JPH0123526B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a technology for manufacturing a molded part made of a beryllium copper alloy material. (Prior Art) Beryllium copper alloy is an excellent material having high strength and high conductivity, and is widely used in many products such as connectors and relays. In recent years, there has been an increasing demand for smaller products, and therefore beryllium-copper alloy materials are also required to have formability sufficient to withstand severe processing. Conventionally, rolled plates of beryllium copper alloys processed into molded parts have been repeatedly cold rolled and annealed after casting and hot rolling of raw materials, followed by solution treatment and then cold rolling. It is common to manufacture Furthermore, the above-mentioned rolled plate of beryllium copper alloy is processed into a required part molded body in one of the following ways. In the first aspect, the rolled sheet of beryllium copper alloy is subsequently subjected to age hardening treatment, delivered to the user as a so-called mill-hardened material, and formed into the required part shape by processing including bending at the user's factory. It is something. In this case, the obtained molded body is often incorporated into a product as a part as it is. The second aspect is to deliver the rolled sheet of beryllium copper alloy to the user as is, form it into the required part shape at the user's factory in the same way as above, and then return it to the user's factory or the material manufacturing factory for aging. A hardening process is performed to complete the part as having the required strength. In either case, the cold-rolled sheet treatment that follows the solution treatment is a factor that has a large effect on the material properties, and is responsible for improving product strength, preventing deformation after aging, and promoting aging precipitation. It is intended. (Problems to be Solved by the Invention) As mentioned above, when performing cold rolling treatment following solution treatment, if the reduction rate is set to a high value, the rolled plate centering on the bending axis parallel to the rolling direction will
The bending properties in the 90° direction deteriorate, and even when molding into a desired part shape prior to age hardening, the degree of freedom in molding is significantly impaired. Therefore, cold rolling at a reduction rate of 60% or more is not normally performed for materials exhibiting a particularly marked tendency to work hardening. In other words, the number of repetitions of cold rolling and annealing performed before solution treatment must be increased, making it difficult to reduce manufacturing costs. On the other hand, for materials subjected to age-hardening treatment as mill-hardened materials, the higher the strength after aging, the lower the elongation and the worse the formability, which significantly impairs the freedom of forming into part shapes, especially bending. It turns out. In order to secure the required formability, it was necessary to sacrifice the high strength that is the original function of beryllium-copper alloys. (Problems to be Solved by the Invention) The purpose of the present invention is to bend a material whose formability has deteriorated due to cold working at a reduction rate of 20% or more to a small radius of curvature during processing and forming of parts. The object of the present invention is to make it possible to easily achieve maximum strength by aging a beryllium-copper alloy material that can be improved to withstand stress after being processed into a desired part shape. (Means for solving the problem) To achieve this objective, the present invention provides Be: 0.2
~0.8wt%, and Ni and/or Co: 0.3~4.0wt
After applying solution treatment to a rolled sheet of Be-Cu alloy containing % and the remainder being substantially Cu, the rolling reduction rate is 20%.
After the above cold working, the temperature is 250℃~550℃.
The formability of the Be-Cu alloy material is restored by annealing at a temperature of
- Cu alloy material is formed into the required part shape through processing including bending, and then aged at a temperature of 350℃ to 550℃ to achieve the required product strength. FIG. 1 is a flowchart of a manufacturing process comparing the prior art described above and the present invention. In the conventional technology, the cold-rolled plate itself after solution treatment of beryllium copper alloy is subjected to the required forming processing and then subjected to age hardening treatment, or the mill-hardened material obtained by applying age hardening treatment first is used. The product is made by performing the necessary molding processing. As mentioned above, such a manufacturing process is accompanied by various problems. In contrast, in the present invention, cold rolling after solution treatment is followed by annealing at a predetermined temperature to release part of the processing strain and restore formability. By molding a beryllium copper alloy material with excellent properties into a desired part shape and then subjecting it to an age hardening treatment, it is possible to manufacture a product with the desired high strength. (Operation and Reason for Limitation) In the present invention, as described above, Be: 0.2
~0.8wt%, and Ni and/or Co: 0.3~4.0wt
% and the remainder is substantially Cu. The reasons for limiting each component are as follows. First, if the amount of Be added is less than 0.2wt%, sufficient precipitation hardening cannot be achieved;
It was confirmed that if the amount of Be added exceeds 0.2 to 0.8 wt%, the strength could not be improved in accordance with the increase in the amount of Be added. Next, if the amount of Ni and/or Co added is less than 0.3wt%, sufficient precipitation hardening will not be achieved;
It was confirmed that formability deteriorates when the amount exceeds 4.0wt%, so the amount of Ni and/or Co added was reduced to 0.3%.
~4.0wt%. In the present invention, Be--Cu having the composition as described above is used.
The reason why the rolling reduction ratio of cold working applied to a rolled alloy plate after solution treatment is set to 20% or more is as follows. In other words, if the rolling reduction is less than 20%, the formability will not deteriorate significantly, and there is no need to recover the formability through annealing.On the other hand, the higher the rolling reduction, the more the solution This is also because it becomes possible to reduce the number of repetitions of cold working and annealing before treatment. In addition, in the present invention, the reason why the temperature range of annealing performed between cold rolling after solution treatment and forming into the required part shape is set to 250 ° C to 550 ° C.
If the temperature is below ℃, the formability cannot be recovered sufficiently, and if it exceeds 550℃, it will become over-aged.
This is because sufficient strength cannot be obtained by age hardening treatment after processing and forming. Furthermore, in the present invention, the temperature range of the age hardening treatment performed after molding into a predetermined part shape is 350°C.
The reason for setting the temperature to 500°C is that precipitation hardening cannot be obtained at temperatures below 350°C, while electrical conductivity improves when the temperature exceeds 500°C, but an over-aged state occurs and sufficient strength cannot be obtained. (Example) Examples (1) to (16) of the present invention and comparative example (17)
The component compositions, manufacturing conditions, and mechanical properties of (24) are as shown in Table 1.

[Table] Samples (1) to (24) listed in Table 1 were prepared under different manufacturing conditions after being subjected to the solution treatment in the process shown in Figure 1 in a known manner. This is what I did. In Table 1, formability is shown before age hardening treatment.
After bending a rolled sheet of Be-Cu alloy at 180°C around the bending axis parallel to the rolling direction, the safe bending radius R is determined based on the presence or absence of cracks at the bent part, and this value is determined by the sheet thickness t. The smaller the value, the more severe the forming process including bending process with a small radius of curvature can be withstood. As is clear from Table 1, samples (1) to (16) according to the examples of the present invention all had excellent formability and strength (after age hardening determined according to JIS Z2241).
0.2% yield strength). To explain the comparative example samples, comparative example samples (17), (19), and (21) are the same as the example samples (5) to (8), and the comparative example samples (18),
Samples (20) and (22) have the same composition as Example samples (10) and (11), respectively. Comparative example samples (17) and (18) have a low rolling reduction ratio during cold working. In other words, the reduction rate is 15%
In the case of , good formability can be obtained without annealing, but it is clear that the 0.2% proof stress value after aging is lower than the value of the example sample with the same composition. Comparative example sample (19) was annealed at a high temperature, so the precipitate nuclei became coarser, and after aging it was 0.2%
The yield strength value has decreased, and since sample (20) was annealed at a low temperature, the recovery of formability after annealing is insufficient. Comparative example sample (21) was aged at a high temperature, resulting in an overaged state, and sample (22) was aged at a low temperature, resulting in an unaged state.
In both cases, the yield strength value decreased by 0.2%. Furthermore, Comparative Example Sample (23) and Sample (24) contain too little beryllium and cobalt, respectively, so that sufficient strength cannot be obtained. Next, Table 2 shows the example samples (10) and (11) mentioned above.
Formability after cold working a sample with the same composition as 20% to 90%, followed by annealing at 400℃, and 0.2 after aging treatment at 400℃.
% proof stress value.

【table】

[Table] As is clear from Table 2, formability deteriorates as the rolling reduction during cold working increases, but by annealing according to the present invention, it recovers to a highly practical R/t value. ing. (Effects of the Invention) According to the present invention, by setting a high rolling reduction rate during cold working after solution treatment, it is possible to effectively improve strength after aging, prevent deformation, etc. This provides the advantage that deterioration in formability, which was conventionally thought to be unavoidable when the reduction rate is high, can be accurately prevented by annealing at a predetermined temperature. In addition, by increasing the reduction rate during cold working after solution treatment, for example, if the reduction rate is 80%, if the final product plate thickness is 0.2 mm, solution treatment will be performed with the plate thickness being 1.0 mm. This makes it possible to achieve economical advantages such as the ability to reduce the number of repetitions of rolling and annealing before solution treatment compared to conventional cold working at a low reduction rate. Furthermore, by performing annealing in a restrained state, the material shape is corrected and at the same time aging precipitation is promoted to some extent, so shrinkage deformation that occurs during aging treatment after forming into a part shape can be effectively prevented. It is possible.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing each step in the manufacturing method of the present invention in comparison with the prior art.

Claims (1)

[Claims] 1 Be: 0.2 to 0.8 wt%, and Ni and/or
A rolled sheet of Be-Cu alloy containing 0.3 to 4.0 wt% of Co, with the remainder being substantially Cu, is subjected to solution treatment, then cold worked at a reduction rate of 20% or more, and then The Be-Cu alloy material obtained by annealing at temperatures between ℃ and 550℃ is further formed into the desired part shape by processing including bending.
A molded part made of a beryllium copper alloy material, characterized in that it is obtained by aging at a temperature of 350°C to 500°C. 2 Be: 0.2 to 0.8wt%, and Ni and/or
A rolled sheet of Be-Cu alloy containing 0.3 to 4.0 wt% of Co, with the remainder being substantially Cu, is subjected to solution treatment, then cold worked at a reduction rate of 20% or more, and then The Be-Cu alloy material obtained by annealing at temperatures between ℃ and 550℃ is further formed into the desired part shape by processing including bending.
A method for producing a molded part made of a beryllium copper alloy material, characterized by aging at a temperature of 350°C to 500°C.