JPH02217182A - Method for joining materials of copper or copper alloy - Google Patents

Abstract

PURPOSE:To manufacture a clad material having a sound joint surface at a low cost by putting a side material on a core material on both sides of a Sn- plated layer and heating both materials as they are pressurized without giving plastic deformation. CONSTITUTION:A core material of copper or copper alloy and a side material of copper or copper alloy are joined. Therefore, Sn is plated at least on one of the core material and the side material. The side material is put on the core material on both sides of the plated layer and they are heated as they are pressurized without giving plastic deformation. Consequently, desired mechanical properties can be given respectively to the core material and the side material.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for joining copper or copper alloy materials suitable for producing a cladding material in which the core material and the side materials have mutually different mechanical properties. .

[Prior Art] Conventionally, cladding materials are produced by overlapping a core material and side materials and applying plastic deformation to the core material and side materials by hot or cold rolling, or by crimping the core material and side materials. It is manufactured by crimping (explosion bonding) the wood and side materials using energy from gunpowder fields.

Furthermore, in the crimping method using cold rolling, a method has also been proposed in which a copper-solder clad material is produced by interposing a tin (Sn) plating layer between the steel material and the solder material and cold rolling the material ( JP-A-59-209500). In this method, the tin plating layer suppresses oxidation of lead (PB) in the solder material and improves the soundness of the bonding interface.

``Problems to be Solved by the Invention'' However, in the above-mentioned conventional methods for manufacturing cladding materials, the core material and the side materials undergo plastic deformation.

Therefore, there are problems as shown below.

First, both rolling and explosion bonding require relatively large and complicated equipment. For example, when manufacturing cladding materials by cold rolling, the rolling reduction per pass is generally 30% or more, so an extremely large rolling mill is required to manufacture wide cladding materials. It becomes necessary. Furthermore, when producing a clad material by hot rolling, special measures must be taken to prevent oxidation of the core material or side materials at high temperatures, which is complicated. On the other hand, in the explosive bonding method, in order to explode the gunpowder, the strength of the device must be sufficiently high, and it is necessary to provide an extremely large-scale device.

Next, for example, when producing a clad material by cold rolling metals or alloys with different mechanical properties such as hardness, the behavior of the metal or alloy with lower hardness and the metal or alloy with higher hardness during plastic deformation is Since the cladding ratios are different from each other, it is difficult to control the cladding ratio, and there are also problems in that distortion is likely to occur in the core material or the side materials. For this reason, special consideration is required when manufacturing cladding materials in which the mechanical properties of the core and side materials differ from each other.

Furthermore, in the conventional manufacturing method of cladding materials in which plastic deformation is applied to the core material and the side materials, it is difficult to impart different desired mechanical properties to the core material and the side materials. For example, it is extremely difficult to make the core material hard and the side materials soft. That is, in the cold rolling method, the core material and the side materials undergo plastic deformation at the same time, but due to this plastic deformation, the characteristics of the core material and the side materials become different from their original characteristics. For this reason, generally, after obtaining a clad material by rolling, the clad material is heated and annealed to a predetermined temperature to adjust the hardness. However, in this case as well, if the core material and the side materials have different softening properties, it is extremely difficult to make the core material and the side materials have the desired hardness. Further, similar problems arise when adjusting physical and chemical properties other than hardness.

The present invention has been made in view of such problems, and includes:
The purpose of the present invention is to provide a method for joining copper or copper alloy materials, which allows the mechanical properties of the core material and side materials to be arbitrarily set, and which also allows easy production of cladding materials using simple equipment. shall be.

[Means for Solving the Problems] A method for joining copper or copper alloy materials according to the present invention is a joining method for joining a core material made of copper or a copper alloy and a side material made of copper or a copper alloy. A step of applying Sn plating to at least one surface of the core material and the side material, and a step of overlapping the core material and the side material with this plating layer sandwiched in between and heating while applying pressure within a range that does not cause plastic deformation. It is characterized by having the following.

[Function] In the present invention, a Sn plating layer is disposed between a core material and a side material made of copper or a copper alloy, and the core material and the side material are heated.

Then, Cu in the core material and the side material diffuses into the Sn plating layer, and the core material and the side material are joined by a type of diffusion bonding that utilizes high-speed diffusion of Cu atoms inside the Sn plating layer. In this case, pressure is applied to the extent that the core material and the side materials are brought into close contact with each other, but such pressure that the core material and the side materials undergo plastic deformation is not applied. Therefore, in this joining process, the mechanical properties of the core material and the side materials do not substantially change, so that the core material and the side materials that finally have the required properties can be subjected to the joining process. In other words, a clad material with predetermined characteristics can be manufactured by joining a core material and side materials that have the characteristics required for a clad material product, so a clad material with arbitrary mechanical properties can be manufactured. can be easily manufactured.

Next, the reason why the plating layer is limited to Sn will be explained.

A method of bonding metals together by diffusion of metal atoms is a well-known technique, but in order to use this technique industrially, bonding by diffusion must be performed within an economically possible time.

In general, the main mechanisms by which atoms diffuse in metals are a vacancy diffusion mechanism in which diffusion progresses through atomic vacancies, and an interstitial diffusion mechanism in which atoms move through gaps between atoms. In this case, the rate of atomic diffusion is faster in the latter interstitial diffusion mechanism. However, the diffusion of metal atoms such as Au, AgCu, and Zn in Sn differs from these mechanisms; the metal atoms are located between crystal lattices and form pairs with Sn atoms, which may reorient or separate. S of
Diplons diffuse while recrystallizing with n atoms.
on) Controlled by the mechanism (Hideo Chubu, Journal of the Japan Institute of Metals)
Vol. 22, No. 6, pp. 480-487).

Due to this diplon mechanism, the metal atoms diffuse into Sn at an extremely high rate. The present invention utilizes this diplon mechanism industrially.

Incidentally, in addition to Sn, there is PB as a plating metal in which Cu atoms diffuse by this diplon mechanism. but,
Since PB causes hot deoxidization of copper alloys, alloys containing PB cannot be reused as scrap, and for this reason, it is not industrially preferable to use a PB plating layer. Therefore, in the present invention, Sn
The plating layer is used for joining copper or copper alloy materials.

[Example] Next, an example of the present invention will be described. In this example,
A cladding material is manufactured by joining a copper or copper alloy side material to a copper or copper alloy core material.

First, apply Sn plating to the core material or side materials. This Sn plating may be applied to both the joint surfaces of the core material and the side materials, or it may be applied only to either joint surface, and the surface to be Sn plated may be one or both sides of the core material or the side materials. Either of these is fine. Furthermore, the Sn plating may be a bright plating or a matte plating, and the effect is the same.

The thickness of the Sn plating layer is not particularly limited in view of the bonding effect, but if the Sn plating layer is too thick, the heating time required in the process described below will be longer, and the manufacturing cost will increase.

On the other hand, if the thickness of the plating layer is too thin, uneven plating will occur. For these reasons, the thickness of the Sn plating layer is 0.
．． The thickness is preferably 3 to 10 μm.

Next, the core material and the side materials are overlapped with the Sn plating layer interposed therebetween, and heated while applying pressure to an extent that the core material and the side materials do not undergo plastic deformation. This pressurization is performed in order to bring the core material and the side material into close contact with each other, to ensure sufficient diffusion of Cu atoms by the above-mentioned diplon mechanism, and to firmly bond the core material and the side material. Therefore, it is necessary to avoid applying excessive pressure to the extent that the core material or the side materials undergo plastic deformation, since this will change the mechanical properties of the core material or the side materials. If the contact between the core material and side material is maintained sufficiently, the pressing force at this time should be approximately Okg/cr.
Even if it is d, the core material and side materials can be sufficiently made into crat. However, in order to obtain a more sound rudd material, it is preferable to apply pressure at a pressure in the range of 10 to 80% of the yield strength of the core material or side material.

The heating temperature at this time does not need to be particularly high because, for example, the diffusion coefficient of Cu atoms in Sn at a temperature of 23° C. is approximately 4×10 −9 , which is sufficiently large and the Cu diffusion rate is fast. On the other hand, if the heating temperature is too high, the surfaces of the core material and side materials may be oxidized or their properties may change, so the heating temperature is preferably 300° C. or lower.

Note that the plating process and the heat-pressing process can be performed continuously, but they may also be performed separately. Further, in the heat-press bonding step, pressure may be continuously applied to the core material and side materials using a pair of rolls, or pressure may be applied to the entire surface of the core material and side materials in a batch method.

Next, the results of actually manufacturing a clad material using the method of this example will be explained.

Thickness 11LL For core material, thickness 0.8mm, Vickers hardness 1
Prepare 80mm phosphor bronze plate material and use it as side material with a thickness of 0.
．． A phosphorus-deoxidized copper plate material having a diameter of 4 mm and a Vickers hardness of 10 mm was prepared, and a square core material and side material each having a side of 200 mm were cut out from each plate material. Next, one side of the side material was masked, and the other side was coated with matte Sn plating with a thickness of 1.0 μm. The plating conditions at this time are shown below.

Plating solution; S n S 04 40g
/ (IH2804100g/j'cresol)onic acid 30g71 Dispersant
10g/Jl current density; 2.5A/dm
2 Liquid temperature: 20°C Next, this side material was stacked on the core material with the plated surface inside, and this was placed in a pot press device heated to 150'C, and a pressure of 5kg/crd was applied to 30°C. Hold for minutes. As a result, Cu atoms in the core material and side materials become Sn
It diffused into the plating layer, and the core material and side materials were joined to produce a cladding material.

The clad material was then taken out of the hot press and cooled.

The following tests were conducted on the cladding materials of phosphor bronze and phosphorus deoxidized copper produced as described above.

■A small piece was cut out from this crud material and its cross section was observed using an optical microscope. Figure 1 is a photograph of the metallographic structure of this cross section (
(1000x magnification).

As is clear from FIG. 1, there were no defects such as cavities at the boundary between the core material and the side materials, and the two were soundly joined.

■The Vickers hardness of the core material and side materials was measured.

As a result, the Vickers hardness of the core material was 180, and the Vickers hardness of the side materials was 99. The Vickers hardness of the core material was the same as before joining, and the Vickers hardness of the side materials was also almost the same as before joining. It is.

■This clad material was heated at 400°C for 5 minutes to test the soundness of the joint.

As a result, no problems such as blistering or peeling occurred.

As described above, in this example, the core material and the side materials were not plastically deformed, and a cladding material having an extremely sound joint surface could be manufactured without substantially changing its mechanical properties.

Example 2 A brass plate coil with a width of 250 mm, a thickness of 0.6 mm, and a Vickers hardness of 80 was prepared for the core material, and a coil of a brass plate with a width of 250 mm, a thickness of 0.2 mm, and a Vickers hardness of 80 was prepared for the side material. A coil made of an oxygen-free copper plate having a hardness of 60 was prepared. Then, one side of the side material unwound from the oxygen-free copper plate coil is coated with 0.0% bright Sn plating.
It was applied to a thickness of 5 μm. Next, this side material and a core material unwound from a coil of brass plate were overlapped with the plated surface sandwiched therebetween, and this was passed through a hot laminator having silicone rubber rolls heated to 250°C. At this time, the pressing force of the roll was 5 kg/crd, and the sheet passing speed was 2 m/min.

A test piece of a predetermined size was cut from the cladding material obtained as described above, and its cross section was observed with an optical microscope to examine the state of the bond between the core material and the side material.

In addition, as in the first example, the Vickers hardness and the presence or absence of blistering and peeling after heating were examined. As a result, the Vickers hardness of the core material and side materials was the same as before joining, and the core material and side materials were joined extremely soundly.

Furthermore, the following tests were conducted on test pieces of this clad material.

(2) A test piece with a width of 10 and a length of 80 mm was bent at an angle of 90° with a bending radius of 0.9 mm, the bent portion was cut, and the cross section was observed using a microscope.

As a result, no peeling between the core material and the side materials at the joint was observed.

(2) A disk with a diameter of 60+++n was punched out using a punch and die, and the cross section of its peripheral edge was observed using a magnifying glass.

As a result, no peeling between the core material and the side materials was observed at the joint portion.

The disk punched in step 2 was deep drawn using a punch with a diameter of 3311II11 to form it into a cylindrical shape. This cylinder was cut in the axial direction, and the cross section was observed with a magnifying glass. As a result, no peeling between the core material and the side materials at the joint was observed.

As mentioned above, in the cladding material manufactured by the method of this embodiment, the core material and the side material are joined extremely soundly, and various molding processes are possible.

It is clear that the method of the present invention can be used not only for producing cladding materials but also for joining copper or copper alloys of any shape.

[Effects of the Invention] As explained above, according to the method of the present invention, Sn is added to at least one of the core material and the side material of copper or copper alloy.
Since the core material and the side materials are plated, and then the core material and the side materials are overlapped and heat-bonded via the plated surfaces, the cladding material can be manufactured without plastically deforming the core material and the side materials. This makes it possible to manufacture cladding materials at low cost, in which the core material and side materials each have the desired mechanical properties and have an extremely sound joint surface, without requiring complicated, large, and expensive equipment. can.

[Brief explanation of the drawing]

FIG. 1 is a metallurgical microscope photograph showing a cross section of a Clarad material manufactured according to an example of the present invention. Written amendment (method) 1. Indication of the case Patent Application No. 36937, 1999 2. Name of the invention Method for joining copper or copper alloy materials 3. Person making the amendment Relationship to the case Patent applicant address Kobe City, Hyogo Prefecture 1-3-18 Wakihamacho, Chuo-ku Name (119) Kobe Steel Co., Ltd. Representative: Sokichi Kametaka 4, Agent address: 4th floor, Isoyama Building 2, 2-3-29 Hamamatsucho, Minato-ku, Tokyo 105) 6. Column for brief explanation of drawings subject to amendment and drawings in specification 7゜Contents of amendment (1) Drawings will be deleted. (2) Delete the column "4. Brief description of the drawings" from page 14, line 19 to page 15, line 1 of the specification. that's all

Claims (1)

[Claims] (1) In a joining method for joining a core material made of copper or a copper alloy and a side material made of copper or a copper alloy, the step of applying Sn plating to at least one surface of the core material and the side material; A method for joining copper or copper alloy materials, comprising the step of overlapping the core material and the side materials with the plating layer sandwiched therebetween, and heating while applying pressure within a range that does not cause plastic deformation.