Cu-Fe-Mn-P alloy material and manufacturing method thereof

Abstract

The invention provides a Cu-Fe-Mn-P series alloy material, which contains 0.15 to 0.50 percent by weight of Fe, 0.15 to 0.50 percent by weight of Mn and 0.05 to 0.30 percent by weight of P, and further contains one or more of Ni, Mg, Cr, Sn, Zn, Zr, Ag, Ti and lanthanide series rare earth elements. The total amount of the Cu and the unavoidable impurities is 0.15 wt% or less, and the Cu and the unavoidable impurities meet the component proportional relation of the following formulas (1), (2) and (3): {Fe} + {Mn} + {P} is less than or equal to 1.0% (1); (2) 0.5 < = {Fe} / {Mn} < = 2.0; 2.0 < = ({Fe} + {Mn}) / {P} < = 5.0 (3); the Cu-Fe-Mn-P alloy material has good bending processability that the ratio R / t of the minimum bending radius to the plate thickness is smaller than 2.0, and the heat-resistant temperature is larger than or equal to 500 DEG C. The composite material can be used in the field of wide characteristic requirements of the electric conductivity of 60-90% IACS and the corresponding tensile strength of 800-600 MPa.

Description

Technical Field

[0001] The present invention relates to a Cu-Fe-Mn-P series alloy material and a manufacturing method thereof, which are used in various electrical and electronic components such as lead frames for integrated circuits, connectors, contact wires for high-speed railways, radiators, and relays, and have high requirements for material conductivity, heat transfer, and strength. Background Art

[0002] During the application of various electrical and electronic components, in order to effectively suppress excessive heat generation due to energization, the selected material needs to have excellent electrical conductivity and good heat conduction and heat dissipation characteristics. In addition, to ensure the stable transmission of current, sufficient contact pressure must be maintained between components, which puts higher requirements on the mechanical strength of the material. On the other hand, many electronic components usually obtain a specific shape through bending processing, so the material should also have excellent bending formability. Finally, to meet the long-term use requirements in high-temperature environments, the material also needs to have excellent heat resistance.

[0003] Currently, the medium-high conductivity and medium-high strength copper alloy materials widely used in the industry mainly focus on the following three alloy systems:

[0004] 1. Cu-Fe-P series alloy (such as C19400): Its conductivity is about 60-70% IACS, and its tensile strength is about 420-520 MPa;

[0005] 2. Cu-Ni-Si series alloy (such as C70250): Its conductivity is about 40-55% IACS, and its tensile strength is about 600-750 MPa;

[0006] 3. Cu-Cr-(Zr) series alloy (such as C18400, C18150, etc.): Its conductivity is about 75-85% IACS, and its tensile strength is about 480-560 MPa.

[0007] With the evolution of electrical and electronic components towards high-speed (high-current) transmission and miniaturization, as well as the rapid popularization of the electric vehicle and high-speed railway industries, the requirements for the conductivity and strength of copper alloy materials are increasing day by day. For example, at present, it is necessary to achieve at least a conductivity exceeding 60% IACS and a tensile strength exceeding 600 MPa. For more stringent applications, it is expected to reach a conductivity exceeding 65% IACS and a tensile strength above 650 MPa. However, the three known copper alloy systems at present cannot simultaneously meet these higher performance requirements, which to a certain extent hinders the further technological progress of the electrical and electronic industries.

[0008] The industry has conducted extensive research on the above alloy systems and added trace elements such as Sn, Zn, Mg, Ag, Ti, Co and rare earth elements to copper to develop dozens of improved alloys. However, the overall performance improvement of these improvements is still limited and it is difficult to meet the increasingly stringent application requirements. For example, the tensile strength of Cu-Fe-P alloys is generally difficult to exceed 550MPa; the tensile strength of Cu-Cr-(Zr) alloys is difficult to reach more than 600MPa; and although Cu-Ni-Si alloys can achieve higher strength, they cannot make the conductivity reach more than 60% IACS. These limitations have largely restricted technological progress in this field.

[0009] In recent years, Cu-Ni-P alloys have attracted attention from the industry because they can achieve a conductivity of about 60% IACS. For example, alloys such as C19000 (Cu-1.0% Ni-0.2% P) and UKC70 (Cu-0.8% Ni-0.13% P-0.1% Fe-0.1% Zn) developed by Kobe Steel, Japan, can achieve a conductivity of about 60-65% IACS and a tensile strength of 600-650 MPa through appropriate overaging treatment. However, this type of alloy adds a high content of Ni and P (more than 1.0wt%) to the copper matrix, which can improve the conductivity and strength, but significantly reduces the heat resistance and bending processability of the material, and it is still difficult to meet the actual use requirements.

[0010] In view of the actual needs of the market and the fact that existing copper alloys cannot simultaneously meet the requirements of high conductivity, high strength, good heat resistance and bending processability, the present invention has been developed and completed. Summary of the invention

[0011] The inventor of the present invention has conducted in-depth research on Cu-Fe-P and Cu-Mn-P alloys and found that when Cu-Fe-Mn-P alloys are under specific component combinations and specific processing and heat treatment conditions, the superposition effect of Fe-P precipitation strengthening and Mn-P precipitation strengthening can be achieved simultaneously, thereby obtaining a Cu-Fe-Mn-P alloy material with excellent comprehensive properties such as electrical conductivity, strength, heat resistance and bending processability. Based on this series of research findings, the present invention came into being.

[0012] Specific instructions:

[0013] The present invention provides a Cu-Fe-Mn-P alloy material, which contains 0.15-0.50wt% of Fe, 0.15-0.50wt% of Mn, 0.05-0.30wt% of P, and the remainder is Cu and inevitable impurities. The Cu-Fe-Mn-P alloy material has a composition ratio relationship satisfying the following formulas (1), (2) and (3):

[0014] {Fe}+{Mn}+{P}≤1.4% (1)

[0015] 0.5≤{Fe} / {Mn}≤2.0 (2)

[0016] 2.0≤({Fe}+{Mn}) / {P}≤5.0 (3)

[0017] Where {Fe}, {Mn} and {P} represent the weight percentages wt% of Fe, Mn and P in the Cu-Fe-Mn-P series alloy material respectively.

[0018] Preferably, the Cu-Fe-Mn-P series alloy material has a composition ratio relationship satisfying the following formulas (1), (2) and (3):

[0019] {Fe}+{Mn}+{P}≤1.0% (1)

[0020] 0.75≤{Fe} / {Mn}≤1.75 (2)

[0021] 2.5≤({Fe}+{Mn}) / {P}≤4.5 (3).

[0022] Preferably, it further contains one or more selected from Ni, Mg, Cr, Sn, Zn, Zr, Ag, Ti and rare earth elements of the lanthanide series, and the total amount is 0.15 wt% or less.

[0023] The conductivity of the above-mentioned Cu-Fe-Mn-P series alloy material is ≧60% IACS, and the tensile strength is ≧600 MPa.

[0024] Preferably, the Cu-Fe-Mn-P series alloy plate material has good bendability with a minimum bend radius to plate thickness ratio R / t less than 2.0, and the heat resistance temperature is ≧500 °C.

[0025] The conductivity is measured by the method specified in JIS-H0505. The tensile strength is measured by taking a specimen cut from the length direction of the material according to the method specified in JIS-Z2241. The bendability is for strip materials, and specimens (with a width of 10 mm) are taken in the length direction in the rolling direction (LD) and perpendicular to the rolling direction (TD), and bent by the 90° W-type bending process specified in JIS-H3110, and the ratio R / t of the minimum bend radius R without cracks to the plate thickness t is used for evaluation. The heat resistance temperature is the temperature corresponding to the Vickers hardness being 80% of the initial hardness before heat resistance under insulation for 30 min.

[0026] The present invention provides a method for manufacturing the Cu-Fe-Mn-P series alloy material, which includes sequentially performing the following steps on the Cu-Fe-Mn-P series alloy with the above composition: ingots cast by continuous or semi-continuous casting method, hot working such as hot rolling (hot forging, hot extrusion), cold working such as cold rolling (cold forging, cold drawing), heat treatment such as solution treatment and aging treatment, and conventional manufacturing processes such as surface milling and pickling. During the above manufacturing process, specific processing and heat treatment processes adopt the special process conditions of the present invention.

[0027] Specifically, it includes the following steps carried out in sequence:

[0028] S1: Ingots cast by continuous or semi-continuous casting method are hot worked by hot rolling, hot forging or hot extrusion;

[0029] S2: Cold working is carried out by cold rolling, cold forging or cold drawing;

[0030] S3: Solution treatment is carried out at a temperature between 800 - 1000 °C for 30 seconds to 2 minutes;

[0031] S3: Intermediate heat treatment is carried out at a temperature between 600 - 700 °C for 30 seconds to 3 minutes;

[0032] S4: Aging treatment is carried out at a temperature in the range of 300 - 500 °C for 3 - 10 hours;

[0033] S5: Low-temperature annealing is carried out after final cold rolling, cold forging or cold drawing.

[0034] Preferably, the temperature of the hot working in S1 is 920 - 1000 °C.

[0035] Preferably, in S3, intermediate heat treatment is carried out at a temperature between 650 - 720 °C for 0.5 to 1.5 minutes; in S4, aging treatment is carried out at a temperature in the range of 380 - 420 °C for 3 - 6 hours.

[0036] Preferably, the processing rate of the final cold rolling is 20 - 60%.

[0037] The Cu-Fe-Mn-P series alloy material obtained according to the present invention has excellent comprehensive properties that are difficult to obtain according to the current existing alloy compositions and manufacturing technologies. It is generated to meet the foreseeable future requirements for high current, high transmission, miniaturization and densification of electronic components.

[0038] I. Alloy Composition

[0039] Both Fe (iron) and Mn (manganese) can form compounds with P (phosphorus), and the precipitation strengthening of these compounds is utilized to enhance the strength of the copper alloy. When the Fe content is less than 0.15 wt%, the precipitation strengthening effect is insufficient; if the Fe exceeds 0.5 wt%, a too high solution temperature is required, making industrial production difficult. When the Mn content is less than 0.15 wt%, the precipitation strengthening effect is insufficient; if it exceeds 0.5 wt%, it is likely to cause an excessive decrease in the conductivity, and it is difficult for the final conductivity of the material to exceed 60% IACS. That is, the Fe content is between 0.15 - 0.5 wt%, and the Mn content is between 0.15 - 0.5 wt%. Preferably, the Fe content is between 0.20 - 0.40 wt%, and the Mn content is between 0.20 - 0.40 wt%.

[0040] The objective of the present invention is to fully consider achieving the conductivity and strength targets while taking into account heat resistance and bendability. Therefore, the total content of Fe, Mn, and P should not be too much and should satisfy the following formula (1):

[0041] {Fe} + {Mn} + {P} ≤ 1.0% (1);

[0042] Too many additive elements in the copper matrix are likely to exist in a solid solution form, resulting in a decrease in conductivity; even if the proportions of the elements satisfy the following ideal range, the precipitates are likely to form coarse particles, easily leading to a decrease in heat resistance, bendability, and corrosion resistance.

[0043] The objective of the present invention is to fully utilize the superposition effect of the precipitation strengthening of Fe - P and Mn - P compounds. Therefore, the contents of Fe and Mn should not differ too much and should satisfy the following formula (2)

[0044] 0.5 ≤ {Fe} / {Mn} ≤ 2.0 (2)

[0045] That is to say, the proportion of {Fe} or {Mn} in {Fe + Mn} is between 1 / 3 - 2 / 3. If the {Fe} / {Mn} ratio is less than 0.5 or greater than 2.0, the contents of Fe and Mn differ too much, and the alloy properties obtained are close to those of the Cu - Fe - P alloy system or the Cu - Mn - P alloy system, failing to achieve the objective of the present invention.

[0046] P (phosphorus) can form precipitates with both Fe and Mn to achieve the effect of precipitation strengthening. There are many types of precipitates, which vary with the content ratios of P, Fe, and Mn. The investigation results of the present invention show that when the content ratios of Fe, Mn, and P are within the range of the following formula (3), the best balance between conductivity and strength is obtained.

[0047] 2.5 ≤ ({Fe} + {Mn}) / {P} ≤ 5.0 (3)

[0048] This ratio reflects the balance of the respective contents of Fe and Mn in the P compound. A value less than 2.5 or greater than 5.0 indicates an excess or deficiency of the P content, both of which will lead to a decrease in conductivity and strength. It is preferred that the ratio of ({Fe}+{Mn}) / {P} is between 2.5 and 5.0. According to the Fe and Mn content ranges and formula (2), the P content is between 0.05 - 0.30 wt%. Additionally, if the P content is too high (such as above 0.3 wt%), hot working cracking problems are likely to occur. Therefore, within the range that satisfies formula (3), from the perspective of manufacturability, the upper limit of the ratio in formula (3) is preferably selected as much as possible, that is, a relatively low P content value. It is preferred that the P content is between 0.06 - 0.26 wt%.

[0049] For other elements, when necessary, one or more elements selected from Ni, Co, Mg, Cr, Sn, Zn, Zr, Ag, Ti, and lanthanide rare earth elements may be further contained according to specific circumstances. For example, Cr, Co, Mg, Zr, Ti, and lanthanide rare earth elements have the effects of refining grains and improving heat resistance; Sn and Ni have a solid solution strengthening effect; Zn has the effect of preventing the peeling off of the surface plating layer, and Ag has the effect of improving conductivity, etc. When one or more of these elements are added, to fully exert the above various effects, their total content is preferably 0.01 wt% or more. However, if the content of the above various elements is too high, it is likely to lead to a decrease in conductivity and damage the balance relationship between Fe - Mn - P, resulting in a deterioration of properties. Therefore, the total content of these elements is preferably controlled below 0.15 wt%, more preferably below 0.1 wt%, such as 0.075%.

[0050] II. Properties

[0051] 1. Electrical conductivity (and thermal conductivity) and strength

[0052] Currently, the high - conductivity and high - strength copper alloy strips most commonly used in components such as integrated circuit lead frames, smartphones, and computers (power terminals, USBs, chargers, etc.) can be mainly divided into three categories:

[0053] One category is: Cu - Fe(-P) alloys with an electrical conductivity of about 65% IACS (60 - 70% IACS), and the tensile strength is between 520 - 450 MPa; another category is: Cu - Ni - Si alloys with an electrical conductivity of about 45% IACS (40 - 50% IACS), and the tensile strength is between 600 - 750 MPa; the third category is: Cu - Cr(-Zr) alloys with an electrical conductivity of about 80% IACS (75 - 85% IACS), and the tensile strength is between 480 - 580 MPa.

[0054] With the miniaturization of electrical and electronic components and the increasing requirements for the strength of copper alloy materials, the strength of type I and type III copper alloys cannot meet the requirements. On the other hand, with the development requirements of high-current high-speed transmission and fast charging, the strength of type II copper alloys cannot meet the requirements. Therefore, the market demand for copper alloy materials with good characteristic balance, conductivity above 60% IACS, preferably above 60% IACS; tensile strength above 600 MPa, preferably tensile strength ≥ 650 MPa is getting higher and higher.

[0055] The temperature rise problem caused by high-current high-speed transmission is becoming more and more serious, and better heat dissipation (thermal conductivity) of copper alloy materials is required. Since the thermal conductivity coefficient is directly proportional to the conductivity, generally, the heat dissipation and conductivity are unified, that is, the quality of conductivity can be used to represent them uniformly.

[0056] 2. Heat resistance performance

[0057] Regarding the temperature rise problem caused by high-current high-speed transmission, on the one hand, it is to improve the alloy conductivity (heat dissipation), and at the same time, the heat resistance of the alloy is also required, that is, at a certain temperature, the strength (hardness) of the alloy material cannot be excessively low. Specifically, the heat resistance temperature is not lower than 500 °C.

[0058] 3. Bending processability

[0059] For high-conductivity copper alloy applications, generally, the bending processability is required to be relatively low. When the directions parallel and perpendicular to the rolling direction on the plate surface are called the LD and TD directions respectively, it is required that the bending processability in the LD and TD directions satisfies that the ratio R / t of the minimum bending radius R without cracking during 90° W-type bending and the plate thickness t is generally required to be below 2.0. The bending processability in the LD direction described here means that the specimen is cut with the length direction of the specimen parallel to the rolling direction, and the bending axis during bending is the TD direction. Similarly, the bending processability in the TD direction means that the specimen is cut with the length direction of the specimen perpendicular to the rolling direction, and the bending axis during bending is the LD direction.

[0060] The Cu-Ni-P series alloy developed in recent years has a conductivity between 60-65% IACS and a tensile strength between 650-600 MPa. However, its heat resistance and bending processability are difficult to meet the market requirements.

[0061] III. Manufacturing method

[0062] The copper alloy material of the present invention described above can be strip, rod, tube, and special-shaped materials, and can be manufactured, for example, through the following general process flow. That is: melting / casting - hot working (hot rolling, hot forging, hot extrusion, etc.) - cold working (cold rolling, cold forging, drawing, etc.) - heat treatment (solution treatment, aging, recrystallization annealing, etc.) - final finishing - low-temperature stress relief annealing, etc.

[0063] However, as described below, the control of several of these process conditions is very important. Additionally, although not mentioned above, depending on actual needs, optional surface milling can be performed after hot rolling, and optional pickling, grinding, or degreasing, stretch leveling, etc. can be performed after heat treatment. The following further describes each process using the strip material with the most complex manufacturing process as an example.

[0064] 1. [Melting and Casting]

[0065] Either continuous or semi - continuous casting methods for general copper alloys can be used. To prevent the oxidation of P, P should be added immediately before casting starts after Cu and other alloying elements are completely dissolved. Adding charcoal in the melting furnace and launder, or purging with nitrogen for protection can also be done.

[0066] 2. [Heating - Hot Working]

[0067] For the copper alloy of the present invention, the solid solution temperature of the coarse Fe - P and Mn - P compounds solidified between dendrites in the casting structure is relatively high. Therefore, the heating temperature should be slightly higher than that of general copper alloys, between 950 - 1000 °C. If the heating temperature is not high enough, the Fe - P and Mn - P compounds cannot be completely solid - solved (there will be residues), and there will be few fine precipitations during the final aging, resulting in low strength.

[0068] The ingot is heated at 950 - 1000 °C for 3 - 5 hours and then hot - worked (hot rolling, hot forging, hot extrusion, etc.). The hot - working process can be carried out according to the process of general copper alloys. It is best to water - cool as much as possible after hot - working to prevent the precipitation of Fe - P and Mn - P compounds.

[0069] 3. [Cold Working]

[0070] Next, cold working is carried out to the specified size according to the final product size and the final reduction ratio.

[0071] 4. [Solution Treatment]

[0072] In order to re - dissolve the small amount of Fe - P and Mn - P compounds precipitated during hot - working, solution treatment is carried out. The suitable solution treatment temperature varies with the alloy composition. Within the alloy composition range of the present invention, the suitable solution treatment temperature is between 800 - 1000 °C, and the treatment time can be between several seconds and several minutes. The appropriate solution treatment time varies with the treatment temperature and the material size and can be determined through experiments. Specifically, it can be determined by observing the structure after solution treatment. A precise method is to observe the presence or absence of precipitates through a transmission electron microscope, or a simple metallographic observation method can also be used, with a recrystallized grain diameter of about 10 μm as the condition for the basic solid solution of precipitates.

[0073] If the hot working temperature is relatively high, the cooling rate after hot working is fast, and the precipitates are few, the solution treatment this time can be omitted. Or when the conductivity requirement for the final product is relatively high and the strength requirement is relatively low, the solution treatment this time can also be omitted.

[0074] 5. [Cooling Control after Solution Treatment]

[0075] After conventional solution treatment, in order to prevent precipitation and coarsening of precipitates during the cooling process, rapid cooling (or water cooling), that is, so-called quenching, should be carried out after solution. Next, the general technological process is to carry out aging treatment (or cold working - aging treatment). For general precipitation-type copper alloys, there is an optimal precipitation temperature Tm (also the aging temperature) range. When aging at a temperature higher than Tm, the number of nuclei of precipitates is small and due to the high temperature, the precipitates grow fast, resulting in large-sized and low-density precipitates, and the precipitation strengthening effect is small; when aging at a temperature lower than Tm, both the nucleation and growth of precipitates are slow, and the precipitation strengthening effect is also small, or an extremely long aging time is required and large-scale production cannot be carried out.

[0076] The Cu-Fe-Mn-P series alloy has two types of precipitates, Fe-P and Mn-P, corresponding to different precipitation temperature ranges. The precipitation temperature range of Fe-P precipitates is approximately 600 - 800 °C, and the precipitation temperature range of Mn-P precipitates is 300 - 500 °C. If the Cu-Fe-Mn-P series alloy is aged at a relatively high temperature (such as 550 °C) for Fe-P precipitation, compared with Mn-P precipitates, the temperature is too high, the density of Mn-P precipitates is small and they grow rapidly, and the precipitation strengthening effect becomes very small; if it is aged at a relatively low temperature (such as 400 °C), compared with Fe-P precipitates, the temperature is too low, resulting in a small precipitation amount and a very small precipitation strengthening effect.

[0077] In the present invention, after solution treatment, contrary to the traditional rapid cooling treatment, slow cooling treatment is adopted. The purpose is to allow the material at a high temperature (such as 900 - 950 °C) after solution treatment to stay for several seconds to dozens of seconds during the cooling process to around 600 °C, intentionally allowing partial precipitation of Fe-P compounds, and since the time is very short, they will not coarsen. At the same time, in this temperature range, a small amount of precipitation of Mn-P compounds will promote the refinement of Fe-P precipitates. The cooling control after solution treatment can be achieved by using a conventional continuous annealing furnace (such as a cushion furnace and a vertical furnace with multiple heating - cooling zones), and controlling by adjusting the cooling conditions (such as air pressure and air flow) in the cooling zone and the sheet passing speed, etc. The specific residence time can be determined by the TTT curve obtained in advance in the laboratory for different compositions.

[0078] If the residence time between the solution temperature and 600 °C is too short, too little Fe-P compound will precipitate, and the precipitation strengthening effect of the present invention cannot be achieved. If the residence time is too long, it is easy to cause the rapid growth of Fe-P precipitates, and the effect of the present invention cannot be achieved either. Within the composition range of the present invention, the effect can be achieved between 10 and 60 seconds. If the production equipment does not have the ability to monitor the temperature and adjust the cooling conditions, it can also be achieved by means of intermediate heat treatment (i.e., after conventional solution quenching treatment, then solution quenching treatment at 600-700 °C). However, this only increases the process and manufacturing costs.

[0079] 6. [Aging treatment]

[0080] Next, aging treatment is carried out. The aging treatment temperature is preferably between 300 and 500 °C, and good results can be obtained when the aging treatment time is roughly in the range of 3 to 10 hours. The purpose of aging is to precipitate as much Mn-P compound as possible and further precipitate Fe-P compound. Through the superimposed precipitation effect of these two precipitates, the strength and conductivity of the material are improved. Similarly, if the aging temperature is too low and the aging time is too short, the precipitation is insufficient; if the aging temperature is too high and the aging time is too long, over-aging is likely to occur, resulting in low strength.

[0081] 7. [Final cold working]

[0082] In order to further improve the strength of the material, final cold working with a rolling rate of 20-60% can be carried out after aging treatment. As the processing rate increases, the strength increases, while the heat resistance and bendability decrease. Through detailed research and investigation, the inventor of the present invention found that if the rolling rate is controlled between 20-60%, the strength, heat resistance and bendability targets of the present invention can be achieved.

[0083] 8. [Low-temperature annealing]

[0084] If final cold working is carried out, in order to reduce and eliminate the residual stress in the material and improve the heat resistance, low-temperature annealing should be carried out after processing. At the same time, low-temperature annealing can also improve the conductivity. The heating temperature in low-temperature annealing can be set within 350-550 °C for continuous annealing for several seconds to several minutes, or within 150-350 °C for bell furnace annealing for several hours. Correspondingly, if the temperature is set too high, it is easy to cause softening of the sheet. On the contrary, if the temperature is set too low, the expected effect cannot be achieved. Examples

[0085] Square ingots with the compositions shown in Table 1 were cast using a vertical semi - continuous casting machine. After cutting off the head and tail of the ingots, they were heated to 960 °C and held for 3 hours, followed by hot rolling. After hot rolling, they were water - cooled, and the surface oxide film was removed by milling. Then, they were cold - rolled to the required thickness and then subjected to a solution treatment at 800 - 1000 °C. For alloys with different compositions, prior to that, metallographic observations were made through laboratory experiments at different solution treatment temperatures and times. The temperature and time corresponding to an average grain diameter of 8 - 15 μm after solution treatment were used as the temperature in the heating and soaking zones of the continuous annealing furnace, and the time obtained from the ratio of the furnace length in the heating and soaking zones to the sheet - passing speed.

[0086] Intermediate heat treatment at 600 - 700 °C for 1 min, aging treatment at 400 °C, and the aging time was adjusted at 400 °C to make the hardness reach the maximum value. The optimal aging treatment time for the alloy composition was obtained from prior experiments. After aging treatment, the material samples were finally cold - rolled at a rolling rate of 50%. After cold rolling, they were subjected to a low - temperature annealing for 1 min in a heating furnace at 400 °C. Pickling, degreasing, stretch - leveling, and trimming were carried out as necessary in the middle. Finally, the precipitates of the obtained sheets were observed and the properties were evaluated. The thickness of the specimens was uniformly 0.20 mm. The main manufacturing conditions of each specimen are shown in Table 2.

[0087]

Table 1

[0088]

[0089] Note: The lower line indicates that it exceeds the scope specified in the present invention.

[0090] The following evaluations were carried out on the properties of the obtained specimens. That is, conductivity, tensile strength, heat - resistant temperature, and bendability.

[0091] [Conductivity]: Measured according to the method specified in JIS - H0505.

[0092] [Tensile strength]: Measured according to the method specified in JIS - Z2241.

[0093] [Heat - resistant temperature]: Measured according to the method specified in GB / T33370 - 2016

[0094] [Bendability]: Plate - shaped specimens (with a width of 10 mm each) cut in the length directions of LD and TD were bent according to the 90°W - type bending method specified in JIS - H3110. The surface and cross - section of the specimens after bending were observed under an optical microscope at 100 times magnification. The minimum bending radius R without cracks was obtained. The ratio R / t of the minimum bending radius R to the sheet thickness t was used as the evaluation of bendability. The smaller the value of R / t, the better the bendability.

[0095] The results of the characteristic evaluation are shown in Table 2.

[0096]

Table 2

[0097]

[0098] Note: The underline indicates that it is beyond the specified scope of the present invention.

[0099] It can be seen from Table 2 that all the inventive examples have a good balance between conductivity and tensile strength under the composition requirements and manufacturing process conditions of the present invention, and the heat resistance temperature exceeds 500°C. At the same time, they have good bending processability with R / t in both LD and TD directions being less than 2.0.

[0100] In contrast, Comparative Examples No. 11-14 are examples where good properties are not obtained because the contents or ratios of Fe, Mn and P exceed the range specified in the present invention. The contents of Fe, Mn and P in No. 11 are too low, resulting in too few precipitates and low strength. Comparative Example No. 12 has an excessively high total content of added elements, with Fe+Mn+P reaching 1.329wt.%, which causes abnormal coarsening of the precipitate phase during the heat resistance test, resulting in a sharp drop in the heat resistance of the alloy. No. 13 and 14 are examples where the (Fe+Mn) / P ratio is too large and too small, that is, one side of (Fe+Mn) or P is relatively excessive, resulting in a small amount of precipitation, and relatively low strength and conductivity. No. 15 and 16 are examples where the Fe / Mn ratio is too large and too small, resulting in low strength or conductivity. The Fe content of No.15 is too low, resulting in a result similar to that of a general Cu-Mn-P alloy, that is, the tensile strength can reach a relatively high 730MPa, but the conductivity is only 52.6%IACS. On the contrary, the Mn content of No.16 is too low, resulting in a result similar to that of a general Cu-Fe-P alloy, that is, the conductivity is very high but the strength is too low. No.17 is an example of poor properties caused by excessive content of other elements. Since Co can also form compounds with P to precipitate, the excessive addition of Ni destroys the equilibrium relationship between Fe-Mn-P, resulting in lower conductivity and tensile strength than the invention example.

[0101] Comparative Examples No. 21 - 23 are examples of alloys of the alloy composition invention examples No. 1 - 3, where the manufacturing process conditions exceed the scope specified in the present invention and good properties are not obtained. In No. 21 - 23, intermediate heat treatment was not carried out, and the aging temperature and aging time were adjusted according to the normal process flow to achieve the optimal aging conditions. As a result, with other manufacturing conditions being the same as those in invention examples No. 1 - 3, both the strength and conductivity were far lower than those in invention examples No. 1 - 3. No. 24 and No. 25 are examples of alloys of the alloy composition invention example No. 2, where the inappropriate intermediate heat treatment conditions result in the failure to achieve the effects of the present invention. In No. 24, the intermediate heat treatment temperature was too low and the time was too short, resulting in too few Fe - P precipitates. The final conductivity and tensile strength were slightly higher than those of comparative example No. 22 without intermediate heat treatment, but far inferior to those of invention example No. 2. No. 25 is an example where the intermediate heat treatment time was too long or the temperature was too high, resulting in coarse Co - P precipitates, low strength, and a heat resistance lower than 500 °C.

Claims

1. A Cu-Fe-Mn-P alloy material, comprising 0.1-0.60wt% Fe, 0.1-0.60wt% Mn, 0.05-0.35wt% P, and the remainder being Cu and inevitable impurities, wherein the Cu-Fe-Mn-P alloy material has a composition ratio relationship satisfying the following formulas (1), (2) and (3): {Fe}+{Mn}+{P}≤1.4% (1) 0.5≤{Fe} / {Mn}≤2.0 (2) 2≤({Fe}+{Mn}) / {P}≤5.0 (3) Wherein {Fe}, {Mn} and {P} represent the weight percentage (wt%) of Fe, Mn and P in the Cu-Fe-Mn-P alloy material, respectively.

2. The Cu-Fe-Mn-P alloy material according to claim 1, characterized in that: It contains 0.15-0.50wt% Fe, 0.15-0.50wt% Mn, and 0.08-0.3wt% P. The Cu-Fe-Mn-P alloy material has a composition ratio relationship satisfying the following formulas (1), (2) and (3): {Fe}+{Mn}+{P}≤1.0% (1) 0.75≤{Fe} / {Mn}≤1.75 (2) 2.5≤({Fe}+{Mn}) / {P}≤4.5 (3).

3. The Cu-Fe-Mn-P alloy material according to claim 1 or 2, characterized in that: It also contains one or more selected from Ni, Mg, Cr, Sn, Zn, Zr, Ag, Ti and lanthanide rare earth elements, and the total amount is less than 0.15wt%.

4. The Cu-Fe-Mn-P alloy material according to claim 1 or 2, characterized in that: The electrical conductivity of the Cu-Fe-Mn-P alloy material is ≥60% IACS, and the tensile strength is ≥600 MPa.

5. The Cu-Fe-Mn-P alloy material according to claim 1 or 2, characterized in that: The Cu-Fe-Mn-P alloy plate material also has good bending workability with a minimum bending radius to plate thickness ratio R / t being less than 2.

0.

6. The Cu-Fe-Mn-P alloy material according to claim 1 or 2, characterized in that: The Cu-Fe-Mn-P alloy plate material also has a heat resistance temperature of ≥500°C.

7. The method for producing the Cu-Fe-Mn-P alloy material according to any one of claims 1 to 6, characterized in that: It includes the following steps performed in sequence: S1: Ingot cast by continuous or semi-continuous casting, hot processed by hot rolling, hot forging or hot extrusion; S2: Cold working by cold rolling, cold forging or cold drawing; S3: Solution treatment at 800-1000°C for 30 seconds to 2 minutes; S3: intermediate heat treatment at 600-700°C for 30 seconds to 3 minutes; S4: Aging treatment at a temperature range of 300-500°C for 3-10 hours; S5: Low temperature annealing after final cold rolling, cold forging or cold drawing.

8. The method for producing a Cu-Fe-Mn-P alloy material according to claim 7, characterized in that: The temperature of the hot working in S1 is 920-1000°C.

9. The method for producing a Cu-Fe-Mn-P alloy material according to claim 7, characterized in that: In the S3, an intermediate heat treatment is performed at 650-720° C. for 0.5 to 1.5 minutes; and in the S4, an aging treatment is performed at a temperature range of 380-420° C. for 3-6 hours.

10. The method for producing a Cu-Fe-Mn-P alloy material according to claim 7, characterized in that: The processing rate of the cold rolling is 20-60%.

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