Patent Application
20100170595
The present invention relates to a copper alloy material and to a method for production thereof.
A copper alloy material has been used for applications such as a lead frame, a connector, a terminal material, or the like of an electrical and electronic device, more specifically a connector or a terminal material to be mounted on a motor vehicle, a relay, a switch, a socket, or the like. In the applications, the copper alloy needs to have properties such as an electrical conductivity, an yield strength (an yield stress), a tensile strength, a bending workability and an yield stress relaxation characteristic. Recently, the properties need to be improved further as the demand for a smaller size, a lighter weight, a higher function, a higher package density, or a higher environment temperature of the electrical and electronic device increases.
Conventionally, a copper-based material such as phosphor bronze, red brass, brass, or the like, in addition to an iron-based material has been widely for an electrical and electronic device in general. A work hardening process is a combination of a solid solution hardening of Sn and/or Zn with a cold working such as a rolling out, a wire drawing, or the like, thereby improving strengths of the alloys. However, with the technique, it is difficult to obtain sufficient electrical conductivity. Moreover, the cold working is conducted at a higher processing rate to obtain a higher strength, so that it is difficult to obtain sufficient bending workability and yield stress relaxation characteristic.
To this end, a precipitation hardening is provided as a method for improving strength, in which a fine second phase in a nanometer order is precipitated in a material. With the method, it is possible to improve the strength and an electrical conductivity, thereby being available to various alloy systems. For example, in a Cu—Ni—Si based alloy (CDA70250 registered in CDA (Copper Development Association)), a chemical compound of Ni and Si is precipitated in Cu, thereby improving the strength. However, the Cu—Ni—Si based alloy does not have sufficient electrical conductivity, and it is necessary to improve the electrical conductivity.
In general, in a precipitation hardened type alloy, a solution heat treatment is introduced for solution heating a solute atom as an intermediate process before a heat aging precipitation treatment to obtain a fine precipitated state. The processing is conducted at a temperature between 750° C. and 1000° C. depending on an alloy system, a solute concentration, or the like. In order to obtain a sufficient amount of precipitation hardening, it is preferable to increase a concentration of the solute atoms, and to maintain a higher temperature in the process of treating to be solution heated to increase a density of the precipitation.
In order to obtain higher electrical conductivity, it is necessary to select a precipitation type copper alloy system having a small solid solubility limit of solute atoms into a copper matrix. In this case, a higher temperature is necessary to be solution heated in order to obtain a sufficient amount of precipitation hardening. When the temperature of the process of treating to be solution heated increases, a crystalline grain diameter of a material tends to increase. When the crystalline grain diameter becomes rough and large, a local transformation in the process of bending work tends to increase, thereby causing a crack or the like. Furthermore, a wrinkle tends to become large on a surface of a bend section, so that an electric current may be converged, or a plated surface of a material may crack when the bend section is used as a contact. Therefore, there is required a technology to decrease the crystalline grain diameter under a high temperature in the solution heat treatment.
An invention has disclosed a method for production of a copper alloy with high strength, in which a chemical compound of Ni and Ti is dispersed (refer to Japanese Patent Publication No. 04-053945). Moreover, another invention has disclosed a method for production of a copper alloy, in which a chemical compound of Ti and Fe is dispersed (refer to Japanese Patent Publication No. 07-258806).
However, it is difficult to improve the strength, the electrical conductivity, the yield stress relaxation characteristic, and the bending workability together, and it is not to completely meet the demand for all properties.
The present inventors have examined regarding a composition of a copper alloy material, an average crystalline grain diameter thereof, an electrical conductivity property, an yield strength, a stress relaxation characteristic and a bending workability. It is found that it becomes possible to improve the properties by controlling properly individual conditions, thereby achieving the present invention.
That is, the present invention provides the following aspects.
1. According to a first aspect of the present invention, a copper alloy material includes: an element X between 0.1% and 4% by mass, in which the element X represents one transition element or not less than two elements selected from Ni, Fe, Co and Cr; an element Y between 0.01% and 3% by mass, in which the element Y represents one element or not less than two elements selected from Ti, Si, Zr and Hf; and a remaining portion to be comprised of copper and an unavoidable impurity, wherein the copper alloy material has an electrical conductivity of not less than 50% IACS (international annealed copper standard), an yield strength of not less than 600 MPa, and a stress relaxation rate of not higher than 20% as to be measured after the same is maintained for 1000 hours at a state under applying a stress of 80% of the yield strength.
2. According to a second aspect of the present invention, the copper alloy material in the first aspect further includes an element Z between 0.01% and 3% by mass, in which the element Z represents one element or not less than two elements selected from Sn, Mg, Zn, Ag, Mn, B and P.
3. According to a third aspect of the present invention, in the copper alloy material in the first or the second aspect, an average crystalline grain diameter is not larger than 10 μm, and it is superior in bending workability.
4. According to a fourth aspect of the present invention, in the copper alloy material in one of the first to the third aspects, a second phase having a particle diameter between 50 nm and 1000 nm exists with a distribution density as not lower than 104 pieces per mm2.
5. According to a fifth aspect of the present invention, in the copper alloy material in the fourth aspect, the second phase is formed of a chemical compound which includes at least one element selected from Si, Co, Ni, Fe, Ti, Zr and Cr.
6. According to a sixth aspect of the present invention, in the copper alloy material in the fourth or the fifth aspect, the second phase is formed of a chemical compound which is comprised of three elements.
7. According to a seventh aspect of the present invention, a method for production of the copper alloy material in one of the first to the sixth aspects, comprises the steps of: casting (1); treating with heat for homogenizing (2); hot working (3); facing (4); cold working (6); treating with heat to be solution heated (7); cold working (9); treating with heat for aging precipitation (10); cold working (11); and annealing to be heat treated for refining (12). The processes are performed in order on a copper alloy raw material, and a sum of a processing rate as an R1(%) at the step of cold working (9) and a processing rate as an R2(%) at the step of cold working (11) is between 5% and 65%.
8. According to an eighth aspect of the present invention, a method for production of the copper alloy material for an electronic/electrical device in one of the first to the sixth aspects, comprises the steps of: casting (1); treating with heat for homogenizing (2); hot working (3); facing (4); cold working (6); treating with heat to be solution heated (7); treating with heat for aging precipitation (8); cold working (9); treating with heat for aging precipitation (10); cold working (11); and annealing to be heat treated for refining (12), wherein the processes are performed in order onto a substance for the copper alloy material, a sum of a processing rate as an R1(%) at the step of cold working (9) and a processing rate as an R2(%) at the step of cold working (11) is between 5% and 65%, a heat treatment temperature at the step of treating with heat for aging precipitation (8) is between 400° C. and 700° C., and a heat treatment temperature at the step of treating with heat for aging precipitation (10) is as lower than the heat treatment temperature at the step of treating with heat for aging precipitation (8).
9. According to a ninth aspect of the present invention, in the method for production of the copper alloy material for an electronic/electrical device in the seventh or the eighth aspect, a further step of treating with heat for aging precipitation (5) is performed with a temperature between 400° C. and 800° C. for between five seconds and twenty hours after the step of facing (4), and the step of cold working (6) is performed thereafter.
The above and other aspects and advantages according to the present invention will be further clarified by the following description, with reference to the drawings.
An embodiment to be preferred for a copper alloy material according to the present invention will be described in detail below.
First of all, reasons for adding each component and content constituting a copper alloy material of the present invention applicable to an electrical machinery and apparatus and to electronic equipment will be explained.
According to the present invention, an element X represents a transition element that has a 3d electron in an outer shell, such as Ni, Fe, Co, Cr, or the like. Moreover, an element Y represents an element that has valence electrons as two pieces or four pieces, such as Ti, Si, Zr, Hf, or the like. Moreover, the elements X and the elements Y may be a chemical compound, such as NiSiTi, NiSiZr, CoSiTi, Co2Si, CuSiTi, CoHfSi, CuHfSi, Fe5Si3, Ti5Si3, Ni3Ti2Si, Co3Ti2Si, Cr3Ti2Si, Fe2Ti, Ni3Zr2Si, CoSiZr, Cr2Ti, CrMnTi, Ni2Si, Ni3Si, Ni9Ti2Zr, or the like. Further, the chemical compounds or a chemical compound in which any of the constituent elements are substituted by another element are precipitated mostly with a fine size as not larger than 50 nm as a matrix in the copper. The elements X and the elements Y have a function to improve the strength, the electrical conductivity and the yield stress relaxation characteristic.
Still further, it is not desirable regarding the effect in a case where each of the contents for the elements X is not larger than 0.1 mass %, or where each of the contents for the elements Y is not larger than 0.01 mass %, because the amount of precipitation hardening is not sufficient. Still further, it is not desirable either in a case where any one of the elements X is not less than 4 mass %, or where any one of the elements Y is not less than 3 mass %, because there is generated a crystallized precipitate as rougher and larger in a texture of the alloy material, that may worsen a plating ability thereon, may become a cause to generate a crack at the period of bending work, or the like.
Therefore, a range for any one of the element X should be between 0.1 mass % and 4 mass %, and it is desirable to be between 0.3 mass % and 3.0 mass %, or it is further preferable to be between 0.3 mass % and 2.5 mass %. Furthermore, a range for any one of the element Y to be contained should be between 0.01 mass % and 3 mass %, and it is desirable to be between 0.03 mass % and 2.0 mass %, or it is further preferable to be between 0.04 mass % and 1.5 mass %.
According to the present invention, an element Z represents Sn, Mg, Zn, Ag, Mn, B and P.
The elements of the Sn, the Mg, the Zn, the Ag and the Mn have a function that improves the strength, the yield stress relaxation characteristic, or the like, due to a synergistic effect as to be formed a chemical compound with any of the elements X and/or any of the elements Y, or by being solution heated in a copper alone. Moreover, due to the B and the P it becomes able to obtain the function that improves the strength thereof and the yield stress relaxation characteristic thereof, by increasing a density of a fine precipitate that is comprised of any of the elements X and any of the elements Y, or any of the elements X, any of the elements Y and any of the elements Z. Further, any of the elements Z may become the constituent elements for a second phase that will be described below and that has an advantage in order to control a crystalline grain diameter thereof.
Still further, there may be a case where it is not able to obtain sufficiently the functions and the advantages in a case where the content of any one of the elements Z is excessively low. Furthermore, there may be given rise to such as a decrease in the electrical conductivity thereof, a worsening of castability, or the like, in a case where the content thereof is excessively high. Therefore, a range of the content of any one of the elements Z is normally between 0.01 mass % and 3 mass %, and it is desirable to be between 0.03 mass % and 2 mass %, or it is further preferable to be between 0.05 mass % and 1.0 mass %.
Here the copper alloy material according to the present invention has the electrical conductivity of not less than 50% IACS, the yield strength of not less than 600 MPa, and the stress relaxation rate of not higher than 20% as to be measured after the same is maintained for 1000 hours at a state under applying a stress of 80% of the yield strength thereof. Moreover, there any upper limit is not set for the electrical conductivity thereof, however, the same is normally not more than 70% IACS. Further, any upper limit either is not set for the yield strength, however, the same is normally not more than 900 MPa. Still further, the above mentioned stress relaxation rate thereof is normally as not lower than 8%, though there is not set any lower limit either.
Still further, it is able to measure the stress relaxation rate thereof under a condition at approximately 150° C. for 1000 hours with loading an 80% of the yield strength thereof as an initial stress by making use of a cantilever method, that is pursuant to the standard specification EMAS-3003 of Electronic Material Association of Japan, and that will be described in further detail later.
Still further, it is able to control the crystalline grain diameter thereof by performing a solution heat treatment at a higher temperature. And then it is able to obtain the bending workability as to be more excellently in a case where an average of the crystalline grain diameter thereof is not larger than 10 μm. Still further, it becomes able to obtain further function and advantage that improve the strength thereof by designing the crystalline grains to be as smaller. That is to say, it becomes able to obtain the excellent bending workability and the excellent strength thereof by designing the preferable average crystalline grain diameter thereof as not larger than 6 μm, or by designing the same as not larger than 4 μm as further preferably. Still further, there is no lower limit in particular regarding the average crystalline grain diameter thereof, however, the same is not smaller than 3 μm in a normal case.
Still further, it is able to measure the average crystalline grain diameter thereof according to the JISH0501 as a method of section that will be described in detail later.
Still further, it is found out according to the present invention that it is effective to diffuse a second phase that has the particle diameter between 50 nm and 1000 nm with a density thereof as not lower than 104 pieces per mm2 regarding the control of the crystalline grain diameter thereof. Here, the second phase principally means a precipitate and a part of crystallized precipitates. And then it becomes able to obtain an advantage that suppress a growth of recrystallized grains in a case where the second phase exists at the solution heat treatment at a higher temperature of such as not lower than 750° C. approximately. As a result, it becomes able to further improve the strength thereof as further higher and the bending workability thereof as well, because it becomes able to maintain the crystalline grain diameter as further smaller. Here, it is desirable to design the particle diameter of the second phase to be between 60 nm and 800 nm, or it is further preferable to be between 70 nm and 700 nm. Still further, it is desirable to design the distribution density thereof as not lower than 105 pieces per mm2.
Further, the effect to suppress the growth of the grains becomes to be decreased in a case where the particle diameter of the above mentioned second phase is excessively smaller. On the contrary in a case where the same thereof is excessively larger, there may be given rise to such as a worsening in bending workability thereof, a decrease in density of the second phase thereof, or the like.
Furthermore, it is able to measure the particle diameter of the second phase and the distribution density thereof according to a method that will be described in detail later.
Here according to the second phase, it becomes able to enhance the functions and the advantages that suppress the crystalline grain diameter thereof as not to be rougher and larger, because the second phase becomes able to exist stably without being solution heated in the copper even at a higher temperature thereof by being composed of the element that has a melting point not lower than 1400° C., such as Si, Co, Ni, Fe, Ti, Zr, Cr, or the like.
Moreover, the following cases are included to be more specific regarding a configuration of the second phase:
A. a case where any one of the above mentioned elements is a single element;
B. a case where any one of the above mentioned elements is a chemical compound which contains Si, Co, Ni, Fe, Ti, Zr and Cr; and
C. a case where any one of the above mentioned elements forms a chemical compound which is bound with copper, such as Cu—Zr, Cu—Hf, or the like.
Further, as a case of the (B) for example, there may be given an example that is formed a chemical compound, such as Ni—Co—Cr—Si, Co—Si, Ni—Co—Si, Cr—Ni—Si, Co—Cr—Si, Ni—Zr, Mn—Zr, Ni—Mn—Zr, Fe—Zr, Mn—Zr, Fe—Mn—Zr, Ni—Ti, Co—Ti, Ni—Co—Ti, Fe—Ni—Si, Fe—Si, Mn—Si, Ni—Mn—P, Fe—P, Ni—P, Fe—Ni—P, Mn—B, Fe—B, Mn—Fe—B, Ni—B, Cr—B, Ni—Cr—B, Ni—Co—B, Ni—Co—Hf—Si, Ni—Co—Al, Ni—Ca, Ni—Co—Mn—Sn, Co—Ni—P, Al—Hf, Al—Zr, Al—Cr, or the like.
Furthermore, it is more preferable for the second phase to be as a chemical compound that is comprised of three elements as ternary, such as Cr—Ni—Si, Co—Cr—Si, Fe—Ni—Si, or the like.
Next, a preferred process of treatments will be exemplarily described in detail below regarding a method for production of a copper alloy material, that draw out as most effectively the aspects of the alloy systems according to the present invention, and that is suitable for an application to an electrical and electronic device.
The following processes are performed in order onto a substance for a copper alloy material, that comprises the steps of: casting (1); treating with heat for homogenizing (2); hot working (3); facing (4); cold working (6); treating with heat to be solution heated (7); cold working (9); treating with heat for aging precipitation (10); cold working (11); and then annealing to be heat treated for refining (12).
Here the step of cold working (6) has a function thereby a precipitated state of the fine precipitate becomes to be higher in density thereof and finer by controlling thereof at the step of treating with heat to be solution heated (7). And then thereby it becomes able to improve the strength thereof, the electrical conductivity thereof, and the yield stress relaxation characteristic thereof. Moreover, it becomes able to improve the strength thereof due to the work hardening by making use of the step of cold working (9). Further, it is desirable for a sum of a processing rate as an R1(%) at the step of cold working (9) and a processing rate as an R2(%) at the step of cold working (11) to be between 5% and 65%.
Still further, there may be a case where the above mentioned advantage is not sufficiently obtained in a case where the sum of the processing rates of the both steps of cold working is excessively smaller. Still further, there may be a case where the bending workability becomes to be worsened excessively in a case where the sum thereof is excessively larger. Therefore, it is able to design all of the properties thereof as excellently by controlling the sum of the processing rates of the two steps thereof to be between 5% and 65%. Furthermore, the processing rates is desirable to be between 10% and 60%, or it is further preferable to be between 15% and 55%.
In addition to the above mentioned processes regarding the method for production of the copper alloy material according to the present invention, it is desirable to add a heat aging precipitation treatment (8) after the solution heat treatment (7) in the above mentioned processes of treatments. Here, the heat aging precipitation treatment (8) has a function that the precipitated state becomes further higher in density thereof and further finer in the heat aging precipitation treatment (8), because it gives a core for the precipitation, with increasing a dislocation density thereof at the process of cold working (7). And then thereby it becomes able to improve the strength thereof, the electrical conductivity thereof and the yield stress relaxation characteristic thereof. Moreover, a temperature of the heat aging precipitation treatment (8) should be within a temperature range between 400° C. and 700° C., and it is desirable to be between 425° C. and 675° C., or it is further preferable to be between 450° C. and 650° C. On the contrary, there may be a case where the above mentioned advantage is not sufficiently obtained, because a precipitated amount is too lower in a case where the temperature thereof is excessively lower, or because a precipitate becomes rougher and larger in a case where the same is excessively higher. Therefore, it is able to obtain the most excellent properties thereof in a case between 400° C. and 700° C. with an amount of time for between five seconds and twenty hours.
Further, it is desirable to design a processing temperature for the heat aging precipitation treatment (10) to be as lower than the processing temperature for the of treating with heat for aging precipitation (8), because it is necessary to maintain the precipitate to be as higher in density thereof and finer that contributes to the precipitation hardening thereof.
Still further, it is desirable to perform the heat aging precipitation treatment (5) with a processing temperature between 400° C. and 800° C. for between five seconds and twenty hours after the process of facing (4), that is a method in order to control a dispersion state of the second phase which has a particle diameter between 50 nm and 1000 nm. Here the second phase is precipitated, such as at the cooling process in the process of hot working (3), at the process of raising the temperature thereof in the solution heat treatment (7), that is designed in order to control the crystalline grain diameter thereof, and that contributes to control the crystalline grain diameter thereof as smaller. Moreover, the heat aging precipitation treatment (5) has a function thereby the density of the above mentioned second phase becomes further higher. On the contrary the advantage becomes to be decreased in a case where the temperature thereof is excessively lower, or in a case where the same is excessively higher, or in a case where an amount of time for the process is excessively shorter. Further, the advantage becomes to be decreased either in a case where the amount of time for the process is excessively longer, because the distribution density of the second phase becomes rougher and larger. Hence it is desirable for the temperature range of the heat aging precipitation treatment (5) to be between 425° C. and 675° C., or it is further preferable to be between 450° C. and 650° C.
Thus, it becomes able to provide the copper alloy material and the method for production thereof according to the present invention, that is superior in the electrical conductivity thereof, the strength thereof, the yield stress relaxation characteristic thereof and the bending workability thereof at the same time, and that is the most suitable for the application to an electrical and electronic device. In an assessment of the stress relaxation characteristic thereof, it is able to obtain the advantages at least under a state of not higher than 150° C. for the copper alloy material according to the present invention, though the assessment is performed at the temperature of 150° C. as pursuant to the standard specification.
Moreover, it becomes able to provide the copper alloy material according to the present invention, that is superior in the electrical conductivity thereof, the strength thereof, the yield stress relaxation characteristic thereof and the bending workability thereof, and that is suitable for the application to such as a connector for an electrical and electronic device, a material for a terminal, or the like, and more specifically to such as a connector or a material for a terminal to be made use for such as mounting on a motor vehicle, a relay, a switch, a socket, or the like. Furthermore, it becomes able to provide a copper alloy material of precipitation type and a technology in order to control a crystalline grain diameter thereof at a period of production in particular, that it is difficult to realize the higher electrical conductivity as not lower than 50% IACS with making use of Cu—Ni—Si system on the contrary.
Next, the present invention will be described in further detail below, with reference to the following examples, however, the present invention will not be limited to any one of the examples.
Here there is performed an examination on the characteristics thereof as described below regarding each of copper alloy materials as sample materials that are obtained according to the following examples.
A. Yield Strength (YS):
There is performed a measurement for three test pieces for the number as JIS Z2201-12B with being pursuant to JIS 22241, that are cut out in a direction as parallel to a rolling. And then there is calculated an average value thereof.
B. Electrical Conductivity (EC):
There is performed a measurement of specific resistance by making use of the four terminal method in a constant temperature bath which is maintained at 20° C. (±0.5° C.), and then thereby there is calculated the electrical conductivity thereof. In the case thereof there is assumed to be as 100 mm regarding a distance between each of the terminals.
C. Stress Relaxation Rate (SR):
There is performed a measurement thereof under the condition at approximately 150° C. for 1000 hours, that is pursuant to the standard specification EMAS-3003 of Electronic Material Association of Japan. Moreover, there is loaded an 80% of the yield strength thereof as the initial stress by making use of the cantilever method.
And then there is performed a calculation of the stress relaxation rate (%) thereof in accordance with the following formula, according to the above mentioned relations.
(Ht−H1)/(δ0−H1)×100
In the formula, δ0 designates the distance from the reference level regarding the test piece at the period when the same is bended, the H1 designates the distance from the reference level regarding the test piece at the time when the same is not bended, and the Ht designates the distance from the reference level regarding the test piece that is after being performed the process of treating with heat and being bended, and then that is after unloading.
D. Bending Workability (R/t):
Each test piece is cut out with a width of 10 mm and a length of 25 mm in a direction as parallel to the rolling direction thereof. And then there is performed a W-bending with an axis of bending each thereof in parallel to the rolling direction thereof or in a right angle. Moreover, there is performed thereafter an observation whether or not any cracking at each part of the bending work thereof by making use of an optical microscope and a scanning electron microscope (SEM). And then thereby there is adopted a ratio between a bend radius as an R and a board thickness as at that are the limit values of which there is not occurred any cracking thereon. And hence there is performed a calculation of the ratio as R/t. Further, the samples are selected from the sample materials for the above mentioned measurements, that have individual board widths w of approximately ten millimeters, and then on which surfaces are rubbed slightly with making use of a metal polishing powder in order to remove an oxide film layer thereon. And then thereafter there is performed the above mentioned w-bending for each thereof to have individual angles at each inner side of the bending thereof as ninety degrees respectively, for the samples with the w-bending in parallel to the rolling direction (Good Way: GW hereinafter), and for the other samples with the w-bending in a right angle to the rolling direction (Bad Way: BW hereinafter). And hence there is performed the above mentioned measurements for the two types of the samples.
E. Average Crystalline Grain Diameter (Grain Size: GS):
At first there is performed a finishing for some sample materials to have individual mirror finished surfaces for individual cut faces thereon that are in a right angle to the rolling direction, by making use of a wet polishing and then by making use of a buffing. And then thereafter there is performed a corrosion on the polished surfaces thereof for a several seconds with making use of a solution of chromic acid:aqua=1:1. Moreover, there is performed taking some photographs by making use of the scanning electron microscope (SEM) with a reflection electron image at a magnifying power between 400 times and 1000 times. And hence there is performed a measurement for a particle diameter on individual cut faces thereof by making use of a crosscut method as pursuant to JIS H0501.
F. Particle Diameter and Distribution Density of Second Phase:
At first there is performed a punching out for some sample materials to have individual diameters of approximately three millimeters. And then thereafter there is performed a thin film polishing by making use of a twin jet polishing method to produce a test piece for observation. Moreover, photographs are taken as ten fields of view for each thereof by a transmission electron microscope (TEM) with a magnification of 2000 times and 40000 times and an acceleration voltage of 300 kV. A particle diameter of the second phase and the distribution density thereof are measured. The number of the particles having individual diameters between 50 nm and 1000 nm in each field of view is measured, and then there is performed an arithmetic execution on the number of pieces to be converted into a part per a unit area (per mm2). Furthermore, the chemical compounds are identified by making an energy dispersive X-ray spectroscopy (EDX) attached to TEM.
At first there is performed a mixing of the elements X and of the elements Y in order to obtain the content and the composition (mass %) as shown in the following Table 1-1 and Table 1-2. Moreover, there is performed thereafter a dissolution of an alloy by making use of a high frequency melting furnace, in which a remaining portion is comprised of copper and an unavoidable impurity. And hence there is obtained an ingot by casting the same with a cooling rate between 0.1° C. per second and 100° C. per second. Further, there is performed a process of treating with heat for homogenizing the same at between 900° C. and 1050° C. for between a half hour and ten hours. And then thereafter there is performed a process of hot working for the same with a reduction in area of not less than 50% at a processing temperature of not lower than 650° C. A water quenching is performed thereafter, and a facing is performed in order to remove an oxidizing scale.
Thereafter, the copper alloy materials is produced through one of the Processes A to D described below and indicated with the capital letters.
Process A: there is performed a process of cold working with a reduction in area between 50% and 98%, there is performed a solution heat treatment at a temperature between 800° C. and 1000° C., there is performed another process of cold working with a reduction in area between 5% and 50%, there is performed a heat aging precipitation treatment at a temperature between 400° C. and 650° C., there is performed a process of finishing cold working with a reduction in area between 5% and 50%, and then there is performed a process of annealing to be heat treated for refining at a temperature between 200° C. and 450° C. with an amount of time for between five seconds and ten hours.
Process B: there is performed the process of cold working with the reduction in area between 50% and 98%, there is performed the solution heat treatment at the temperature between 800° C. and 1000° C., there is performed a heat aging precipitation treatment at a temperature between 400° C. and 650° C., there is performed the other process of cold working with the reduction in area between 5% and 50%, there is performed another heat aging precipitation treatment at the temperature between 400° C. and 650° C., there is performed the process of finishing cold working with the reduction in area between 5% and 50%, and then there is performed a process of annealing to be heat treated for refining at a temperature between 200° C. and 550° C. with the amount of time for between five seconds and ten hours.
Process C: there is performed the heat aging precipitation treatment at the temperature between 400° C. and 650° C., there is performed the process of cold working with the reduction in area between 5% and 98%, there is performed the solution heat treatment at the temperature between 800° C. and 1000° C., there is performed the other process of cold working with the reduction in area between 5% and 50%, there is performed the other heat aging precipitation treatment at the temperature between 400° C. and 650° C., there is performed the process of finishing cold working with the reduction in area between 5% and 50%, and then there is performed the process of annealing to be heat treated for refining at the temperature between 200° C. and 550° C. with the amount of time for between five seconds and ten hours.
Process D: there is performed the heat aging precipitation treatment at the temperature between 400° C. and 650° C., there is performed the process of cold working with the reduction in area between 5% and 98%, there is performed the solution heat treatment at the temperature between 800° C. and 1000° C., there is performed another heat aging precipitation treatment at a temperature between 400° C. and 550° C., there is performed the process of cold working with the reduction in area between 5% and 50%, there is performed the other heat aging precipitation treatment at the temperature between 400° C. and 650° C., there is performed the process of finishing cold working with the reduction in area between 5% and 50%, and then there is performed the process of annealing to be heat treated for refining at the temperature between 200° C. and 550° C. with the amount of time for between five seconds and ten hours.
Moreover, a part of each of the obtained copper alloy materials is treated as individual sample materials. Further, there are performed the examination on the characteristics of the yield strength (YS), the electrical conductivity (EC) and the stress relaxation rate (SR). Furthermore, there are shown the obtained results in Table 1-1 and Table 1-2.
As it is obvious according to Table 1-1, the present invention samples 1-1 through 1-32 are superior in the yield strength thereof, the electrical conductivity thereof and the yield stress relaxation characteristic thereof. However, in the case of the samples that do not satisfy the conditions according to the present invention as shown in Table 1-2 on the contrary, it is not able to obtain any aspects that is superior. That is to say, the comparative sample 1-1 has the density of the precipitate as lower because of the amount of the element X as lower, and then thereby the same has the strength, the electrical conductivity and the yield stress relaxation characteristic as inferior. Moreover, the comparative sample 1-2 has the electrical conductivity as inferior, because there becomes to be increased the amount of the atoms thereof to be solution heated due to the amount of the element X as larger. Further, the comparative sample 1-3 has the density of the precipitate as lower because of the amount of the element Y as lower, and then thereby the same has the strength, the electrical conductivity and the yield stress relaxation characteristic as inferior. Furthermore, the comparative sample 1-4 has the electrical conductivity as inferior, because there becomes to be increased the amount of the atoms thereof to be solution heated due to the amount of the element Y as larger.
At first there is performed a mixing of the elements X, the elements Y and of the elements Z in order to obtain the content and the composition as shown in the following Table 2-1 and Table 2-2, in which a remaining portion is comprised of copper and an unavoidable impurity. And then thereafter there is performed a production of the copper alloy in accordance with the method for production as similar to that as described in the above mentioned Example 1. Moreover, a part of each of the obtained copper alloy materials thereby is treated as individual sample materials. Further, there are performed the examination on the characteristics thereof as similar to that according to the Example 1. The results are shown in Table 2-1 and Table 2-2.
As it is obvious according to Table 2-1, the present invention samples 2-1 through 2-32 are superior in the yield strength thereof, the electrical conductivity thereof and the yield stress relaxation characteristic thereof. However, in the case of the samples that do not satisfy the specified values regarding the conditions for each of the ingredient amounts according to the present invention as shown in Table 2-2 on the contrary, it is not able to obtain superior aspects. That is to say, the comparative samples 2-1 to 2-3 individually have the electrical conductivities as too inferior, due to the individual amounts of the elements Z in each thereof as excessively larger.
At first there is performed a mixing of the elements X, the elements Y and of the elements Z in order to obtain the content and the composition as shown in the following Table 3-1 and Table 3-2, in which a remaining portion is comprised of copper and an unavoidable impurity. And then thereafter there is performed a production of the copper alloy in accordance with the method for production as similar to that as described in the above mentioned Example 1. Moreover, a part of each of the obtained copper alloy materials thereby is treated as individual sample materials. Further, there are performed the solution heat treatment for the comparative samples 3-1 to 3-3 at a temperature thereof as approximately between 20° C. and 30° C. higher than that for each of the process of production according to the individual present invention samples 3-1 to 3-3 respectively.
Still further, there are performed the examination on the characteristics of the average crystalline grain diameter (GS) and the bending workability (R/t) thereof regarding each of the sample materials, in addition to that of the yield strength (YS), the electrical conductivity (EC) and the stress relaxation rate (SR) thereof as similar to that according to Example 1. Furthermore, there are shown the obtained results in Table 3-1 and Table 3-2.
indicates data missing or illegible when filed
As it is obvious according to Table 3-1, the present invention samples 3-1 through 3-32 are superior in the yield strength thereof, the electrical conductivity thereof and the yield stress relaxation characteristic thereof. However, in the case of the comparative samples 3-1 to 3-3 as shown in Table 3-2 that individually have the temperatures regarding the solution heat treatment as higher respectively, the sample materials individually have the crystalline grain diameters as larger than 10 μm respectively, and then that are inferior in the bending workability.
At first there is performed a mixing of the elements X, the elements Y and of the elements Z in order to obtain the content and the composition as shown in the following Table 4-1 and Table 4-2, in which a remaining portion is comprised of copper and an unavoidable impurity. And then thereafter there is performed a production of the copper alloy in accordance with the method for production as similar to that as described in the above mentioned Example 1. Moreover, a part of each of the obtained copper alloy materials thereby is treated as individual sample materials. Further, there are performed the solution heat treatment for the comparative samples 4-1 to 4-3 approximately at a temperature of 1200° C. for ten minutes respectively.
Still further, there are performed the examination on the characteristics of the constituent elements and the particle density thereof that individually have the particle diameters between 50 nm and 1000 nm and that comprise the second phase regarding each of the sample materials, in addition to that of the yield strength (YS), the electrical conductivity (EC), the stress relaxation rate (SR), the average crystalline grain diameter (GS) and the bending workability (R/t) thereof as similar to that according to Example 3. Still further, there are shown the obtained results in Table 4-1 and Table 4-2. Furthermore, the symbol 10̂n designates 10n in the tables (as similar in the tables hereafter).
As obvious in Table 4-1, the present invention samples 4-1 through 4-32 are superior in the yield strength thereof, the electrical conductivity thereof, the yield stress relaxation characteristic thereof and the bending workability thereof. However, in the case of the comparative samples 4-1 to 4-3 as shown in Table 4-2 that individually have the particle densities of the second phases as lower respectively, the sample materials individually have the crystalline grain diameters as larger than 10 μm respectively, and then thereby that are inferior in the bending workability on the contrary.
At first, the elements are mixed to obtain the content and the composition as shown in Table 5-1. Moreover, there is performed a dissolution thereafter for an alloy by making use of the high frequency melting furnace, in which a remaining portion is comprised of copper and an unavoidable impurity. And hence there is obtained an ingot by casting the same with the cooling rate between 0.1° C. per second and 100° C. per second. Further, there is performed the process of treating with heat for homogenizing the same at between 900° C. and 1050° C. for between a half hour and ten hours. And then thereafter there is performed the process of hot working for the same with the reduction in area of not less than 50% at the processing temperature of not lower than 650° C. Still further, there is performed thereafter the water quenching, and then there is performed the facing in order to remove an oxidizing scale thereon. Still further, the process of cold working is performed with the reduction in area between 50% and 98%, there is performed the solution heat treatment at the temperature between 800° C. and 1000° C., another process of cold working is performed with a reduction in area of R1% in the table, there is performed the heat aging precipitation treatment at the temperature between 400° C. and 650° C., a process of finishing cold working is performed with a reduction in area of R2% in the table, and the process of annealing to be heat treated for refining is performed at the temperature between 200° C. and 450° C. with the amount of time for between five seconds and ten hours. The copper alloy materials is produced, and then a part of each of the obtained copper alloy materials thereby is treated as individual sample materials. Furthermore, there are shown the obtained results in Table 5-2 and Table 5-3.
As it is obvious according to Table 5-2, the present invention samples 5-1 through 5-3 are superior in the yield strength thereof, the electrical conductivity thereof, the yield stress relaxation characteristic thereof and the bending workability thereof. On the contrary it is not desirable in the case of such as shown in the comparative samples 5-1 due to the strength thereof as lower, of which the sum of the R1 and R2 is lower than 5%. Moreover, it is not desirable either in the case of such as shown in the comparative samples 5-2 of which the sum of the R1 and R2 is larger than 65%, because that is inferior in the yield stress relaxation characteristic and in the bending workability.
At first, the elements are mixed to obtain compositions as shown in Table 5-1 according to Example 5. Moreover, an alloy is melt in a high frequency melting furnace, so that a remaining portion is comprised of copper and an unavoidable impurity. The alloy is cast to obtain an ingot with the cooling rate between 0.1° C. and 100° C. per second. Further, there is performed the process of treating with heat for homogenizing the same at between 900° C. and 1050° C. for between a half hour and ten hours. And then thereafter there is performed the process of hot working for the same with the reduction in area of not less than 50% at the processing temperature of not lower than 650° C. Still further, there is performed thereafter the water quenching, and then there is performed the facing in order to remove an oxidizing scale thereon. Still further, there is performed the process of cold working with the reduction in area between 50% and 98%, there is performed the solution heat treatment at the temperature between 800° C. and 1000° C., there is performed a heat aging precipitation treatment at the temperature of T8° C. as shown in Table 6-1 and Table 6-2 with an amount of time for four hours, there is performed another process of cold working with the reduction in area between 5% and 50%, there is performed another heat aging precipitation treatment at the temperature of T10° C. as shown in the tables with the amount of time for four hours, there is performed a process of finishing cold working with the reduction in area between 5% and 50%, and then there is performed the process of annealing to be heat treated for refining at the temperature between 200° C. and 450° C. with the amount of time for between five seconds and ten hours. Accordingly, the copper alloy materials are obtained, and then a part of each of the obtained copper alloy materials is treated as individual sample materials.
Still further, the characteristics of the yield strength (YS), the electrical conductivity (EC), the stress relaxation rate (SR), the average crystalline grain diameter (GS), the bending workability (R/t), the constituent elements of the second phase, the particle density thereof, or the like are examined regarding each of the sample materials similar to the above mentioned examples. Furthermore, there are shown the obtained results in Table 6-1 and Table 6-2.
As it is obvious according to Table 6-1, the present invention samples 6-1 and 6-2 are superior in the yield strength thereof, the electrical conductivity thereof, the yield stress relaxation characteristic thereof and the bending workability thereof. On the contrary, it becomes clear that it is not desirable in the case of the comparative samples 6-1 and the comparative samples 6-2 as shown in Table 6-2 that individually have the T10 as higher than the T8 as the temperature of the heat aging precipitation treatment respectively, because the function of the precipitation hardening thereby is not sufficient, and then because the strength thereof becomes lower.
At first there is performed a mixing of the elements in order to obtain the content and the composition as shown in the Table 5-1 according to Example 5 as similar. Moreover, there is performed a dissolution thereafter for an alloy by making use of the high frequency melting furnace, in which a remaining portion is comprised of copper and an unavoidable impurity. And hence there is obtained an ingot by casting the same with the cooling rate between 0.1° C. per second and 100° C. per second. Further, there is performed the process of treating with heat for homogenizing the same at between 900° C. and 1050° C. for between a half hour and ten hours. And then thereafter there is performed the process of hot working for the same with the reduction in area of not less than 50% at the processing temperature of not lower than 650° C. Still further, there is performed thereafter the water quenching, and then there is performed the facing in order to remove an oxidizing scale thereon. Still further, there is performed a heat aging precipitation treatment at the temperature of T5° C. as shown in Table 7 for four hours, there is performed the process of cold working with the reduction in area between 50% and 98%, there is performed the solution heat treatment at the temperature between 800° C. and 1000° C., there is performed the other process of cold working with the reduction in area between 5% and 50%, there is performed another heat aging precipitation treatment at a temperature between 400° C. and 650° C., there is performed the process of finishing cold working with the reduction in area between 5% and 50%, and then there is performed a process of annealing to be heat treated for refining at a temperature between 200° C. and 550° C. with the amount of time for between five seconds and ten hours. The copper alloy materials are produced, and then a part of each of the obtained copper alloy materials is treated as individual sample materials.
Still further, there are performed the examination on the characteristics of the yield strength (YS), the electrical conductivity (EC), the stress relaxation rate (SR), the average crystalline grain diameter (GS), the bending workability (R/t), the constituent elements of the second phase, the particle density thereof, or the like, regarding each of the sample materials as similar to that according to the above mentioned examples. Furthermore, there are shown the obtained results in Table 7.
As shown in Table 7, it becomes able to obtain the density of the second phase as higher, to design the crystalline grain diameter thereof as smaller, and then to obtain the bending workability thereof as further excellently, in the case of performing the heat aging precipitation treatment (5) at the temperature between 400° C. and 800° C.
According to the present invention, the copper alloy material is applicable to a lead frame for an electrical and electronic device, a connector, a material for a terminal, or the like, and more specifically to such as a connector or a material for a terminal to be made use for such as mounting on a motor vehicle, a relay, a switch, a socket, or the like.
In the embodiments described above, the present invention will not be limited to every detail of the description as far as a particular designation, and it should be interpreted widely without departing from the scope of the present invention as disclosed in the attached claims.
Furthermore, the present invention claims the priority based on Japanese Patent Application No. 2007-086026, that is patent applied in Japan on the twenty-eighth day of March 2007, and on Japanese Patent Application No. 2008-085013, that is patent applied in Japan on the twenty-seventh day of March 2008, and the entire contents of which are expressly incorporated herein by reference.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2007-086026 | Mar 2007 | JP | national |
| 2008-085013 | Mar 2008 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2008/056196 | 3/28/2008 | WO | 00 | 3/25/2010 |
