JP2895796B2 - Method for producing high-strength conductive high-chromium-containing copper alloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-strength conductive high-C
The present invention relates to a method for producing an r-containing copper alloy.

[0002]

2. Description of the Related Art FIG. 5 is a photomicrograph showing an ingot of a Cu-15% by weight Cr alloy. As can be seen from FIG. 5, in the ingot material of the Cu-15% by weight Cr alloy, the Cr crystals as the second phase are unevenly distributed. Further, the shape of the Cr crystal is equiaxed. The Cr equiaxed crystal shape is difficult to be formed into a fiber shape even after cold working, and the fiber is unlikely to be a composite material having a uniform distribution. For this reason, high strength was hindered. Therefore, as shown in FIG.
Since the ingot of the alloy is a binary alloy of Cu and Cr,
At the maximum strength, the tensile strength does not reach 1000 MPa.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing, and it is possible to obtain a high-strength conductive high-Cr-containing copper alloy having a tensile strength of 1000 MPa or more and a conductivity of 65% IACS or more. The aim is to provide a method.

[0004]

SUMMARY OF THE INVENTION According to the present invention, Cr is reduced to 10 to 10%.
In a highly conductive copper alloy containing 20% by weight, at least one of C, N, and B is added in an amount of 0.0 to control the crystallization or precipitation characteristics of the Cr phase during solidification and in the solid phase.
Provided is a method for producing a high-strength conductive high-Cr-containing copper alloy, characterized by being added in the range of 1 to 1% by weight.

In the method of the present invention, Sn, Zn, P,
It is preferable to add at least one of Ti and Zr to achieve further higher strength. In addition, at the time of ingot smelting, C, N, and B are added as Cr carbide,
It is preferable to add a powder of Cr nitride or Cr boride.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The high strength conductive high C of the present invention is described below.
The method for producing the r-containing copper alloy will be specifically described.
The C, N, and B elements have not been taken up as an additive element in pure Cu and Cu alloy systems, and further have a scavenging effect of Cr as the second phase (to combine Cr with a third element). Does not exist). In particular, C has the most effective effect, the solubility of the element itself in Cu is extremely low, and there is no influence on the conductivity. The present invention has been made based on the above viewpoint.

The Cu--Cr two-phase alloy shown in FIG. 5 crystallizes Cr, which is a second phase having a low solid solubility in Cu. In the case of a two-phase separated alloy, attention is paid to an increase in strength and electrical characteristics. Then, it is preferable that the Cr crystals of the second phase are uniformly dispersed. Therefore, the present invention provides a technique for controlling the form and distribution of the second phase Cr crystal.

The present invention also provides a technique for controlling the morphology and distribution of the second phase and further increasing the strength by adding a substitutional element. in this case,
In order to improve the yield of the additive in addition to the addition of C, N, and B, a powder of an intermetallic compound with Cr is added as a mother alloy.

The melting point difference between the Cu phase and the Cr phase is large, and there is no means for controlling the Cr crystals in the second phase during solidification. In the present invention, this control is performed using C, N and B elements. is there. Initially, the addition method is also to prepare an intermetallic compound (granular) of these elements and Cr, and to prepare Cu-C
rIn the molten metal, for example, if you try to add C,
As shown in FIG. 1, unmelted residue occurred. Therefore, by using the powder of the intermetallic compound of these elements and Cr, the powder is moderately and uniformly dispersed in the molten Cu and a good cast structure as shown in FIG. 2 can be obtained.

FIG. 3 shows a Cu-15% by weight Cr alloy and Cu
This is a change in thickness due to processing of primary Cr of a -15% by weight Cr-C alloy. As a result, the Cu-15 wt% Cr-C alloy melted by using the present invention tends to have a fiber shape because the Cr crystal is acicularized.

FIG. 4 shows a Cr fiber having a working rate of 99% of a Cu-15% by weight Cr alloy (Comparative Example) and a Cu-15% by weight Cr-C alloy (Example). As is clear from FIG. 4, Cu-15% by weight Cr dissolved by using the present invention is used.
The -C alloy quickly becomes a fiber.

The conductivity and tensile strength of the high Cr-containing copper alloy produced by the method of the present invention and the high Cr-containing copper alloy produced by the conventional method were examined. The results are shown in Table 1 below.

[0013]

[Table 1]

As can be seen from Table 1, the high Cr-containing copper alloy obtained by the method of the present invention has a tensile strength of 1000 MPa.
a or more, and a conductivity of 65% IACS or more was satisfied. This is considered to be because the Cr crystal was acicularized and the Cr crystal was homogenized. On the other hand, the high Cr-containing copper alloy obtained by the conventional method has a tensile strength of 1000M.
Pa or more could not be satisfied.

[0015]

As described above, the method for producing a high-strength conductive high-Cr-containing copper alloy according to the present invention can be applied to a well-conductive copper alloy containing 10 to 20% by weight of Cr, at the time of solidification and in the solid phase. In order to control the crystallization or precipitation characteristics of the Cr phase, at least one of C, N and
Since it is added within the range of 1% by weight, a high Cr-containing copper alloy with high strength can be obtained efficiently at low cost without impairing high conductivity. According to the present invention, C
High strength conductive high C useful for all uses of u-base alloys
An r-containing copper alloy can be provided.

[Brief description of the drawings]

FIG. 1 is a micrograph showing undissolved material in a smelting material due to addition of a Cr—C intermetallic compound (granular).

FIG. 2 shows Cu-15% by weight Cr— produced according to the present invention.
C is a micrograph showing the ingot.

FIG. 3 is a characteristic diagram showing a change in thickness due to processing of a Cr crystal.

FIG. 4 shows a Cr fiber (Cu-1) at a processing rate of 99%.
5 wt% Cr-C and Cu-15 wt% Cr (Comparative Example)
Is a micrograph showing.

FIG. 5 is a micrograph showing a Cu-15 wt% Cr ingot.

──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Nobuo Sakuma 1-2-1 Sengen, Tsukuba City, Ibaraki Prefectural Institute of Science and Technology (72) Inventor Hiroo Suzuki 1-2-1 Sengen, Tsukuba City, Ibaraki Prefecture (72) Inventor: Rio Miyauchi 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd. (56) References JP-A-58-197241 (JP, A) No. 55-12086 (JP, B2) (58) Field surveyed (Int. Cl. ⁶ , DB name) C22C 9/00-9/10 C22C 1/02 503

Claims (3)

(57) [Claims] In a highly conductive copper alloy containing 10 to 20% by weight of Cr, in order to control the crystallization or precipitation characteristics of a Cr phase during solidification and in a solid phase, a small amount of C and N is used. A method for producing a high-strength conductive high-Cr-containing copper alloy, characterized in that at least one kind is added within a range of 0.01 to 1% by weight. 2. The method according to claim 1, wherein at least one of Sn, Zn, P, Ti, and Zr is added to achieve higher strength. 3. The method according to claim 1, wherein a low content of C and N
The method for producing a high-strength conductive high-Cr-containing copper alloy according to any one of claims 1 and 2, wherein at least one powder of Cr carbide and Cr nitride is added as at least one addition method.