JPS63235455A - Manufacture of high-strength copper alloy - Google Patents

Abstract

PURPOSE:To inexpensively manufacture a high-strength copper alloy excellent in fatigue strength without using Be as a rare resource, by subjecting a molten phosphor bronze with a specific composition to rapid solidification. CONSTITUTION:A molten phosphor bronze which has a composition consisting of, by weight 9-20% Sn, 0.01-0.5% P, and the balance Cu or further containing 0.01-1.0%, in total, of at least one or more elements among Ni, Zn, Fe, Ti, B, Co, Mn and Zr is cooled rapidly by means of a rapidly rotating water-cooled roll, etc., at 10<2> deg.C-10<5> deg.C/sec cooling rate so as to be formed into a sheet-like ingot, and is then cold-rolled into a metal sheet of 0.3mm thickness without homogenizing annealing. The metal sheet is annealed at 500 deg.C for 1hr and subjected to final finish cold rolling at 33% draft and then to low temp. annealing treatment at 250 deg.C for 1hr. In this way, the high-strength copper alloy having superior cold workability, suitable for use in switch, relay, etc., to be subjected to repeated stress, and excellent in fatigue strength can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a method for manufacturing a high-strength copper alloy with good scissoring properties suitable for applications where 1% repetitive stress is applied in relation to switches and relays. It is.

[Conventional technology]

Typical high-strength copper alloys commonly used in the market include 2, for example, the magazine 2 Copper Elongation Technology Study Group gVo.
There is a C1720 alloy (beryllium copper alloy) shown in 1.9(19'l0)PID9~P1)6.

This alloy is a scarce resource and is difficult to secure a stable supply because it is expensive.
There is a problem in terms of cost because it contains

On the other hand, as an inexpensive spring material, there is a phosphor bronze alloy containing ann and a small amount of P in Cu, and its mechanical properties are 2.
For example publication: A8TM 8peC, Tech.

As also shown in Pub, No. 183 (1958).

It has a tendency to increase as the Sn content increases.

However, when the amount of Sn increases, the crystallization of compound phases 9, such as δ and β phases, which are hard and have poor malleability, and the appearance of the transport segregation phenomenon of Sn, deteriorate the workability to the extreme. It has the disadvantage that it cannot be cold-opened and can only be used as a cast iron. Therefore, the maximum 8n content of the alloys currently used as spring materials is 9.
It is only about %. For this reason, there is a large difference in properties from CI 720 alloy.

There is a demand for the emergence of an alloy that fills this gap.

[Problem that the invention seeks to solve]

Without using the expensive B5, which is a scarce resource and difficult to obtain in a stable supply, it is now possible to obtain a phosphor bronze alloy that can be stably supplied, has excellent mechanical properties and workability, and has sufficient properties as a spring material. The problem was that there was no.

This invention was made in order to eliminate the above-mentioned mA, and to improve the structure and cold workability of phosphorus steel thread alloy without using N6, which is a scarce resource and difficult to secure stable supply. The purpose of this study is to obtain a high-strength copper alloy with sufficient properties as a spring material.

[Means for solving problems]

The high-strength copper alloy of the present invention contains Sn in an amount of 9 to 20 mm, P in an amount of 0.01 to O, S, and the balance is Cu at a rate of 1051:/
It is produced by rapid solidification at a cooling rate of less than sec.

[Effect]

By rapidly solidifying the molten metal at a cooling rate of 102 r/sec or more and less than 105° C./sec when producing the alloy in one lump, the occurrence of reverse segregation is suppressed.

Since the compound phase can be uniformly dispersed in the IJ lux, the two-structure structure and cold workability can be improved.

〔Example〕

Examples of the present invention will be described below.

The invention material was produced using an experimental rapid solidification equipment consisting of twin cast iron rolls with a diameter of 200 m1) and capable of internal water cooling. The manufacturing conditions are as follows: (1) The rotation type of the cooling roll is 1
Orpm, (The temperature of pouring into the II roll was set to 50"C higher than the melting point of the alloy, and the roll gap was set to 1.8 mm. The resulting ingot had a thickness of 1.8 fins and a width of The ingot was 1021:/s, which is faster than conventional continuous casting or batch casting.
Because it is continuously rapidly solidified at a cooling rate of ec or more and less than 105 r:/sec, the appearance of dendrite braiding and reverse segregation is suppressed, and the compound phase is kept thin and uniformly dispersed in the IJ lux. The processability is extremely good. These ingots can be processed all at once without homogenization annealing.
After cold rolling to a thickness of 0.3M.

Following pheasant dulling at 500°C for 1 hour, the plate was finished to a plate thickness of 0.2u at a cold working rate of 33g6. Then 250 and 1
It was subjected to low-temperature annealing treatment for several hours and was used as a sample for measuring the mechanical properties.

Table 1 summarizes the characteristic values of this invention material and comparative material.

As is clear from these results, by manufacturing a Cu-an alloy containing Sn of 996 or more by rapid solidification as in the present invention, the cold workability is significantly improved, making it suitable as a spring material. It can be seen that a high-strength copper alloy can be obtained. For example, when comparing the properties of the 05210 alloy (comparative material) of Sample 7III1), which is generally widely used as a spring material, and Sample A3 (inventive material), which contains about twice as much Sn as that of Sample 7III1).

Sample A3 has an increase in tensile strength of about 50% and a spring limit value of about 1)0%. On the other hand, an improvement effect was also observed on the characteristics of spring material, which is considered a summer material, and the number of repetitions was
A value of 32 kgf/''2 was obtained for the wear strength at N=107 times, which is in the middle between the 05210 alloy and the 01720 alloy.

These improvements in mechanical properties are due to the fact that the 8n content is increased compared to conventional products, resulting in increased solid solution hardening ability and work hardening ability, and the uniform dispersion of fine compounds in the matrix. In particular, the improvement in fatigue properties is thought to be due to the fine compounds dispersed in the matrix inhibiting the propagation of cracks. The content of an is 93[1
) - Mechanical properties are insufficient under scratch removal, 203
i[i4 or higher, although the mechanical properties improve, C
Since the cost advantage is weakened and the workability is lower than that of l720 alloy, a range of 9 to 20131-ji% is preferable. In addition, if the P content is less than 0.01 ms, it has no practical effect as a deoxidizing agent, and o, 53B1*
Even if it is contained above, there is no change in the effect, and in order not to lower the electrical conductivity, it is better to have a smaller amount.The range of 0.01 to 0.5% by weight is better.

Table 2 shows the effects of trace amounts of added elements.

When compared with the Cu-8n-P-based sample/l&4, there is almost no difference in the tensile strength, spring limit value, and fatigue strength of sample A5.
Mn, Zn, and B do not adversely affect these properties, indicating that they are effective as deoxidizing agents.

However, as the amount added increases, it becomes brittle and affects workability and conductivity, so an upper limit is set. on the other hand,
When a sample of Muro~49 is softened.

Additive elements such as Nl * Fee co, 'rig zr contribute to grain refinement 2 and increase strength, and are particularly effective in improving fatigue properties, and the upper limit of this contributes to the improvement of formability. Restrictions were placed on The content of these trace elements is 0.01 to 1.0 ozy* or more in total since it lowers the conductivity if it is included. The amount of OJi is preferably less than % quantum. Further, in consideration of the above-mentioned points, the content of each trace element is practically desirably within the following ranges.

Ni-o, o t ~o, s electrical capacity 96 Zn-
"0.01-0.35 pagestg6Fe = 0.01-0
．． 153 [child% T i = 0. O2N2.5 1l
q6B...o, oot~0.1n amount% cm・
・・・・・・0.01～0.5mu% gallery・・・・・・O,
OS~0.43 [Amount% Zr...0.01~
The cooling rate of the metal in the bath water is the result of various experiments.

If it is less than 102 r:/sec, the one-block molding is no different from that obtained by the conventional casting method, and good workability cannot be obtained.

Moreover, if it is 1051:/sec or more, the plate thickness that can be manufactured becomes extremely thin, making it difficult to put it into practical use.

A range of 102r/sec or more to less than 5t-/sec is preferable.

For reference, the manufacturing method for this invention alloy is Cu-8
Not only n-based alloys, but also Nf-Be-A1, which is known as a difficult-to-process material because compound phases with poor malleability tend to crystallize.
．． Similar effects can be obtained even when applied to Cu-Ni-Mn, Cu-Ti alloys, etc.

〔Effect of the invention〕

As described above, according to the present invention, 9 to 20 pages contain P in an amount of 8n and Q, 01 to 0.5n in amount%, and the balance is C.
When U is produced by quenching vertically at a cooling rate of 10 r/see or more and less than 105 r/sec, the cold workability of the two structures is significantly improved compared to K.
Suitable for applications such as switches and relays that are subject to repeated stress, we can provide a stable supply at low prices.

m*It has the effect of obtaining a high-strength copper alloy that is suitable for labor.

Claims (2)

[Claims] (1) 9-20 wt% Sn and 0.01-0.5 wt%
A molten metal containing 10^2 P and the remainder Cu
A method for producing a high-strength copper alloy by rapid solidification at a cooling rate of 10^5 °C/sec or more and less than 10^5 °C/sec. (2) The molten metal is Ni, Zn, Fe, Ti, B, Co,
At least one or more types of Mn and Zr combined from 0.01 to
The method for producing a high-strength copper alloy according to claim 1, which contains 1.0% by weight.