JPS61106738A - Conductive spring material - Google Patents

Abstract

PURPOSE:To obtain a conductive spring material having superior characteristic of spring as well as conductivity at low cost, by incorporating specific percentage of Ni, Be, and Si to Cu. CONSTITUTION:The Cu alloy consisting of, by weight ratio, 1.8-3.0% Ni, 0.15-0.35% Be, 0.2-1.2% Si, and the balance Cu with inevitable impurities is manufactured. In this way, the conductive spring manufactured at reduced material cost, gaining high strength and bending formability and having improved property of relaxation of stress can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a low-cost conductive spring material with excellent conductivity and spring properties that is used as a material for electrical equipment such as connectors, switches, and relays.

(Prior art) Typical conductive spring materials with excellent conductivity and spring properties are 5.5 to 9.0% (by weight, hereinafter the same), which is specified as Type 2 or Type 3 in JIS. ) and 0.0
Phosphor bronze contains 3 to 0.3% P, but its conductivity, bending formability, stress relaxation properties, etc. are insufficient for use in recent miniaturized electronic components that require high reliability. Demand for improvement is increasing for reasons such as the following. In addition, one of the conductive spring materials that satisfies these requirements is an alloy with a nominal composition of Cu-0.4%Be-1.8%Ni, but since Be is expensive, the material cost is high. There was a drawback.

(Problems to be solved by the invention) The present invention solves the conventional problems as described above, and
u -0.4% B e -1.8% This was completed with the aim of providing a conductive spring material with excellent cost performance by reducing the cost and e while maintaining the excellent characteristics of the alloy. It is.

(Means of 7 for solving the problem) The present invention includes Ni of 1.8 to 3.0% by weight and 0.15% of Ni by weight.
It consists of ~0.35% Be, 0.2~1.2% Si, the balance Cu and unavoidable impurities,
More preferably 2.0-2.8% Ni and 0.20-2.8% Ni
It is characterized by consisting of 0.25% Be, 0.3 to 1.0% Si, and the remainder Cu and unavoidable impurities. That is, the present invention provides B
In addition to compensating for the decrease in strength due to decreasing the amount of e by increasing the amount of Ni and adding Si, we also reduced the amount of Ni to 1 to reduce grain growth during solution treatment, which is a problem in reducing the amount of I3e.
．． It was developed based on the new knowledge that it can be effectively suppressed by setting the content of phosphor bronze to 8 to 3.0%, and its strength and spring properties are equal to or higher than those of conventional phosphor bronze for springs. This has resulted in a low-cost conductive spring material with excellent mechanical strength, bending formability, stress relaxation properties, and conductivity.

Next, to explain the reason for limiting the content of each alloy component, Ni
If it is less than 1.8%, the coarsening of crystal grains during solution treatment due to the decrease in Be content cannot be prevented, so no improvement in stress relaxation properties can be obtained, and if it exceeds 3.0%, the amount added will increase. 1.1 1.8 to 3.0 because not only does it not improve properties commensurately, it also impairs the rolling workability and bending formability of the material.
% range・Especially 2・θ～□：”(2,a%
The range of is optimal. If Be is less than 0.15%, precipitation hardenability decreases and coarsening of crystal grains during solution treatment cannot be prevented, and if it exceeds 0.35%, the effect of reducing material prices will be reduced, so it should be 0.15~ The content is set in the range of 0.35%, and the range of 0.20 to 0.25% is particularly optimal. Si is an important component to compensate for the decrease in strength due to the decrease in Be content, and if it is less than 0.2%, its effect is not significant, and if it exceeds 1.2%, rolling workability and conductivity are inhibited. Therefore, 0.2 to 1.2%, especially 0.3 to 1.
A range of 0% is preferred. Also, Si is 0.2 to 1
．． By adding within the range of 2%, the castability, slag separation properties, and oxidation resistance of the alloy are greatly improved, and it can also contribute to reducing manufacturing costs.

(Example) Alloys of Examples 1 to 5 and Comparisons 6 to 9 shown in Table 1
(Comparative Example 9 is conventional phosphor bronze for springs) was melted and cast in a high-frequency induction furnace, hot forged, hot rolled, annealed, and cold rolled repeatedly to form a 0.2 w plate''1.6''. °゛0“14
41 Logic, ThLr900"C"ffl,.

After heating for 5 minutes and cooling in water, the material was further rolled by 37% and then aged at 400° C. for 2 hours, and its properties were measured. The results are shown in Table 2. Here, the stress relaxation properties were evaluated by applying a maximum bending stress of 40 kg f/Tsuru 2 to the test piece, holding it at 200''C for 100 hours, releasing the load, measuring the residual stress, and measuring the residual stress rate. Bending formability was evaluated by the ratio R/l of the minimum bending radius R that does not cause cranking and the plate thickness t. Note that θ″ indicates the characteristic value in the rolling direction, and 90° indicates the characteristic value in the direction perpendicular to the rolling direction. .

Table 1 (Weight %) (Effects of the Invention) As is clear from the explanation using the above embodiments, the present invention is more expensive than the conventional Cu -0°4% B e content.
-The material price is significantly lower than that of the 1.8% Ni alloy, and it also achieves high strength and bending formability equivalent to or higher than that of the conventional Ni alloy, as shown in Comparative Example 9. Compared to the properties of phosphor bronze for springs, it has particularly excellent formability in the 90° direction, and is also extremely excellent in electrical conductivity and stress relaxation properties. Therefore, the present invention greatly contributes to the development of industry as it solves the problems of conventional conductive spring materials.

Procedural amendment (voluntary) July 11, 1985 Patent Application No. 228499 2, Name of the invention Conductive spring material 3, Relationship with the case by the person making the amendment Patent applicant address Suda, Mizuho Ward, Nagoya City, Aichi Prefecture Town 2 No. 56 No. 4, Agent 5, Subject of amendment 6, Contents of amendment + 11, On page 3, line 14 of the specification, "stress relaxation characteristics" shall be amended to read "mechanical stress characteristics."

(2) On page 4, line 4 of the specification, the phrase "to compensate" is amended to read "to compensate, to improve elongation, formability, and stress relaxation properties."

(3), page 4, line 16 of the specification, r 0.2 **
J is corrected as rO, 32tmJ.

(4) r 1.5 in Comparative Example 8 in Table 1 on page 5 of the specification.
J is corrected to r 1.8 J, and ro and 30J are corrected to ro and 40J, respectively.

(5) In Table 2 on page 6 of the specification, "78" in Example 1 is replaced with "84", and "82" in Example 2 is replaced with "84".
"90" and "83" in Example 3 are respectively corrected to "95".

(6) On page 7, line 6 of the specification, the phrase "achieved" is amended to read "achieved and further improved stress relaxation properties."

that's all -237

Claims (1)

[Claims] 1.8-3.0% Ni and 0.15-0.3% by weight
Conductive spring material consisting of 5% Be, 0.2 to 1.2% Si, and the balance Cu and unavoidable impurities