition component can be maintained even after sintering. In addition to uniformly forming the powder coating layer, it also improves the mechanical properties of the sintered coating layer by forming a good interface bonding force, thereby improving the friction characteristics and durability of worm wheels and bearings, slippers for compressors and other high- Can be greatly improved.

In the present invention, a mechanical part of a predetermined shape is manufactured by molding the metal base material in which the coating layer is integrated.

When sintering is completed in the above-described sintering process, the sintered body is taken out from the sintering furnace and put into a molding die. By applying a multi-step gradual molding process, worm wheels and bearings for slippage and bearings for compressors, Completes high-speed motion parts. That is, since the sintered coating layer of the copper alloy powder can be prevented from being damaged when the multi-step gradual forming process is used, it is possible to prevent deterioration of the sintered coating layer due to damage to the sintered coating layer.

In order to prevent the damage of the sintered coating layer of the worm wheel, the bearing, the slipper for the compressor, and the other high-speed movement parts for automobile transmission parts or general machinery during the multi-step gradual molding step, It is desirable to carry out the molding process after covering and protecting.

If the molding process is carried out by the conventional method, the damage of the sintered copper alloy layer directly in contact with the mold is inevitably accompanied. Damage to the copper alloy sintered layer in the manufacturing process affects mechanical properties and degrades the friction coefficient and abrasion resistance, thereby degrading the quality of automotive transmission components. In the present invention, a multi-step gradual forming process is used as a method for preventing the damage of the sintered copper alloy layer in the manufacturing process of the worm wheel, the bearing, the slipper for the compressor, and other high-speed moving parts for automobile transmission parts and general machines having double structure. And a method of molding by using this method is proposed. The sintered body having a dual structure can be preserved in its original shape even after completion of the process after the sintered layer protecting treatment is performed in each molding step. In other words, when the sintered layer is preserved in a circular shape without damage after completion of the process, high mechanical properties and physical properties are maintained, so that a high-quality and high-performance double-layered automobile transmission parts, worm wheels and bearings, slippers for compressors, It is possible to manufacture parts for general machines such as parts for machines.

In the present invention, after the above-described molding step, a heat-treating step for imparting mechanical properties of the manufactured parts can be additionally provided.

Hereinafter, the present invention will be described in detail by way of examples.

(Example)

The contaminants existing on the surface of the iron-based metal base material having the composition components shown in Table 1 were washed. Next, the copper alloy powder having the composition shown in Table 2 below was quantified and mixed so as to have a uniform composition, and then laminated on the surface of the metal base material to have a uniform thickness. Thereafter, a selective oxidation process is performed for 10 to 40 minutes at a temperature of 700 to 800 ° C. on a part of the metal base materials in which the copper alloy powder is laminated to obtain a fine second phase (Oxides) Al ₂ O ₃ and SiO ₂ were formed and uniformly dispersed in the matrix. For comparison, the above-described selective oxidation process was not performed on the other metal base materials.

The sintering was performed at a sintering temperature of 870 ° C., a sintering time of 20 minutes, and an atmosphere of 75% N ₂ + 25% H ₂ And controlled in a reducing atmosphere.

After the sintering was completed, the sintered body was taken out from the sintering furnace, and then put into a molding die, and then a multi-step gradual molding step was applied to manufacture an automotive transmission part.

Base material composition (% by weight) Metal base material
C Si Mn P S Fe 0.32 to 0.38 0.15-0.35 0.60 to 0.90 0.03 or less 0.035 or less Remainder

division
Copper alloy powder composition ratio (% by weight) Zn Sn Al Si P Ag Mn Fe C Pb Ni Co Ti Al ₂ O ₃ SiO ₂ Cu Example 1 15.5 5.0 0.1 0.1 Remainder Example 2 15.5 5.0 0.1 0.1 Remainder Example 3 15.5 5.0 0.1 0.1 0.5 Remainder Example 4 15.5 5.0 0.1 0.1 0.1 0.5 Remainder Example 5 15.5 5.0 0.1 0.1 0.1 Remainder Comparative Example 1 10 to 15 4.0 to 7.0 0 to 0.3 Remainder Comparative Example 2 Remainder 0 to 3.0 0.1 to 8.0 0.3 to 5.0 0 to 0.02 0.5 to 8.0 0.5 to 3.5 0 to 0.01 0 to 5.0 0 to 0.1 0 to 0.05 Comparative Example 3 30 3.5 to 6.5 18-22 4.0 to 6.0 4.0 to 6.0 0.5 to 1.5 Remainder

division
Whether or not the selective oxidation process is used
The second phase oxide Types of oxides Size (nm) Example 1 O Al ₂ O ₃ 0.05 to 20 Example 2 O SiO ₂ 0.05 to 20 Example 3 O Al ₂ O ₃ 0.05 to 20 Example 4 O Al ₂ O ₃ + SiO ₂ 0.05 to 20 Example 5 O Al ₂ O ₃ + SiO ₂ 0.05 to 20 Comparative Example 1 X - - Comparative Example 2 X - - Comparative Example 3 X - -

As shown in Table 2-3, aluminum (Al) is added as an alloy element forming the second phase, and Al ₂ O ₃ , which is a fine dispersed phase of 0.05 to 20 nm in size, is formed as a second phase through a selective oxidation process In Example 1, uniformly distributed in the matrix, the hardness was measured at 150 Hv.

Further, silicon (Si) was added as an alloy element forming the second phase, and SiO ₂ , which is a fine dispersed phase of 0.05 to 20 nm in size, was formed as a second phase through a selective oxidation process, and Example 2, Was measured at 140 Hv.

In addition, aluminum (Al) and silicon (Si) are added singly or in combination as an alloy element forming the second phase, silver (Ag) is added, and a selective oxidation process is performed to form a second phase, In the case of Singitae 3-4 in which the trader Al ₂ O ₃ or SiO ₂ was homogeneously distributed uniformly or complexly, the hardness was measured as 170-210 Hv.

Aluminum (Al) and silicon (Si) were added in combination and Al ₂ O ₃ and SiO _{2, which} are fine dispersion phases of 0.05 to 20 nm in size, Showed a hardness value of 195 Hv.

On the other hand, in the case of the automotive transmission component of Example 1-5, the coefficient of friction initially showed a level of about 0.10 after rotation only at 0.12 level.

That is, the composition ratio of the copper alloy powder composition component is maintained in the sintering process and the selective oxidation process is performed to form a fine dispersed phase (oxide) having a size of 0.05 to 20 nm in the matrix and uniformly distributed. It is possible to manufacture a friction machine member having a double structure having high friction characteristics and wear resistance.

On the contrary, Comparative Example 1 showed a problem of low wear resistance due to a low zinc (Zn) content and a hardness of 70 Hv, which was lower than that of the Examples. In the case of Comparative Example 2-3, by mixing the high melting point alloy element or the oxide powder together with the copper alloy powder, the bonding force between the alloying elements during sintering and the sintering property were deteriorated, which was a factor for inhibiting the abrasion resistance.

FIG. 2 (b) is a schematic view showing the microstructure of a dual-structure high-strength wear-resistant alloy in which a nano-sized fine second phase (oxide) dispersed phase is uniformly distributed in a matrix using a selective oxidation process according to the present invention 2 (a) in which the selective oxidation process is not used and the dispersed phase as the second phase.

While the present invention has been particularly shown and described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of course, this is possible. Accordingly, the scope of the present invention should not be limited to the described embodiments, but should be defined by the following claims as well as equivalents thereof

Claims (8)

By weight, zinc (Zn): more than 15% and not more than 20%; Tin (Sn): 5 to 10%; At least one of aluminum (Al): 0.01 to 2%, silicon (Si): 0.01 to 2%, and titanium (Ti): 0.01 to 2%; Phosphorus (P): not more than 0.1% (excluding 0%); Providing a copper alloy powder containing Cu as a remainder and then coating the surface of the metal base material to form a coating layer;
The metal base material on which the coating layer is formed is maintained at 700 to 800 ° C for 10 to 40 minutes to selectively oxidize to form at least one nano-sized fine second phase oxide selected from Al ₂ O ₃ , SiO ₂ and TiO ₂ in the coating layer Thereby uniformly distributing it;
Sintering the coating layer in which the second phase oxides are distributed at 760 to 880 캜 for 10 to 40 minutes under a reducing atmosphere so as to prevent changes in copper oxidation and alloy components, thereby integrating the coating layer with the metal base material; And
And a step of forming a metal base material in which the coating layer is integrated to produce a mechanical part of a predetermined shape.
The method according to claim 1, wherein the copper alloy powder comprises zinc (Zn) in a range of 15.5 to 17.5%.
The method according to claim 1, wherein the copper alloy powder further comprises nickel (Ni) in a range of 0.1 to 3.0%.
The method according to claim 1, wherein the copper alloy powder further comprises iron (Fe) in a range of 0.1 to 3%.
The method according to claim 1, wherein the copper alloy powder further comprises manganese (Mn) in a range of 0.1 to 3%.
The method according to claim 1, wherein the copper alloy powder further comprises silver (Ag) in a range of 0.1 to 2%.
The method of claim 1, wherein the forming step uses a multi-step gradual forming step.
The method according to claim 1, wherein the size of the second phase oxide ranges from 0.05 to 20 nm.

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