JPS6059979B2 - High strength, high conductivity copper alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to a high strength, high conductivity copper alloy having strength comparable to brass, but with much greater electrical conductivity and stress corrosion cracking susceptibility.

Brass is an alloy of copper with an appropriate amount of zinc added, and because it contains a large amount of inexpensive zinc, it is low in cost and has excellent strength, so it is widely used in wiring equipment, electrical and electronic parts, etc. There is. However, this alloy has the disadvantage of low electrical conductivity and is susceptible to stress corrosion cracking. Recent developments in the electrical and electronic industries have been remarkable, and as a result, improvements in the reliability of these devices have been desired, and component materials have also become more conductive.
There is a need for alloys that have high strength, are easy to manufacture, and are inexpensive.

In view of this, as a result of various studies, the present invention has developed a high-strength, high-conductivity copper alloy that has strength equivalent to that of brass, superior conductivity, and stress corrosion cracking susceptibility.
．． 1-2.0% and P0.01-0.5%, Ag, Sn
, In, Mg, Mn, Zn, Si, Al.
It is characterized by containing one or more species in a total amount of 0.1 to 1.0%, with the remainder being Cu. That is, the present invention improves the strength without significantly reducing the electrical conductivity by adding Co to Cu, and adds P to this to improve the strength of Co and P.
By coexisting with P(5Co), an intermetallic compound of P(5Co) is formed, and the precipitation of the compound is promoted to improve the electrical conductivity, and a healthy ingot is obtained due to the deoxidizing effect of P. Furthermore, Ag, Sn, In, Mg, Mn, Zn
By adding one or more of , Si, and Al, the strength is further improved without significantly lowering the electrical conductivity.

The reason for limiting the Co content to 0.1 to 2.0% is that if it is less than 0.1%, the improvement in strength is insufficient;
This is because if the P content exceeds 0%, the strength improvement effect will be saturated and the workability will decrease.
The reason for limiting the percentage is that if it is less than 0.01%, the amount of intermetallic compound of Co and P will be small, and the effect of promoting the precipitation of this compound will be insufficient, making it impossible to expect an improvement in electrical conductivity. This is because Cu does not combine with Co, but forms a solid solution in Cu, lowering the electrical conductivity.

In addition, the total content of one or more of hSn91n, Mg, Mn9Zn, Si, and Al is 0.1 to 1.
．． Limited to 0%. The reason for this is that if it is less than 0.1%, the effect on improving strength is insufficient, and if it exceeds 1.0%, the electrical conductivity will be significantly lowered and workability will be impaired. Next, examples of the alloy of the present invention will be explained. Using a graphite crucible in a high-frequency melting furnace, Cu is melted while covered with charcoal, and after melting, qo is added with CU-50% Co master alloy, and then P is added with CU-15% P debt. Finally, one or more of Ag, Sn, In, Mg, Mn, Zn, Al, and Si are added, and this is cast into a mold to obtain an ingot (with the composition shown in Table 1). (thickness 30T! Rltl width 10i1 length 200?) was obtained. Next, both sides of each of these ingots were faceted to a thickness of 2.5 m, and then heated to a thickness of 1 m at 900°C.
It was hot rolled to 0TfrI1& then cooled to room temperature. Although it is preferable that this cooling be done quickly, it is not always necessary to carry out underwater cooling. Next, this plate was repeatedly subjected to cold rolling and intermediate annealing to produce a plate with a thickness of 0.5 mm. The final degree of cold working was 30%. Next, various test pieces were cut out from the obtained plates and examined for electrical conductivity, tensile strength, and stress corrosion cracking susceptibility.

The results are shown in Table 2. Susceptibility to stress corrosion cracking was determined by cutting a sample 10 m wide and 10 mm long from a plate (thickness 0.5 wn), bending it by 180 degrees with a bending radius of 4 m, and leaving it in an ammonia gas atmosphere until it broke. The time taken was measured.

As is clear from Tables 1 and 2, the present invention. alloy(
No. l~NOl8) all have a tensile strength of 48~53kg
/i, conductivity 63-78% IACSl rupture days 1
0 days or more, all of which are conventional alloys (NO24) 651
It can be seen that it has similar tensile strength, superior electrical conductivity, and stress corrosion cracking susceptibility compared to No. 35 brass.

On the other hand, as is clear from the comparative alloys (NO.19 to NO.23), alloys with low CO content (NO.19 to NO.23)
) has poor tensile strength and insufficient stress corrosion cracking resistance.

Also, alloy NO. with low P content. 2O and rich alloys (N
O23) all have insufficient electrical conductivity. Also Ag,S
The alloy (NO.2l) to which none of n, In, Mg, Zn, Mn, Si, or Al is added has poor tensile strength, and Ag,
The alloy (No. 22) containing a large amount of Sn, N, Mg, Zn, Mn, Si, or Al has insufficient electrical conductivity. It should be noted that the alloy with a large amount of CO added had poor workability and was not practical, so the test was omitted.

In this way, the alloy of the present invention has strength equivalent to that of brass, excellent electrical conductivity, and stress corrosion cracking susceptibility, and can be used in parts of electrical and electronic equipment to improve their reliability. be effective.

Claims (1)

[Claims] 1 Co0.1-2.0% and P0.01-0.5%, and any one or more of Ag, Sn, In, Mg, Mn, Zn, Si, Al, total 0.1 A high-strength, high-conductivity copper alloy consisting of ~1.0% Cu and the balance Cu.