Copper-nickel-silicon-manganese (Cu-Ni-Si-Mn) alloy containing phase G and method for producing the same

Abstract

The present invention provides a copper-nickel-silicon-manganese alloy containing a G phase and a method for producing the same. [Solution] The present invention relates to a copper-nickel-silicon-manganese alloy in which manganese is added to form a G phase at the grain boundaries of the alloy, thereby reducing inclusions and providing excellent strength and wear resistance while also improving economy, and a method for producing the same.

Description

[Technical Field]

[0001] This invention relates to a copper-nickel-silicon-manganese alloy containing a G-phase and a method for producing the same. More specifically, this invention relates to a copper-nickel-silicon-manganese alloy and a method for producing the same, in which manganese is added to form a G-phase at the grain boundaries of the alloy, thereby reducing inclusions and improving economic efficiency while possessing excellent strength and wear resistance. [Background technology]

[0002] Copper alloys are widely used in electrical and electronic components due to their high strength and electrical conductivity. Among these, copper-beryllium (Cu-Be) alloys have been widely used in various electrical and electronic components such as lead frames and connectors, as a representative precipitation-hardening copper alloy with a wide range of strengths and conductivity. However, copper-beryllium alloys are expensive, easily oxidized, and harmful to the environment and human health due to the toxicity of beryllium during processing. Currently, many countries are avoiding the manufacture of copper-beryllium alloys. Therefore, there has been a continuing demand for the development of copper alloys with high strength and conductivity that can replace copper-beryllium alloys.

[0003] Furthermore, in recent years, with the increasing use of wear-resistant parts in automobiles, there has been a demand for alternative copper alloys with improved strength and wear resistance to suit the environment of automobile parts subjected to repeated vibration and friction. To replace the above-mentioned copper-beryllium alloys, copper-nickel-silicon (Cu-Ni-Si) alloys have come into use.

[0004] Copper-nickel-silicon alloys are precipitation-hardening copper alloys that possess superior strength, electrical conductivity, and bendability compared to other copper alloys. They are widely used as materials for lead frames, connectors, and other components, and are currently one of the alloys being extensively developed. Such copper-nickel-silicon alloys can improve strength and electrical conductivity by precipitating fine nickel-silicon (Ni-Si) intermetallic compound particles from a copper matrix. However, as the amount of nickel and silicon added increases, inclusions are formed, reducing strength and ductility. Therefore, there is a need to develop copper-nickel-silicon alloys that can effectively reduce these inclusions.

[0005] Furthermore, copper-nickel-silicon alloys are age-hardening alloys that require solution treatment and long-term aging, but these processes can be economically unfeasible. Therefore, there is a need to develop copper-nickel-silicon alloys that can improve both the physical properties of copper alloys and their economic viability.

[0006] As background technology for the present invention, Korean Registered Patent No. 10-1627696 [Patent Document 1] discloses a copper alloy material for automobiles and electrical and electronic components and a method for manufacturing the same. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Korean Registered Patent Publication No. 10-1627696 [Overview of the project] [Problems that the invention aims to solve]

[0008] The object of the present invention is to provide a copper-nickel-silicon alloy in which inclusions are reduced by forming new compounds at the grain boundaries, and a method for producing the same.

[0009] Another object of the present invention is to provide a copper-nickel-silicon alloy and a method for producing the same, in which new compounds are formed at the grain boundaries, thereby improving the mechanical properties of the alloy, such as strength and wear resistance, and reducing the amount of inclusions.

[0010] Another object of the present invention is to provide a copper-nickel-silicon alloy and a method for producing the same, in which the processability of the alloy is improved and inclusions are reduced by forming new compounds at the grain boundaries.

[0011] Another object of the present invention is to provide a method for producing a copper-nickel-silicon alloy with reduced inclusions, which can reduce the number of solution treatment and aging treatment steps.

[0012] Further objectives and advantages of the present invention will become clearer through the following detailed description of the invention, claims, and drawings. [Means for solving the problem]

[0013] According to one aspect of the present invention, a copper-nickel-silicon (Cu-Ni-Si) alloy with manganese (Mn) added, wherein Mn6Ni is present at the grain boundaries in the alloy. 16 A copper-nickel-silicon-manganese alloy is provided, characterized by containing a Si7 phase (G phase).

[0014] According to one embodiment of the present invention, the copper-nickel-silicon-manganese alloy may contain, with respect to its total weight, 2 to 6% by weight of nickel (Ni); 0.5 to 2% by weight of silicon (Si); 0.5 to 2.5% by weight of manganese (Mn); and copper (Cu) with the remainder of unavoidable impurities.

[0015] According to one embodiment of the present invention, the copper-nickel-silicon-manganese alloy may contain 0.7 to 2.2% by weight of manganese (Mn) relative to its total weight.

[0016] According to one embodiment of the present invention, the copper-nickel-silicon-manganese alloy may contain 0.5 to 1.5% by weight of silicon (Si) relative to its total weight.

[0017] According to one embodiment of the present invention, the copper-nickel-silicon-manganese alloy can have a content ratio of manganese (Mn) to nickel (Ni), Mn / Ni, of 0.08 to 1.3.

[0018] According to one embodiment of the present invention, the copper-nickel-silicon-manganese alloy can have a content ratio of the total of manganese (Mn) and nickel (Ni) to silicon (Si), (Mn + Ni) / Si, of 1.2 to 18.

[0019] According to one embodiment of the present invention, the copper-nickel-silicon-manganese alloy can have a content ratio of nickel (Ni) to silicon (Si), Ni / Si, of 0.9 to 13.

[0020] According to one embodiment of the present invention, the copper-nickel-silicon-manganese alloy can be formed by homogenization treatment.

[0021] According to one embodiment of the present invention, the copper-nickel-silicon-manganese alloy can have a tensile strength of 830 to 1200 MPa.

[0022] According to one embodiment of the present invention, the copper-nickel-silicon-manganese alloy can reduce inclusions in the alloy and increase the wear resistance and elongation of the alloy.

[0023] According to another aspect of the present invention, i) casting a copper-nickel-silicon-manganese alloy containing 2 to 6 wt% nickel (Ni); 0.5 to 2 wt% silicon (Si); 0.5 to 2.5 wt% manganese (Mn); and the balance of copper (Cu) and inevitable impurities, based on the total weight of the alloy; and ii) homogenizing the cast copper-nickel-silicon-manganese alloy; are included, and a method for manufacturing a copper-nickel-silicon-manganese alloy with reduced inclusions is provided.

[0024] According to one embodiment of the present invention, the homogenization treatment in step ii) may be carried out at a temperature of 900°C to 1100°C.

[0025] According to one embodiment of the present invention, the method for producing the copper-nickel-silicon-manganese alloy of the present application may further include: iii) rolling the homogenized copper-nickel-silicon alloy; and iv) aging the rolled copper-nickel-silicon alloy.

[0026] According to one embodiment of the present invention, the rolling in step iii) may be carried out by cold rolling of 85% to 95%.

[0027] According to one embodiment of the present invention, the aging treatment in step iv) may include being carried out at 350°C to 450°C for 1 to 15 minutes.

[0028] According to one embodiment of the present invention, Mn6Ni is present at the grain boundaries in the manufactured copper-nickel-silicon-manganese alloy. 16 It can be characterized by the formation of the Si7 phase (G phase).

[0029] According to one embodiment of the present invention, the copper-nickel-silicon-manganese alloy produced by the manufacturing method of the present invention may have a manganese (Mn) to nickel (Ni) content ratio Mn / Ni of 0.08 to 1.3.

[0030] According to one embodiment of the present invention, the copper-nickel-silicon-manganese alloy produced by the manufacturing method of the present invention may have a content ratio (Mn+Ni) / Si of 1.2 to 18, which is the sum of manganese (Mn) and nickel (Ni) to silicon (Si).

[0031] According to one embodiment of the present invention, the copper-nickel-silicon-manganese alloy produced by the manufacturing method of the present invention may have a nickel (Ni) to silicon (Si) content ratio (Ni / Si) of 0.9 to 13. [Effects of the Invention]

[0032] According to one embodiment of the present invention, manganese (Mn) is added to form Mn6Ni at the grain boundaries. 16 This allows for the formation of a Si7 phase (G phase) and a reduction in copper-nickel-silicon alloy inclusions.

[0033] According to one embodiment of the present invention, manganese (Mn) is added to form Mn6Ni at the grain boundaries. 16 By forming the Si7 phase (G phase), the mechanical properties of the copper-nickel-silicon alloy, including its strength and wear resistance, can be improved.

[0034] According to one embodiment of the present invention, manganese (Mn) is added to form Mn6Ni at the grain boundaries. 16 This allows for the formation of a Si7 phase (G phase), improving the workability of copper-nickel-silicon alloys.

[0035] According to one embodiment of the present invention, in the manufacturing process of a copper-nickel-silicon alloy with manganese (Mn) added, a homogenization treatment can be performed instead of a solution treatment, thereby reducing the solution treatment and aging treatment steps and improving the economic efficiency of the manufacturing process. [Brief explanation of the drawing]

[0036] [Figure 1] This figure shows the effect of manganese (Mn) addition on reducing inclusions in copper-nickel-silicon alloys. [Figure 2] This graph shows the manufacturing process of a copper-nickel-silicon alloy to confirm the formation of discontinuous precipitates during aging after solution treatment. [Figure 3] This figure shows discontinuous precipitates during aging after solution treatment of a copper-nickel-silicon alloy without manganese (Mn) added. [Figure 4] This figure shows discontinuous precipitates during aging after solution treatment of a copper-nickel-silicon alloy with manganese (Mn) added. [Figure 5] This graph shows the hardness of copper-nickel-silicon alloys after solution treatment, depending on the presence or absence of manganese (Mn) addition, based on aging time. [Figure 6] This figure shows discontinuous precipitates in copper-nickel-silicon alloys depending on the presence or absence of manganese (Mn) addition and the aging time. [Figure 7] This figure shows the grain boundary structure of copper-nickel-silicon alloys with and without manganese (Mn) addition and with different aging times. [Figure 8] This figure shows compounds formed at the grain boundaries of a copper-nickel-silicon alloy without manganese (Mn) added. [Figure 9] This figure shows compounds formed at the grain boundaries of a copper-nickel-silicon alloy with manganese (Mn) added. [Figure 10] This figure shows the precipitates of copper-nickel-silicon alloys with and without the addition of manganese (Mn). [Figure 11] This graph shows the average size of precipitates in copper-nickel-silicon alloys with and without manganese (Mn) addition and with different aging times. [Figure 12] This graph shows the manufacturing process of a copper-nickel-silicon alloy, including solution treatment, according to one embodiment of the present invention. [Figure 13] This graph shows the manufacturing process of a copper-nickel-silicon alloy, including a homogenization treatment, according to one embodiment of the present invention. [Figure 14] This graph shows the hardness and conductivity of a copper-nickel-silicon alloy according to one embodiment of the present invention, based on the aging treatment time after solution treatment or homogenization treatment. [Figure 15] This is an X-ray analysis graph of a manganese (Mn)-added copper-nickel-silicon alloy according to one embodiment of the present invention. [Figure 16] This figure shows the compounds formed at the grain boundaries during homogenization treatment according to one embodiment of the present invention, depending on whether or not manganese (Mn) is added. [Figure 17] This figure shows compounds formed at grain boundaries and sub-grain boundaries depending on whether or not manganese (Mn) is added during homogenization treatment according to one embodiment of the present invention. [Figure 18]This graph shows the mechanical properties of a copper-nickel-silicon alloy during casting and homogenization treatment according to one embodiment of the present invention. [Figure 19] This graph shows the mechanical properties of a copper-nickel-silicon alloy after homogenization treatment, rolling, and aging treatment according to one embodiment of the present invention. [Figure 20] This graph shows the manufacturing process of a copper-nickel-silicon alloy according to one embodiment of the present invention. [Figure 21] This is a graph showing the tensile strength-stretch ratio of a copper-nickel-silicon alloy according to one embodiment of the present invention. [Figure 22] This is a tensile strength-conductivity graph of a copper-nickel-silicon alloy according to one embodiment of the present invention. [Figure 23] This graph shows the manganese content and tensile strength of a copper-nickel-silicon alloy according to one embodiment of the present invention, based on the processing and heat treatment steps. [Figure 24] This graph shows the amount of manganese added to a copper-nickel-silicon alloy according to one embodiment of the present invention, and the elongation rate due to the processing heat treatment process. [Figure 25] This graph shows the manganese content and conductivity of a copper-nickel-silicon alloy according to one embodiment of the present invention, based on the processing and heat treatment steps. [Figure 26] This graph shows the tensile strength of a copper-nickel-silicon alloy based on its Mn / Ni value, according to one embodiment of the present invention. [Figure 27] This graph shows the manufacturing process of a copper-nickel-silicon alloy for measuring the coefficient of friction according to one embodiment of the present invention. [Figure 28] This is a schematic diagram of a friction coefficient measurement test using one embodiment of the present invention. [Figure 29] This graph shows the results of a friction coefficient measurement test for a copper-nickel-silicon alloy according to one embodiment of the present invention. [Figure 30] This graph shows the results of a wear test on a copper-nickel-silicon alloy using one embodiment of the present invention. [Modes for carrying out the invention]

[0037] Because the present invention can be subjected to various transformations and has various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, but should be understood as including all transformations, equivalents, and substitutes that fall within the spirit and technical scope of the present invention. In describing the present invention, if it is determined that a specific description of the relevant prior art would obscure the gist of the invention, such detailed description will be omitted.

[0038] The terms used herein are used solely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as “includes” or “having” should be understood as specifying the presence of features, figures, stages, actions, components, parts, or combinations thereof described herein, and not as preemptively excluding the possibility of the presence or addition of one or more other features, figures, stages, actions, components, parts, or combinations thereof.

[0039] The copper-nickel-silicon alloy with reduced inclusions according to the present invention and its manufacturing method will be described in detail below with reference to the attached tables and drawings.

[0040] According to one aspect of the present invention, a copper-nickel-silicon (Cu-Ni-Si) alloy with manganese (Mn) added, wherein Mn6Ni is present at the grain boundaries in the alloy. 16 A copper-nickel-silicon-manganese alloy is provided, characterized by containing a Si7 phase (G phase).

[0041] Copper-nickel-silicon alloy is a typical precipitation-hardening copper alloy, characterized in that fine nickel-silicon (Ni-Si) based intermetallic compound particles such as Ni2Si are precipitated in a copper matrix, improving strength and electrical conductivity. However, the inventors have found that adding manganese to the copper-nickel-silicon alloy can reduce inclusions and improve mechanical properties such as strength and wear resistance and workability. Further, the inventors have confirmed that Mn6Ni 16 Si7 phase (G phase) is formed at the grain boundaries in the alloy, and provide a copper-nickel-silicon-manganese alloy with reduced inclusions, excellent strength and wear resistance, and improved economy.

[0042] Although not limited thereto, it can include 2 to 6 wt% nickel (Ni); 0.5 to 2 wt% silicon (Si); 0.5 to 2.5 wt% manganese (Mn); and the balance of copper (Cu) and inevitable impurities, based on the total weight of the copper-nickel-silicon-manganese alloy.

[0043] Copper-nickel-silicon alloy is a typical precipitation-hardening copper alloy, characterized in that fine nickel-silicon (Ni-Si) based intermetallic compound particles such as Ni2Si are precipitated in a copper matrix, improving strength and electrical conductivity. However, the inventors have confirmed that Mn6Ni 16 Si7 phase (G phase) is formed, and thereby confirmed that mechanical properties and workability are improved.

[0044] Nickel (Ni) is a solid solution hardening element and is known as an element that can form Ni-Si based precipitates and improve the strength and electrical conductivity characteristics of copper alloys. However, in the present application, as manganese (Mn) is added, Mn6Ni 16The formation of the Si7 phase (G phase) can contribute to improving the mechanical properties of the alloy, including its strength and hardness. If the nickel (Ni) content is less than 2% by weight, the above effect may not be sufficient. On the other hand, excess nickel can lead to a decrease in electrical conductivity or a decrease in bendability due to the formation of coarse precipitates, so it is preferable that the nickel content does not exceed 6% by weight.

[0045] Silicon (Si) is an element necessary for the formation of Ni-Si precipitates, which are compounds mainly composed of Ni2Si. It cannot be said that both Ni and Si in the alloy precipitate through aging treatment; to some extent, they exist in a solid solution state within the matrix. While solid solution Ni and Si improve the strength of the copper alloy, their effect is smaller than that of precipitated Ni and Si, and they can cause a decrease in electrical conductivity. Therefore, the silicon (Si) content is preferably 0.5 to 2% by weight relative to the total weight of the copper-nickel-silicon-manganese alloy. Although not limited to this, the copper-nickel-silicon-manganese alloy is even more preferable for improving mechanical properties and workability if it contains 0.5 to 1.5% by weight of silicon (Si) relative to the total weight of the alloy, and even more preferable if it contains 0.79 to 1.26% by weight.

[0046] Copper-nickel-silicon alloys can increase in strength by increasing the amount of nickel and silicon added, but beyond a certain amount, the increase in strength may saturate.

[0047] Manganese (Mn) can improve the strength, corrosion resistance, and wear resistance of alloys by forming fine compounds with solid solution elements and other elements. Furthermore, when coexisting with nickel (Ni) and silicon (Si) in the alloy matrix structure, it can form intermetallic compounds that improve the wear resistance of the alloy. In this application, as manganese (Mn) is added with copper, nickel, and silicon in appropriate content ratios, Mn6Ni 16The Si7 phase (G phase) is formed, contributing to improvements in the mechanical properties, including strength and hardness, as well as machinability and wear resistance of the alloy. Therefore, a manganese (Mn) content of 0.5 to 2.5% by weight is preferable for improving the mechanical properties, machinability, and wear resistance of the alloy, 0.5 to 2.2% by weight is more preferable, 0.7 to 2.2% by weight is even more preferable, and 0.5 to 2.14% by weight is even more preferable.

[0048] Although not limited thereto, the copper-nickel-silicon-manganese alloy may contain manganese (Mn) and nickel (Ni) such that the manganese (Mn) to nickel (Ni) content ratio Mn / Ni is 0.08 to 1.3. A manganese (Mn) to nickel (Ni) content ratio Mn / Ni of 0.15 to 0.4 is more preferable for improving mechanical properties, workability, and wear resistance, and 0.18 to 0.37 is even more preferable.

[0049] Although not limited thereto, the copper-nickel-silicon-manganese alloy may contain manganese (Mn), nickel (Ni), and silicon (Si) such that the content ratio (Mn+Ni) / Si of the total manganese (Mn) and nickel (Ni) to silicon (Si) is 1.2 to 18. A content ratio (Mn+Ni) / Si of 4 to 6.5 is even more preferable for improving mechanical properties, workability, and wear resistance, and a ratio of 4.17 to 6.45 is even more preferable.

[0050] Although not limited thereto, the copper-nickel-silicon alloy may contain nickel (Ni) and silicon (Si) such that the content ratio of nickel (Ni) to silicon (Si) is 0.9 to 13. A content ratio of nickel (Ni) to silicon (Si) of 3.5 to 5 is more preferable for improving mechanical properties, workability, and wear resistance, and a ratio of 3.54 to 4.76 is even more preferable.

[0051] The aforementioned copper-nickel-silicon-manganese alloy may be formed by a homogenization treatment. Unlike conventional copper-nickel-silicon alloys, the alloy of this application, which is homogenized instead of solution treatment, can ensure mechanical properties such as strength and wear resistance.

[0052] In this case, the tensile strength after homogenization treatment, rolling, and aging treatment can be 830 to 1200 MPa. Although not limited to this, a manganese (Mn) content of 0.7 to 2.15% by weight may be even more suitable for improving mechanical properties, workability, and wear resistance. In this case, the tensile strength after homogenization treatment, rolling, and aging treatment can be 840 to 1100 MPa.

[0053] Furthermore, the homogenization treatment reduces the number of inclusions within the copper-nickel-silicon-manganese alloy, thereby increasing the wear resistance and elongation rate of the alloy.

[0054] According to another aspect of the present invention, a method for producing a copper-nickel-silicon-manganese alloy is provided, comprising the steps of: i) casting a copper-nickel-silicon-manganese alloy containing 2 to 6% by weight of nickel (Ni); 0.5 to 2% by weight of silicon (Si); 0.5 to 2.5% by weight of manganese (Mn); and copper (Cu) with the remainder being unavoidable impurities, based on the total weight of the alloy; and ii) homogenizing the cast copper-nickel-silicon-manganese alloy, wherein inclusions are reduced.

[0055] Although not limited thereto, the homogenization treatment in step ii) may be carried out at 900°C to 1100°C. Although not limited thereto, if the homogenization treatment in step ii) is carried out at a temperature below 900°C, the homogenization effect may be minimal, and if it exceeds 1100°C, the temperature of the alloy may rise excessively and the copper may melt. Although not limited thereto, the homogenization treatment in step ii) is preferably carried out for 7 to 9 hours, and more preferably for 7 hours 30 minutes to 8 hours 30 minutes.

[0056] Although not limited thereto, the method for producing the copper-nickel-silicon-manganese alloy of the present invention may further include: iii) a step of rolling the homogenized copper-nickel-silicon alloy; and iv) a step of aging the rolled copper-nickel-silicon alloy.

[0057] Although not limited thereto, the rolling in step iii) above may include cold rolling at 85% to 95%. Cold rolling is carried out at room temperature and can affect hardness, tensile strength, and workability.

[0058] Although not limited thereto, the aging treatment in step iv) may include being carried out at 350°C to 450°C for 1 to 15 minutes. Although not limited thereto, carrying out the aging treatment in step iv) at 400 to 450°C is preferable as it exhibits the most significant increase in strength due to the formation of intermetallic compounds. If the aging treatment temperature is below 350°C, productivity may decrease sharply as the aging treatment time increases, and if it exceeds 450°C, coarse precipitates may form, reducing the strength of the alloy.

[0059] Although not limited to this, Mn6Ni 16 It can be characterized by the formation of the Si7 phase (G phase).

[0060] Although not limited thereto, the copper-nickel-silicon-manganese alloy produced by the manufacturing method of the present invention may have a manganese (Mn) to nickel (Ni) content ratio Mn / Ni of 0.08 to 1.3.

[0061] Although not limited thereto, the copper-nickel-silicon-manganese alloy manufactured by the manufacturing method of the present invention may have a content ratio (Mn+Ni) / Si of 1.2 to 18 between the total manganese (Mn) and nickel (Ni) content and silicon (Si).

[0062] Although not limited thereto, the copper-nickel-silicon-manganese alloy produced by the manufacturing method of the present invention may have a nickel (Ni) to silicon (Si) content ratio (Ni / Si) of 0.9 to 13.

[0063] [Example of experiment] 1. Manufacturing of copper-nickel-silicon alloy with added manganese (Mn) To confirm the effect of adding manganese (Mn) to the copper-nickel-silicon alloy of the present invention, an alloy having the composition shown in Table 1 below was manufactured.

[0064] Figure 2 is a graph showing the manufacturing process of a copper-nickel-silicon alloy to confirm the formation of discontinuous precipitates during aging after solution treatment. Referring to Figure 2, Alloy 1 and Alloy 2 were prepared by heating and melting the alloy components according to the compositions in Table 1 to create cast specimens, which were then swaged at room temperature until the cross-sectional area reduction rate was 75%. The swaged specimens were subjected to solution heat treatment (SHT) at 980°C for 1 hour, followed by water quenching (WQ), and then aging at 450-550°C for 24 hours. After air cooling (AC) of the aged specimens, the copper-nickel-silicon alloys were produced by drawing them to a cross-sectional area reduction rate of 0-99%.

[0065] [Table 1]

[0066] Figure 3 shows the hardness and discontinuous precipitates during aging after solution treatment of a copper-nickel-silicon alloy without manganese (Mn) addition. Referring to Figure 3, the Cu-4.75Ni-1.13Si alloy (Alloy1) does not show a large change in hardness even with long aging times when the aging temperature is 450°C. On the other hand, when the aging temperature is 500°C and 550°C, the hardness decreases significantly as the aging time increases, and it was confirmed that the hardness decreases particularly rapidly at 500°C. Furthermore, it can be seen that the Cu-4.75Ni-1.13Si alloy (Alloy1) generates more discontinuous precipitates when aged for 12 hours than when aged for 5 hours at 450°C, and a relatively large amount of discontinuous precipitates are generated when aged for 12 hours at 550°C.

[0067] Therefore, it was confirmed that during aging treatment after solution treatment, discontinuous precipitates are formed depending on the aging treatment temperature and time, and that this can reduce hardness.

[0068] Figure 4 shows the hardness and discontinuous precipitates during aging after solution treatment of a copper-nickel-silicon alloy with manganese (Mn) added. Referring to Figure 4, the Cu-4.75Ni-1.13Si-0.71Mn alloy (Alloy2) did not experience a significant decrease in hardness even with long aging times when the aging treatment temperatures were 450°C, 500°C, and 550°C. In particular, it was confirmed that the hardness hardly changed at an aging treatment temperature of 450°C. Furthermore, it can be seen that the Cu-4.75Ni-1.13Si-0.71Mn alloy (Alloy2) showed little formation of discontinuous precipitates with changes in aging temperature and time.

[0069] As a result, we confirmed that adding manganese (Mn) to the copper-nickel-silicon alloy can suppress the formation of discontinuous precipitates during aging treatment, thereby suppressing the decrease in hardness.

[0070] Figure 6 shows the discontinuous precipitates of copper-nickel-silicon alloys with and without manganese (Mn) addition and with different aging times.

[0071] Referring to Figure 6, we can compare the hardness and images of discontinuous precipitates after 3 hours and 24 hours of aging at an aging temperature of 500°C. As a result, even at the same aging temperature and time, the copper-nickel-silicon alloy with manganese (Mn) added showed higher hardness and it was confirmed that the formation of discontinuous precipitates was suppressed.

[0072] Figure 7 shows the grain boundary structure of copper-nickel-silicon alloys with and without manganese (Mn) addition and aging time. Referring to Figure 7, copper-nickel-silicon alloys without manganese (Mn) addition showed slightly larger inclusions at the grain boundaries after 24 hours of aging compared to after 3 hours. On the other hand, copper-nickel-silicon alloys with manganese (Mn) addition showed a significant reduction in inclusions at the grain boundaries after 24 hours of aging compared to after 3 hours. As a result, it was confirmed that the addition of manganese (Mn) can reduce inclusions at the grain boundaries.

[0073] Figure 8 shows compounds formed at the grain boundaries of a copper-nickel-silicon alloy without manganese (Mn) addition.

[0074] Figure 9 shows compounds formed at the grain boundaries of a copper-nickel-silicon alloy with manganese (Mn) added.

[0075] Referring to Figures 8 and 9, in copper-nickel-silicon alloys without manganese (Mn) addition, orthorhombic Ni2Si compounds were observed at the grain boundaries. On the other hand, in copper-nickel-silicon alloys with manganese (Mn) addition, in addition to orthorhombic Ni2Si compounds, cubic Mn6Ni compounds were observed at the grain boundaries. 16 The Si7 phase (G phase) was observed.

[0076] Figure 10 shows the precipitates of copper-nickel-silicon alloy with and without the addition of manganese (Mn).

[0077] Figure 11 is a graph showing the average size of precipitates in copper-nickel-silicon alloys with and without manganese (Mn) addition and aging time.

[0078] Referring to Figure 10, it can be observed that copper-nickel-silicon alloys with manganese (Mn) added form larger precipitates compared to copper-nickel-silicon alloys without manganese (Mn) added.

[0079] Referring to Figure 11, copper-nickel-silicon alloys with manganese (Mn) added formed larger average precipitate sizes compared to copper-nickel-silicon alloys without manganese (Mn), and this difference increased significantly as the aging time increased from 3 hours to 24 hours.

[0080] Therefore, it can be observed that the size of serial precipitates increases as manganese (Mn) is added.

[0081] 2. Manufacturing of copper-nickel-silicon alloy with manganese (Mn) added. The present invention will be described in more detail below through specific examples and comparative examples of the present invention, and the results of their characterization.

[0082] Table 2 below shows the compositions of examples and comparative examples of the present invention. To compare the effects of solution treatment and homogenization treatment of the copper-nickel-silicon alloy of the present invention, and to confirm the effects of rolling and aging treatment after homogenization treatment, copper-nickel-silicon alloys having the compositions shown in Table 2 below were manufactured.

[0083] Examples 1-6 and Comparative Examples 1-4 [Table 2]

[0084] 2-1. Manufacturing of aged copper-nickel-silicon alloy after solution treatment. Figure 12 is a graph showing the manufacturing process of a copper-nickel-silicon alloy, including solution treatment, according to one embodiment of the present invention. Referring to Figure 12, in Examples 1 to 6 and Comparative Examples 1 to 4, test specimens were prepared by heating and melting the alloy components according to the compositions in Table 2, and then subjected to solution treatment at 980°C for 1 hour and water cooling. Subsequently, aging treatment was performed at 500°C for 30 minutes to 6 hours, and the copper-nickel-silicon alloy was produced by air cooling.

[0085] 2-2. Manufacturing of aged copper-nickel-silicon alloy after homogenization treatment.

[0086] Figure 13 is a graph showing the manufacturing process of a copper-nickel-silicon alloy, including homogenization treatment, according to one embodiment of the present invention. Referring to Figure 13, in Examples 1 to 6 and Comparative Examples 1 to 4, the alloy components were heated and melted according to the compositions in Table 2 to prepare test specimens after casting, and then subjected to homogenization treatment at a temperature of 980°C for 1 hour and air cooling. Subsequently, aging treatment was performed at 500°C for 30 minutes to 6 hours, and then air cooled to produce the copper-nickel-silicon alloy.

[0087] 2-3. Effects of aging treatment after solution treatment and homogenization treatment Figure 14 is a graph showing the hardness and conductivity of a copper-nickel-silicon alloy according to one embodiment of the present invention, with respect to aging time after solution treatment or homogenization treatment.

[0088] Referring to Figure 14, the trends in hardness and conductivity based on the aging treatment time after solution treatment or homogenization treatment can be confirmed for Examples 1-5 and Comparative Examples 1-3.

[0089] In Examples 1 (Cu-4Ni-0.84Si-0.7Mn) to 2 (Cu-4Ni-0.84Si-1.42Mn) and Comparative Example 1 (Cu-4Ni-0.84Si), when solution treatment was performed, the hardness tended to increase significantly with aging time and then be maintained. On the other hand, when homogenization treatment was performed, Examples 1 and 2, which had manganese (Mn) added, showed slightly higher hardness than Comparative Example 1, confirming that there was almost no change in hardness with aging time regardless of the presence or absence of manganese (Mn) addition. Furthermore, conductivity was generally higher during homogenization treatment than during solution treatment.

[0090] In Example 3 (Cu-5.31Ni-1.13Si-1.98Mn) and Comparative Example 2 (Cu-5.31Ni-1.13Si), when solution treatment was performed, Example 3, which had manganese (Mn) added, showed a tendency for its hardness to increase significantly with aging time and then be maintained, while Comparative Example 2 showed a slight increase in hardness in the initial stages of aging but then tended to decrease. On the other hand, when homogenization treatment was performed, Example 3, which had manganese (Mn) added, showed a slightly higher hardness than Comparative Example 2, but it could be confirmed that there was almost no change in hardness with aging time regardless of the presence or absence of manganese (Mn) addition. Furthermore, it could be confirmed that conductivity was generally higher during homogenization treatment than during solution treatment.

[0091] In Examples 4 (Cu-6Ni-1.26Si-1.07Mn) to 5 (Cu-6Ni-1.26Si-2.14Mn) and Comparative Example 3 (Cu-6Ni-1.26Si), when solution treatment was performed, Comparative Example 3, which did not contain manganese (Mn), showed a tendency for its hardness to increase slightly in the early stages of aging treatment but then decrease. In contrast, Examples 4 and 5, which contained manganese (Mn), showed a tendency for their hardness to increase significantly with aging treatment time and then be maintained. On the other hand, when homogenization treatment was performed, Examples 4 and 5, which contained manganese (Mn), showed slightly higher hardness than Comparative Example 3, but it could be confirmed that there was almost no change in hardness with aging treatment time regardless of the presence or absence of manganese (Mn) addition. Furthermore, it could be confirmed that electrical conductivity was generally higher during homogenization treatment than during solution treatment.

[0092] As a result, copper-nickel-silicon alloys that were homogenized rather than solution-treated showed almost no change in hardness with aging time, and generally exhibited higher conductivity when homogenized. Furthermore, it was confirmed that adding manganese (Mn) to copper-nickel-silicon alloys resulted in generally higher hardness than when manganese (Mn) was not added, regardless of whether the alloy was solution-treated or homogenized.

[0093] 2-4. Mn6Ni 16 Formation of Si7 phase (G phase)

[0094] Figure 15 is an X-ray analysis graph of a manganese-doped copper-nickel-silicon alloy according to one embodiment of the present invention.

[0095] Referring to Figure 15, the X-ray analysis results of Example 5 (Cu-6Ni-1.26Si-2.14Mn) in which manganese (Mn) was added show that when homogenized, Mn6Ni 16 We confirmed that an Si7 compound was formed. When the homogenization treatment was performed for 1 hour and 8 hours, Mn6Ni was formed in both cases. 16 We confirmed that the Si7 compound was formed, and during the solution treatment, Mn6Ni 16 No Si7 compound formation was confirmed.

[0096] As a result, when manganese (Mn) is added and homogenized, Mn6Ni 16 We confirmed that we can produce Si7 compounds.

[0097] Figure 16 shows the compounds formed at the grain boundaries with and without the addition of manganese (Mn) during homogenization treatment according to one embodiment of the present invention.

[0098] Figure 17 shows the compounds formed at grain boundaries and subgrain boundaries with and without the addition of manganese (Mn) during homogenization treatment according to one embodiment of the present invention.

[0099] Referring to Figures 16 and 17, when homogenized at 980°C for 8 hours, Comparative Example 3 (Cu-6Ni-1.26Si), which does not contain manganese (Mn), has Mn6Ni within the grain boundaries. 16 The Si7 phase was not detected. On the other hand, in Example 5 (Cu-6Ni-1.26Si-2.14Mn), in which manganese (Mn) was added, Mn6Ni was detected at both the main grain boundary and the subgrain boundary. 16 The Si7 phase was detected.

[0100] Table 3 below shows the composition of precipitates at positions 1 to 5 in Figure 17.

[0101] [Table 3]

[0102] 2-5. Mn6Ni 16 Characterization by formation of Si7 phase (G phase) Figure 20 is a graph showing the manufacturing process of a copper-nickel-silicon alloy according to one embodiment of the present invention. Mn6Ni 16To evaluate the properties of copper-nickel-silicon alloys due to the formation of the Si7 phase (G phase), homogenization, rolling, and aging treatments were performed to produce copper-nickel-silicon alloys. According to the composition in Table 2 above, alloy components were heated and melted, and test specimens were prepared after casting. These specimens were then homogenized at 980°C for 8 hours and air-cooled. Cold-rolled with a reduction rate of 95% or less, followed by aging treatment at 400°C for 1 minute, 3 minutes, and 10 minutes, and then air-cooled to produce copper-nickel-silicon alloys.

[0103] Figure 18 is a graph showing the mechanical properties of a copper-nickel-silicon alloy during casting and homogenization treatment according to one embodiment of the present invention.

[0104] Referring to Figure 18, the elongation rates of Example 5 (Cu-6Ni-1.26Si-2.14Mn) and Example 6 (Cu-2.8Ni-0.79Si-0.5Mn), in which manganese (Mn) was added after homogenization treatment, were compared to Comparative Examples 3 (Cu-6Ni-1.26Si) and 4 (Cu- 3.3 It was confirmed that the strength increased significantly compared to Ni-0.79Si. Therefore, it can be confirmed that adding manganese (Mn) to copper-nickel-silicon alloys slightly reduces strength but increases the elongation and improves workability.

[0105] Figure 19 is a graph showing the mechanical properties of a copper-nickel-silicon alloy after homogenization treatment, rolling, and aging treatment according to one embodiment of the present invention.

[0106] Referring to Figure 19, when rolling and aging treatments are performed after homogenization, the elongation rate of the examples with manganese (Mn) added improves with increasing rolling and aging treatment time compared to the comparative examples without manganese (Mn) added, confirming superior processability. Furthermore, while a decrease in strength may occur when manganese (Mn) is added, the decrease in strength is generally not significant, and it can be confirmed that Examples 1, 2, and 5, in which manganese (Mn) amounts of 0.7, 1.42, and 2.14% by weight were added, actually show a significant increase in strength.

[0107] Figure 21 is a graph showing the tensile strength-stretch ratio of a copper-nickel-silicon alloy during rolling and aging treatment after homogenization treatment according to one embodiment of the present invention.

[0108] Figure 22 is a graph showing the tensile strength-conductivity of a copper-nickel-silicon alloy after homogenization treatment, rolling, and aging treatment according to one embodiment of the present invention.

[0109] Referring to Figures 21 and 22, when subjected to aging treatment after homogenization treatment, the examples with manganese (Mn) added tended to have higher tensile strength and / or elongation than the comparative example without manganese (Mn) added. In particular, Examples 1, 2, and 5, in which manganese (Mn) was added at amounts of 0.7, 1.42, and 2.14% by weight, showed simultaneous improvement in both tensile strength and elongation.

[0110] Figure 23 is a graph showing the amount of manganese added to a copper-nickel-silicon alloy according to one embodiment of the present invention, and the tensile strength obtained through processing and heat treatment steps.

[0111] Referring to Figure 23, it can be confirmed that the tensile strength of the examples with manganese (Mn) added is superior to the comparative example without manganese (Mn) added, and that the tensile strength is particularly superior in Examples 1, 2, and 5, where the manganese (Mn) addition amounts are 0.7, 1.42, and 2.14% by weight, respectively. Furthermore, it can be confirmed that the tensile strength is significantly improved when homogenization treatment, rolling, and aging treatment are performed after casting.

[0112] Figure 24 is a graph showing the amount of manganese added to a copper-nickel-silicon alloy according to one embodiment of the present invention and the elongation rate due to the processing heat treatment process.

[0113] Referring to Figure 24, the elongation rate of the examples with manganese (Mn) added tended to be slightly higher than that of the comparative example without manganese (Mn) added. In particular, it can be confirmed that the elongation rate of Example 6, in which the amount of manganese (Mn) added after casting was 0.5% by weight, was remarkably superior. Furthermore, it can be confirmed that the elongation rate improved somewhat when homogenization treatment followed by rolling and aging treatment was performed after casting.

[0114] Figure 25 is a graph showing the conductivity of a copper-nickel-silicon alloy according to one embodiment of the present invention, based on the amount of manganese added and the processing heat treatment steps.

[0115] Referring to Figure 25, the electrical conductivity of the examples with manganese (Mn) added shows a consistent trend compared to the comparative example without manganese (Mn) addition. In particular, it can be confirmed that the electrical conductivity of Example 6, in which the amount of manganese (Mn) added after casting was 0.5% by weight, is remarkably superior. Furthermore, it can be confirmed that the electrical conductivity improves somewhat when homogenization treatment, rolling, and aging treatment are performed after casting.

[0116] Figure 26 is a graph showing the tensile strength of a copper-nickel-silicon alloy according to the Mn / Ni value, based on one embodiment of the present invention.

[0117] Referring to Figure 26, it can be confirmed that in all the examples in which manganese (Mn) was added, the tensile strength was significantly better when the material was rolled and aged after homogenization treatment than when it was rolled and aged after homogenization treatment.

[0118] Table 4 below shows the tensile strength obtained from the processing heat treatment steps of Examples 1, 2, 5, and 6 and Comparative Examples 1, 2, and 4 of the present invention.

[0119] [Table 4]

[0120] Referring to Table 4, the tensile strength of the examples in which manganese (Mn), which significantly increased in tensile strength during rolling and aging treatments after homogenization, was added is as follows:

[0121] In Example 1 (Cu-4Ni-0.84Si-0.7Mn), the tensile strength during rolling and aging after homogenization treatment was significantly higher than that after casting and homogenization treatment, and was higher than that of Comparative Example 1 (Cu-4Ni-0.84Si), showing values ​​of 916 MPa, 952 MPa, 844 MPa, and 905 MPa.

[0122] In Example 2 (Cu-4Ni-0.84Si-1.42Mn), the tensile strength during rolling and aging after homogenization treatment was significantly higher than that after casting and homogenization treatment, and was higher than that of Comparative Example 1 (Cu-4Ni-0.84Si), showing values ​​of 987 MPa, 1103 MPa, 1041 MPa, and 1003 MPa.

[0123] In Example 5 (Cu-6Ni-1.26Si-2.14Mn), the tensile strength increased significantly after homogenization treatment, rolling, and aging treatment, resulting in higher strengths than Comparative Example 2 (Cu-6Ni-1.26Si), with values ​​of 923 MPa, 1009 MPa, 982 MPa, and 937 MPa.

[0124] As a result, we confirmed that by adding manganese (Mn) to a copper-nickel-silicon alloy in an appropriate amount, followed by homogenization, rolling, and aging, the strength of the alloy can be significantly increased, and it can possess excellent mechanical properties.

[0125] Table 5 below shows the electrical conductivity obtained from the processing heat treatment steps of Examples 1, 2, 5, and 6 and Comparative Examples 1, 2, and 4 of the present invention. [Table 5] Referring to Table 5, only in the case of Example 6 (Cu-2.8Ni-0.79Si-0.5Mn), Comparative Example 4 (Cu- 3.3 It exhibited electrical conductivity equivalent to or slightly higher than that of Ni-0.79Si.

[0126] As a result, it was confirmed that when manganese (Mn) is added to a copper-nickel-silicon alloy in an appropriate amount, the electrical conductivity does not decrease even after homogenization treatment, rolling, and aging treatment.

[0127] Figure 27 is a graph showing the manufacturing process of a copper-nickel-silicon alloy for friction coefficient measurement according to one embodiment of the present invention. Mn6Ni 16 To evaluate the wear resistance of copper-nickel-silicon alloys associated with the formation of the Si7 phase (G phase), copper-nickel-silicon alloys were manufactured by homogenization, rolling, and aging treatment. Test specimens were prepared by heating and melting the alloy components according to the composition shown in Table 2 above, and then homogenized and air-cooled at a temperature of 980°C for 8 hours. Subsequently, the alloys were cold-rolled to a reduction rate of 95% or less, aged at 400°C for 1 to 10 minutes, and air-cooled to produce copper-nickel-silicon alloys.

[0128] Figure 28 is a schematic diagram of a friction coefficient measurement test according to one embodiment of the present invention.

[0129] Figure 29 is a graph showing the results of a friction coefficient measurement test of a copper-nickel-silicon alloy according to one embodiment of the present invention.

[0130] Figure 30 is a graph showing the results of a wear test of a copper-nickel-silicon alloy according to one embodiment of the present invention.

[0131] Referring to Figures 28 and 29, the coefficient of friction in the example with manganese (Mn) added tends to be slightly lower than in the comparative example without manganese (Mn) added, and it can be confirmed that the coefficient of friction decreases even further when homogenization treatment is performed after casting.

[0132] Table 6 below shows the results of an abrasion test using one embodiment of the present invention.

[0133] [Table 6]

[0134] Referring to Figure 30 and Table 6, when manganese (Mn) was added to the copper-nickel-silicon alloy and homogenized, the wear test results showed the lowest wear amount of 0.0178g and the lowest friction coefficient of 0.480. As a result, it was confirmed that the wear resistance of the copper-nickel-silicon alloy of the present invention was improved when manganese (Mn) was added and homogenized.

[0135] As can be seen from the results above, the copper-nickel-silicon alloy of this invention is made by adding manganese (Mn) in an appropriate content ratio to nickel and silicon, and instead of Ni2Si precipitates formed at the grain boundaries of existing copper-nickel-silicon alloys, it is made of Mn6Ni 16 This induced the formation of the Si7 phase (G phase). Mn6Ni 16 As the Si7 phase is formed, a copper-nickel-silicon alloy with reduced inclusions can be developed, providing an alloy with improved mechanical properties, including strength and hardness, as well as improved workability and wear resistance. This alloy is expected to be suitable for application in automotive wear-resistant parts and the like. Furthermore, by using a homogenization-based aging process instead of the existing solution treatment-based aging process, the mechanical properties, workability, and wear resistance of the manganese (Mn)-added copper-nickel-silicon alloy can be effectively improved, and the reduced number of processes is expected to improve the economic efficiency of alloy manufacturing.

[0136] Having described in detail certain aspects of the present invention, it will be clear to those with ordinary skill in the art that such specific descriptions are merely preferred embodiments and do not limit the scope of the invention. Therefore, the substantial scope of the invention should be defined by the appended claims and their equivalents.

Claims

1. A copper-nickel-silicon (Cu-Ni-Si) alloy with manganese (Mn) added, With respect to the total weight of the aforementioned copper-nickel-silicon-manganese alloy, 2-6% by weight of nickel (Ni); 0.5 to 2% by weight of silicon (Si); 0.5 to 2.5% by weight of manganese (Mn); and It consists of copper (Cu) and the remainder of unavoidable impurities; Mn ６ Ni １６ Si ７ It is characterized by including a phase (G phase), The aforementioned Mn ６ Ni １６ Si ７ The compound is a copper-nickel-silicon-manganese alloy formed by a homogenization process.

2. With respect to the total weight of the aforementioned copper-nickel-silicon-manganese alloy, The copper-nickel-silicon-manganese alloy according to claim 1, comprising 0.7 to 2.2% by weight of manganese (Mn).

3. With respect to the total weight of the aforementioned copper-nickel-silicon-manganese alloy, The copper-nickel-silicon-manganese alloy according to claim 1, comprising 0.5 to 1.5% by weight of silicon (Si).

4. The copper-nickel-silicon-manganese alloy according to claim 1, wherein the content ratio of manganese (Mn) to nickel (Ni), Mn / Ni, is 0.175 to 0.

37.

5. The copper-nickel-silicon-manganese alloy according to claim 1, wherein the content ratio (Mn+Ni) / Si of the total manganese (Mn) and nickel (Ni) to silicon (Si) is 4.18 to 6.

46.

6. The copper-nickel-silicon-manganese alloy according to claim 1, wherein the content ratio of nickel (Ni) to silicon (Si) (Ni / Si) is 3.54 to 4.

76.

7. The copper-nickel-silicon-manganese alloy according to claim 1, wherein the copper-nickel-silicon-manganese alloy has a tensile strength of 830 to 1200 MPa.

8. i) The step of casting a copper-nickel-silicon-manganese alloy consisting of 2 to 6% by weight of nickel (Ni); 0.5 to 2% by weight of silicon (Si); 0.5 to 2.5% by weight of manganese (Mn); and the remainder of copper (Cu) and unavoidable impurities, relative to the total weight of the alloy; and ii) homogenizing the cast copper-nickel-silicon-manganese alloy, and Mn ６ Ni １６ Si ７ forming a compound; and a step of forming a Mn ６ Ni １６ Si ７ phase (G phase) at the grain boundaries of the produced copper-nickel-silicon-manganese alloy. A method for producing a copper-nickel-silicon-manganese alloy, characterized in that

9. The method for producing a copper-nickel-silicon-manganese alloy according to claim 8, wherein the homogenization treatment in step ii) is carried out at 900°C to 1100°C.

10. iii) The step of rolling the homogenized copper-nickel-silicon alloy; and iv) A method for producing a copper-nickel-silicon-manganese alloy according to claim 8, further comprising the step of aging the rolled copper-nickel-silicon alloy.

11. The method for producing a copper-nickel-silicon-manganese alloy according to claim 10, wherein the rolling in step iii) is performed by cold rolling of 85% to 95%.

12. The method for producing a copper-nickel-silicon-manganese alloy according to claim 10, wherein the aging treatment in step iv) is carried out at 350°C to 450°C for 1 to 15 minutes.

13. The method for producing a copper-nickel-silicon-manganese alloy according to claim 8, wherein the copper-nickel-silicon-manganese alloy produced has a manganese (Mn) to nickel (Ni) content ratio Mn / Ni of 0.175 to 0.

37.

14. The method for producing a copper-nickel-silicon-manganese alloy according to claim 8, wherein the copper-nickel-silicon-manganese alloy produced has a content ratio (Mn + Ni) / Si of 4.18 to 6.46 for the total manganese (Mn) and nickel (Ni) content of silicon (Si).

15. The method for producing a copper-nickel-silicon-manganese alloy according to claim 8, wherein the copper-nickel-silicon-manganese alloy produced has a nickel (Ni) to silicon (Si) content ratio Ni / Si of 3.54 to 4.76.

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