JPS647148B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a beryllium copper alloy that has high electrical conductivity and high strength and is used for connectors, relays, etc. The present invention relates to a method for producing a beryllium-copper alloy that has excellent strength and workability. (Prior Art) Various beryllium-copper alloys have been widely used as wrought materials for electronic parts, etc., due to their high electrical conductivity and high strength properties. In manufacturing these beryllium copper alloys, as shown in the flowchart in Figure 3, after obtaining an ingot consisting of specified Cu, Be, and other subcomponents, for example, 750
After performing solution treatment at ~950° C. and cold working, an age hardening treatment was further performed to obtain the desired beryllium copper alloy. (Problems to be Solved by the Invention) However, in the conventional alloy manufacturing method described above, strength and workability are improved by solution treatment due to undissolved intermetallic compounds generated between Be and sub-additional components. This is carried out to improve the
Many coarse undissolved precipitated grains were observed, and there was a problem that the strength and workability could not be sufficiently improved. In addition, at this time, it is possible to improve the strength by simply increasing the solution temperature by dissolving some of the undissolved precipitates, but at the same time, this causes the grain size of the base to become coarser, which causes problems in workability. There were also some drawbacks. The purpose of the present invention is to eliminate the above-mentioned problems, to improve homogeneity and increase strength by refining most of the conventionally coarse undissolved precipitated grains to 0.3 μm or less and dispersing them in the matrix. It is an object of the present invention to provide a method for producing a beryllium-copper alloy that can obtain an alloy having good workability. A further object of the present invention is to provide a method for producing a beryllium-copper alloy that can achieve high strength and workability by suppressing grain growth during annealing using undissolved precipitated grains that are uniformly and finely dispersed. (Means for solving the problem) The method for producing the beryllium copper alloy of the present invention is based on Be0.05
~2.0% by weight, at least one of Co and Ni 0.1~
An ingot is obtained by melting an alloy consisting of 10.0% by weight and the remainder substantially Cu, and this ingot is subjected to solution treatment at a temperature of 800 to 1000℃, cold worked, and then age hardened. It is characterized by annealing at a temperature lower than the solution temperature within the range of 750-950°C. (Function) In the present invention, the main strengthening mechanism is the precipitation of the intermetallic compound of Be and Co or Ni as described above.
First, large precipitate grains are dissolved in the matrix by solution treatment at a higher temperature than conventional methods of 800 to 1000°C, and cold working is added to facilitate the generation of precipitate nuclei. Then, by annealing at a temperature lower than the solution temperature of 750 to 950°C, preferably at a temperature where the difference is 20 to 200°C, part of the solute precipitates, resulting in precipitated grains with a particle size of, for example, 0.3 μm or less. We obtained an alloy with more than 40% dispersed state. In addition, in the alloy of the present invention, the amount of Be added is
The reason why it is limited to 0.05 to 2.0% by weight is that if it is less than 0.05% by weight, the addition effect cannot be obtained, and if it exceeds 2.0% by weight, the cost will be high despite the strength improvement.
Addition of ~0.7% by weight is more preferred. Also, Co
The reason for limiting the amount of at least one of Ni and Ni to 0.1 to 10.0% by weight is that if it is less than 0.1% by weight, the addition effect cannot be obtained, and if it exceeds 10.0% by weight, the processability will deteriorate and no improvement in properties can be expected. Addition of 4.0% by weight is more preferred. Furthermore, the reason why the solution treatment temperature was limited to 800 to 1000℃ is that if the solution treatment temperature is less than 800℃, solid solution of precipitated grains will not proceed, and if it exceeds 1000℃, the temperature will be close to or above the melting point, making production difficult. This is to become. In addition, the annealing temperature varies depending on the solution temperature, required strength, and grain size, but if it is less than 750℃, the amount of precipitation during annealing will increase and the strength after age hardening will decrease, and if it exceeds 950℃, the amount of precipitation will increase. The temperature was limited to 750 to 950°C because the effect of refining the crystal grains of the matrix would be lost. (Example) FIG. 1 is a flowchart showing an example of the method for producing a beryllium copper alloy of the present invention. In this example, an alloy consisting of 0.05 to 2.0% by weight of Be, 0.1 to 10.0% by weight of at least one of Co and Ni, and the balance Cu is first cast to obtain an ingot. The obtained ingot is repeatedly subjected to hot forging, cold rolling, and annealing as necessary to obtain a material, and then this material is subjected to solution treatment at a predetermined temperature between 800 and 1000°C. Thereafter, after performing cold working to form a predetermined shape, annealing is performed for preferably 1 to 5 minutes at a temperature that is preferably 20 to 200°C lower than the solution temperature of 750 to 950°C. Finally, a normal age hardening treatment is performed to obtain a beryllium copper alloy material having the various characteristics of the present invention. An actual example will be explained below. Example 1 Alloys having various compositions shown in Table 1 were cast, hot forged, cold rolled and annealed repeatedly, and then divided into three equal parts. After that, 1 hour each for 5 minutes.
One was solution-treated at the temperature shown in Table 1 according to the process of the present invention (No. 1 to 9), and one was solution-treated at the usual solution temperature shown in Table 1 according to the conventional process (No. No.
Nos. 10 to 18), and in the other case, only solution treatment was performed at the same temperature shown in Table 1 as in the present invention (Nos. 19 to 27).
Regarding the alloys of the present invention (Nos. 1 to 9), the first
After annealing at the temperatures shown in the table, each sample was subjected to 30% cold working. Then, as the safe bending factor for each sample,
A value R/t was determined by dividing the minimum radius of curvature R at which a 90° bend can be made without causing a crack in the direction perpendicular to the rolling direction by the plate thickness t. Furthermore, the tensile strength and fatigue strength (stress 60 kg/
mm ² ) were measured respectively. In addition, in order to investigate the influence of annealing temperature on the present invention, conventional alloys whose annealing temperatures were outside the range of the present invention were subjected to the same treatment as in the present invention at the temperatures shown in Table 1 (Nos. 28 and 29). ), and various properties were similarly measured. The results are shown in Table 1. In addition, the first
In the table, the grain size of the matrix and the percentage of precipitated grains of 0.3 μm or less were visually determined from optical micrographs at the same magnification.

[Table] As is clear from the results in Table 1, 800 to 1000
The alloy of the present invention (No.
1 to 9) have a smaller matrix grain size than other conventional alloys, and the proportion of precipitated grains of 0.3 μm or less is 40%.
As a result, it was found that good tensile strength, formability, and fatigue strength could be obtained. FIGS. 2a and 2b are optical micrographs showing the metal structures of beryllium copper alloys made of Cu-0.4Be-2.0Ni produced by the conventional method and the method of the present invention, respectively. As is clear from FIGS. 2a and 2b, in the alloy of the present invention, the crystal grains of the matrix are fine, and the precipitated grains made of intermetallic compounds are also finely dispersed. (Effects of the Invention) As is clear from the detailed explanation above, according to the method for producing beryllium copper alloy of the present invention,
An alloy of a given composition is solution-treated at a temperature higher than conventional temperatures of 800 to 1000℃, large precipitate grains are dissolved in the matrix, and cold working is applied to facilitate the generation of precipitation nuclei. By annealing at a temperature lower than the solution temperature, preferably at a temperature where the difference is between 20 and 200°C, a part of the solute is precipitated, and 40% or more of the crystal precipitated grains have a grain size of 0.3 μm or less, for example, and are dispersed. state alloy can be obtained. As a result, the alloy obtained by the manufacturing method of the present invention has improved tensile strength, formability, and fatigue strength,
A beryllium copper alloy suitable for electronic parts such as spring materials and connectors that require high conductivity and strength can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing an example of the method for manufacturing the beryllium copper alloy of the present invention, FIGS.
The figure is a flowchart showing an example of a conventional manufacturing method for beryllium copper alloy.

Claims (1)

[Claims] 1. An ingot is obtained by melting an alloy consisting of 0.05 to 2.0% by weight of Be, 0.1 to 10.0% by weight of at least one of Co and Ni, and the remainder substantially Cu; hand
Beryllium is characterized by solution treatment at a temperature of 800-1000℃, cold working, and annealing at a temperature lower than the solution temperature within the range of 750-950℃ before age hardening treatment. Copper alloy manufacturing method. 2 The temperature difference between the solution temperature and annealing temperature is 20 to
A method for producing a beryllium copper alloy according to claim 1, wherein the temperature is 200°C.