JPH036214B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for manufacturing a high-strength copper-based alloy having excellent strength and conductivity and suitable for use as a conductive spring material. (Prior art) A typical conductive spring material with excellent strength and conductivity is a precipitation hardening alloy of 1.8% Be, 0.25% Co, and the balance Cu specified as alloy number C1720 in JISH3130. However, since it contains a large amount of expensive Be, it has the disadvantage that the combined price is extremely high. On the other hand, based on Cu, B,
An alloy containing antimetallic elements such as Si, P, Ge.Te, etc. and Be or S is rapidly solidified from a molten state to obtain particle size.
A new attempt to improve conductivity, strength, hardness, etc. by creating a rapidly solidified structure of 0.5 to 15 μm is disclosed in Japanese Patent Publication No. 43895/1983. However, this alloy is not suitable as a conductive spring material because it contains a large amount of semi-metallic elements, resulting in poor conductivity, insufficient hardness and strength, and low elongation and brittleness, resulting in poor bending formability. It lacked practicality and was inferior to conventional precipitation hardening type Cu-Be alloys. (Problems to be solved by the invention) The present invention solves these conventional problems,
In addition to lowering the Be content and lowering the formation price, the rapid solidification method is used to achieve a finer structure, and the properties required for conductive spring materials, such as hardness, strength, and conductivity. This was completed with the aim of creating a high-strength copper-based alloy and its manufacturing method that can fully satisfy the following requirements. (Means for solving the problem) The first invention of the present application has Be0.15 to 1.0% (weight%,
(same below), Ni0.5-6.0%, Si0.2-0.9%, balance Cu
In the rapidly solidified structure, the atomic ratio of Be, Ni, and Si is 1:2.8 to 3.2:0.8 to 1.2, and the crystal grain size is 0.2 to 25 μm.
By increasing the precipitation sites through processing and uniformly and finely dispersing the precipitates after aging treatment, we achieved a Bitkars height of 300.
The purpose of this invention is to provide a high-strength copper-based alloy that is characterized by having the above-mentioned properties. In addition, the second invention of the present application has Be0.15 to 1.0%, Ni0.5
~6.0%, Si0.2~0.9%, remainder Cu and unavoidable impurities, with an atomic ratio of Be, Ni, and Si of 1:2.8~
3.2: 0.8~1.2 alloy from molten state to 500℃/
The crystal grain size is 0.2~25μ by rapid solidification at a speed of more than seconds.
The gist of this article is a method for producing a high-strength copper-based alloy, which is characterized by forming a rapidly solidified structure of m, followed by cold working of 95% or less, and then aging precipitation treatment to uniformly and finely precipitate intermetallic compounds. It is something to do. The present invention exhibits aging precipitation behavior as described above.
By rapidly cooling and solidifying the Cu-Be-Ni-Si alloy from the molten state, extremely fine rapid cooling is achieved by dissolving excessive amounts of solute atoms such as Be, Ni, and Si in the matrix, which is impossible with equilibrium solidification. After obtaining a solidified structure, it is subjected to cold working to generate processing defects in the metal structure, and then subjected to aging precipitation treatment to uniformly and finely precipitate a large amount of intermetallic compounds, thereby improving hardness, strength, This has succeeded in improving bending formability. Next, each component of the present invention will be explained in more detail. Be in the copper-based alloy of the present invention is a basic element for producing precipitation hardenability, and if it is less than 0.15%, the precipitation hardenability is insufficient and no improvement in mechanical strength can be obtained; If it exceeds the amount, the formation price will increase and the purpose of the present invention will not be achieved, and even by the rapid solidification method, the whole will not be able to be dissolved in the matrix, and the effect of improving alloy properties commensurate with the increase in content will not be obtained. Therefore, the content should be in the range of 0.15 to 1.0%, and in particular, the range of 0.4 to 0.8% is optimal. Next, like Be, Ni is also an element that imparts precipitation hardenability, and if it is less than 0.5%, the precipitation hardenability is insufficient, and if it exceeds 6.0%, there will be parts that cannot be dissolved into the matrix during rapid solidification. In addition to this, it also deteriorates the conductivity, so it is necessary to set the content to 0.5 to 6.0%, and a range of 2.0 to 5.0% is particularly preferable. In addition, Si is not only effective in improving mechanical strength without increasing expensive Be by precipitating intermetallic compounds together with Ni, but also improves the castability, slag separation, oxidation resistance, etc. of the alloy. It is also an important element for the purpose of achieving this, and at least 0.2% or more is required, but if it exceeds 0.9%, the conductivity and rolling workability will deteriorate significantly, so 0.2 to 0.9
%, particularly preferably 0.4 to 0.8%. These Be, Ni, and Si have an atomic ratio of 1:1 in order to approximate the stoichiometric composition of the intermetallic compounds that contribute to strengthening.
2.8~3.2: Set in the range of 0.8~1.2. Such an alloy is instantaneously cooled and solidified from a molten state at a high speed exceeding 500° C./second by, for example, being poured between rotating rollers. As a result of such rapid solidification, a fine rapidly solidified structure with a grain size of 0.2 to 25 μm is obtained, and as mentioned above,
A large amount of elements such as Be, Ni, and Si, which cannot be solid-solubilized by equilibrium cooling, is solid-solubilized in the matrix, and hardly any coarse precipitates that do not contribute to strengthening are formed. In the present invention, this structure is formed by rolling etc.
After applying cold working of 95% or less to create processing defects in the structure, and further adding solution treatment at 550 to 1000°C and cold working of 80% or less as necessary,
Aging precipitation treatment is performed at 250-500℃. Through these treatments, the number of precipitation sites due to processing increases in the rapidly solidified structure, and intermetallic compounds of Be, Ni, and Si precipitate uniformly and finely, and the hardness of the material increases as shown in the data of the later examples. In addition to achieving a Bitkers hardness of 300 or more, tensile strength and bending workability are significantly improved. In particular, in the present invention, excessive amounts of Be, Ni, and Si elements are dissolved in the matrix by the rapid solidification method, so that uniform and fine intermetallic compounds are precipitated all at once in a short time by the aging precipitation treatment. , hardness, strength, bending workability, etc. can be significantly improved. In addition, in the present invention, even when solution treatment is performed, Be, Ni, and Si dissolved in solid solution by the rapid solidification method effectively control grain growth.
The grain size of the final structure does not exceed 25 μm. In addition, the degree of cold working was set to 95% or less because
This is because it is necessary to sufficiently generate processing defects in the structure, and the reason why the crystal grain size is set to 0.2 to 2.5 μm is because it is difficult to generate crystals smaller than 0.2 μm, and conversely, it is difficult to generate crystals smaller than 25 μm. This is because ductility and bending formability decrease. As described above, the alloy of the present invention has excellent hardness and strength despite its low beryllium content, and has a dense structure that provides excellent ductility and bending formability. Since it does not contain carbon, it has high conductivity suitable as a conductive spring material. (Example) Alloys of various compositions No. 1 to No. 7 shown in Table 1 were sprayed between rollers rotating at high speed, and
A thin plate with a thickness of 0.35 mm was prepared by rapidly solidifying the material from the molten state at a rate of at least ℃/second. After processing this through the processing steps indicated by symbols a, b, c, d, etc. in Table 1, the Vickers hardness, tensile strength, elongation, etc.
The electrical conductivity was measured and recorded in the same table. In addition, Table 2 shows the measured values for alloys whose alloy compositions are outside the range of the present invention when processed in the same manner as shown in Table 1. is within the scope of Japanese Patent Publication No. 60-43895 cited as the prior art. The contents of the treatment steps indicated by symbols a to h are summarized in Table 3.

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[Table] (Effects of the invention) As is clear from the above description, the present invention has the following effects:
In addition to lowering the formation price by lowering the Be content, the combination of rapid solidification, cold working, and aging precipitation treatment improves the various properties required for conductive spring materials, such as hardness, strength, and bending formability, in a well-balanced manner. This is because the conventional Cu-Be
As it eliminates the problems of alloys and conventional rapidly solidified alloys, it will greatly contribute to the development of industry.

Claims (1)

[Claims] 1 Be0.15 to 1.0% (weight%, same hereinafter), Ni0.5
~6.0%, Si0.2~0.9%, remainder Cu and unavoidable impurities, with an atomic ratio of Be, Ni, and Si of 1:2.8~
3.2: 0.8~1.2, and the crystal grain size is 0.2~
A high-strength copper-based alloy characterized by increasing the number of precipitation sites through processing and uniformly and finely dispersing the precipitates after aging treatment in a rapidly solidified structure of 25 μm, giving it a Bitkers height of 300 or higher. 2 Be, Ni, Si content: Be0.4~0.8%, Ni2.0
~5.0% and Si0.4~0.8% in claim 1
High-strength copper-based alloy as described in . 3. The high-strength copper-based alloy according to claim 1, which has a tensile strength of 100 Kg/cm ² or more and a Vickers hardness of 350 or more. 4 Be0.15~1.0%, Ni0.5~6.0%, Si0.2~0.9%,
The remainder consists of Cu and unavoidable impurities, Be, Ni,
An alloy with an Si atomic ratio of 1:2.8 to 3.2:0.8 to 1.2 is rapidly solidified from a molten state at a rate of 500°C/second or more to obtain a rapidly solidified structure with a crystal grain size of 0.2 to 25 μm, and then the crystal grain size is 95% or less. A method for producing a high-strength copper-based alloy, which comprises performing cold working and further precipitating intermetallic compounds uniformly and finely by aging precipitation treatment. 5 After cold working, perform annealing or solution treatment at 550 to 1000℃ and cold working to 80% or less, and then 250
The method for producing a high-strength copper-based alloy according to claim 4, wherein the aging precipitation treatment is performed at ~550°C.