JPH067962A - Cu alloy electrode for resistance welding - Google Patents

Abstract

PURPOSE:To provide the Cu alloy electrode for spot welding formed so that the region of the number of continuous dotting can be expanded. CONSTITUTION:The Cu alloy electrodes 3 to 5 contain Dy as an alloy element EA which is non-solutionizable to Cu at 0.01wt.%<=Dy<=1wt.%. The Dy exhibits the effect of hindering the reaction of the Cu which is the essential component of the Cu alloy electrodes 3 to 5 and the Al which is the essential component of the Al alloy members to be welded, thereby preventing the deposition of the Cu alloy electrodes 3 to 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Cu alloy electrode for resistance welding, for example, a Cu alloy electrode used for spot welding between Al-based welded members made of Al or Al alloy.

[0002]

2. Description of the Related Art Conventionally, as a Cu alloy electrode for spot welding an Al-based member to be welded, one made of a Cu--Cr based alloy is known.

[0003]

However, the conventional C
The u alloy electrode has its electric conductivity and thermal conductivity considerably lower than those of Cu itself due to solid solution of Cr with Cu, and is the main component of its main components Cu and Al-based welded members. There is a problem that the Cu alloy electrode is welded to the Al-based member to be welded in the low continuous number-of-spots region because it easily reacts with Al, so that dressing must be performed frequently and the welding work efficiency is poor. It was

In view of the above, it is an object of the present invention to provide the Cu alloy electrode, which has improved welding resistance by improving the material so that the welding work efficiency can be improved.

[0005]

The Cu alloy electrode for resistance welding according to the present invention is insoluble in Cu and is composed of Ba,
It is characterized by containing 0.01% by weight ≦ EA ≦ 1% by weight of at least one alloying element EA selected from Dy, Eu, Gd, Pu, Tb, Sm and Sr, and the balance being Cu.

[0006]

FUNCTION When the alloy element EA is added to Cu, the hardness of the Cu alloy is increased. When a solid-soluble alloy element is added to Cu, the electric conductivity and thermal conductivity of Cu itself are reduced depending on the amount of solid solution, but since the alloy element EA is insoluble in Cu, It is possible to maintain high electric conductivity and the like. Further, the alloy element EA and the reaction product of the EA and Cu segregate mainly at the crystal grain boundaries of Cu crystals and the chemical components of the member to be welded diffuse to the Cu alloy electrode, that is, Cu reacts with the chemical components. Suppress doing. This prevents the Cu alloy electrode from being welded to the member to be welded, even if the member to be welded is, for example, of Al type.

However, if the content of the alloying element EA is EA <
If the content is 0.01% by weight, the above effect cannot be obtained. On the other hand, if EA> 1% by weight, the electric conductivity of the Cu alloy electrode is lowered, so that the temperature rise of the Cu alloy electrode during resistance welding becomes remarkable and the welding is performed. Is likely to occur.

[0008]

EXAMPLES Table 1 shows the composition of OFCu (oxygen-free copper) electrode (1) for spot welding and various Cu alloy electrodes (2) to (7) for spot welding, electric conductivity IACS, and Vickers hardness at room temperature. Hv is shown. Of these Cu alloy electrodes, the Cu component of (2) to (6) is OFCu, and the alloy elements EA include Ba, Dy, Eu, and G.
Dy was used among d, Pu, Tb, Sm and Sr. These alloy elements EA have an effect of suppressing the reaction between Cu and Al because they are insoluble in not only Cu but also Al.

[0009]

[Table 1] OFCu electrode (1) and each Cu alloy electrode (2)
(7) was manufactured by the following method. First, a molten metal having a composition corresponding to each of the electrodes (1) to (7) was prepared by a high-frequency induction heating vacuum melting furnace, and then each molten metal had a diameter of 7 mm.
A billet having a length of 7.4 mm and a length of 100 mm was cast, and then each billet was used to extrude at a temperature of 600 ° C. and an extrusion ratio of about 1
Hot extrusion was performed under the conditions of 5 to obtain a rod-shaped material having a diameter of 20 mm. Then, each rod-shaped material was subjected to machining or the like to manufacture each of the electrodes (1) to (7).

FIG. 1 shows D in each electrode (1) to (6).
1 is a graph showing Table 1 showing the relationship between y content and Vickers hardness Hv. Reference numerals (1) to (6) in the figure correspond to the electrodes (1) to (6), respectively.

FIG. 2 shows D in each of the electrodes (1) to (6).
2 is a graph showing Table 1 showing the relationship between the y content and the electric conductivity IACS. Reference numerals (1) to (6) in the figure correspond to the electrodes (1) to (6), respectively.

From Table 1 and FIGS. 1 and 2, in order to achieve high hardness of the Cu alloy electrode and maintain high electric conductivity, the Dy content is set to 0.01% by weight ≦ Dy ≦ 1% by weight.
It turns out that it should be set to.

Next, spot welding of a plate-shaped Al-based member to be welded having a thickness of 1.2 mm was performed using each of the electrodes (1) to (7). An Al alloy plate made of A5182-O material is used as the Al-based member to be welded, and a welding current is 2100.
The pressure was set to 0 A, the pressure was set to 430 kgf, and the pressurization time was set to 8 cycles.

FIG. 3 shows the number of continuous dots until the electrodes (1) to (7) are welded to the Al-based member to be welded.

As is apparent from FIG. 3, according to the Cu alloy electrodes (3) to (5) having a Dy content of 0.01% by weight ≦ Dy ≦ 1% by weight, the OFCu electrode (1) and other Compared with the Cu alloy electrodes (6) and (7), the continuous dot number region can be expanded, which is due to the above-mentioned various effects such as maintaining high electric conductivity by Dy.

In the above embodiment, the same results as above were obtained when Ba or the like was used instead of Dy.

The Cu alloy electrode according to the present invention is also applied to a Cu alloy electrode for seam welding, and also used for resistance welding of members other than Al-based members to be welded.

[0018]

According to the present invention, by adding a specific amount of a specific alloying element EA to a Cu component, excellent welding resistance can be obtained, and the number of dressings can be reduced to improve welding work efficiency. A Cu alloy electrode can be provided.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the Dy content and Vickers hardness Hv in various electrodes.

FIG. 2 Dy content and electric conductivity IAC in each electrode
It is a graph which shows the relationship with S.

FIG. 3 is a graph showing the relationship between various electrodes and the number of continuous dots until the electrodes cause welding.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takanori Yaha, 1-4-1 Chuo, Wako, Saitama Stock Company Honda R & D Co., Ltd.

Claims (2)

[Claims] 1. A non-solid solution to Cu, which comprises Ba and D
0.01 wt% of at least one alloying element EA selected from y, Eu, Gd, Pu, Tb, Sm and Sr
A Cu alloy electrode for resistance welding, characterized in that ≦ EA ≦ 1 wt% is contained, and the balance is Cu. 2. 0.01% by weight ≦ EA of at least one alloying element EA which is insoluble in Cu and Al and which is insoluble in Cu and is selected from Ba, Dy, Eu, Gd, Pu, Tb, Sm and Sr. A Cu alloy electrode for resistance welding, characterized in that ≤1% by weight is contained, the balance being Cu, and that the Cu alloy electrode is used for resistance welding between Al-based welded members made of one of Al and Al alloy.