JPS60231596A - Material of electrode for welding - Google Patents

Abstract

PURPOSE:To obtain a titled material cheap and easy to manufacture and high in conductivity of electricity and heat by making an intermediate covering layer and the same metal a base on copper alloy, and providing a surface covering layer in which oxides, carbides, nitrides or carbonitrides are diffused. CONSTITUTION:An intermediate covering layer made of metal or alloy is provided on a base metal of copper alloy made by adding metals such as Cr, Zr etc. or dispersing oxides such as Al2O3 etc. in the base of copper, and a surface covering layer of diffusion type alloy made by diffusing oxides, carbides, nitrides or carbonitrides in the base of metals or alloys same as those constituting above- mentioned intermediate covering layer is provided on the intermediate covering layer, and a material of electrode for welding having high conductivity of electricity and heat, difficultly deposited and deformed, small in wear, and does not cause excessive heat generation at the tip of the electrode is obtained. Proper thickness of above-mentioned intermediate and surface covering layers is 0.5- 100mu and 5-100mu respectively, and Co, Cr, W, Mo are used suitably for the base of above-mentioned diffusion type alloy, and carbides of Cr, W, Ti, Ta are used suitably as carbides.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a welding electrode material, and particularly to a welding electrode material for welding and soldering.

(Background technology) In recent years, highly productive spot welding has come into widespread use, for example, for joining mild steel sheets and galvanized steel sheets in the automobile industry. Cu-Cr alloy, Cu-Cr-Zr alloy, CL
l-Be-Co alloys and the like have been used.

Such welding electrodes require large currents during welding,
Moreover, since it is used continuously, it becomes hot and there is a problem that the tip part is easily cracked, deformed, or worn out.

Therefore, the general properties required for welding electrode materials used in welding such as spot welding and beam welding, and electric soldering are as follows.

■Good electrical and thermal conductivity: As mentioned above, a large current needs to flow through the electrodes, so it needs to be guided and cooled by electrical resistance.

■Deformation resistance In Nispot welding, strong compressive stress is applied to the electrode tip during welding.
A and mechanical strength at room temperature are required.

If the tip of the electrode is deformed or cracked or cracked, sufficient stress will not be applied uniformly to the welding part.
It also has a negative impact on the bonding strength and the appearance of the welded area! I can do it.

■Do not weld: If the electrode material and the material to be welded, the solder material, etc. are likely to form an alloy, the material to be welded, the solder material, etc. will easily weld to the electrode tip y1, but welding will interfere with welding. Therefore, it is desirable that there be no welding.

■ Ease of manufacturing and price: It is desired that the alloy itself be easy to manufacture, have excellent processability into welding electrodes, and be low-priced as a consumable item.

Conventionally used Cu-Cr alloys, Cu-Cr-Zr alloys, and Cu-Be-Go gold alloys have the following inadequacies in light of the above-mentioned necessary properties.

In other words, Cu-Cr alloys and Cu-Cr-Zr alloys have high conductivity and are excellent in terms of softening resistance and hardness at high temperatures, but they must be sintered at a high l crystalline temperature of about 1000°C during manufacturing. The present inventors believe that the cause of this problem is that the crystal grains may become coarse and have poor deformation resistance due to the heating process, and that these alloys tend to crack at the tip when used as electrodes. It has been found that this is promoted by the presence of Cr.

Although Cu-Be-Co alloy has high strength at room temperature, it has low electrical and thermal conductivity, easily generates heat during use, and has poor softening resistance, making it a desirable material for electrodes despite its high price. It wasn't.

In addition, W and Mo Nakichi, which have even higher high-temperature strength, can be considered, but other requirements for electrodes, that is, high electrical conductivity, are impaired, and the electrode itself constantly generates heat due to its own resistance. However, it was difficult to put it into practical use due to cracking and breakage due to decreased toughness.

In addition, a welding electrode having a coating layer of nitride, carbide, or carbonitride on the surface of a copper alloy in which oxides are dispersed (Japanese Patent Laid-Open No. 58-1
4187G) has been proposed, because the electrical conductivity of the surface layer is low and the heat generation at the tip is large, L+J
The copper alloy that makes up the shrine was susceptible to softening, deformation, and melting, and its lifespan was not long enough.

(Disclosure of the Invention) The present invention has been made to solve the above-mentioned problems, and has excellent electrical and thermal conductivity, and when used as a welding electrode,
It is an object of the present invention to provide a welding electrode material that generates less excess heat at the tip of the electrode during welding, has less wear on the electrode, does not separate the area of the surface coating layer, and is easy to manufacture.

The present invention provides an intermediate coating layer consisting of a metal or an alloy, and an oxide, carbide, nitride, or carbonitride of the copper alloy. or a welding electrode material characterized by being provided with a surface coating layer made of a dispersed alloy based on the same metal or alloy as the alloy.

In the present invention, the copper alloy serving as the base material is made of copper, and then Cr+ Zr, Be-+ Cot M
Alloys to which metals such as o are added (e.g., Cl-Cr+ Cu-
Cr-Zr+Cu-Be-Co, Cu-Zr-Fe-
P alloy, etc.), AQ203, etc.

Further, the metal or alloy (hereinafter abbreviated as metal) constituting the intermediate coating layer is, for example, Cot Cr, W, Mo, etc., or alloys thereof.

Further, the dispersion type alloy constituting the surface coating layer is based on the same metal as the metal mentioned above constituting the intermediate coating layer, and contains oxides, carbides, nitrides, or carbonitrides, such as chromium carbide and tungsten carbide. , titanium carbide, silicon carbide, aluminum oxide, titanium nitride.

It is made by dispersing particles of tantalum nitride, titanium carbonitride, etc.

In this surface coating layer, even if the base metal of the dispersion type alloy disappears during welding or soldering, dispersed oxide, carbide, nitride, or carbonitride particles remain and accumulate well on the surface. Therefore, the coating layer is preferably 5 to 100 microns. If it is less than 5μ, there is little welding prevention effect, and 1007
If it exceeds z, the T-intensive cost will increase, and the heat generated at the tip of the electrode will become a problem.

Further, the intermediate coating layer is provided to provide a backup effect that can withstand the use of the base copper alloy and the surface coating layer. 11f is the same metal as the base of the dispersion type alloy on the surface, which is preferable because a series of effects are further increased. The coating thickness is preferably from 0.5 to 100 microns; if it is less than 0.5 microns, the effect of improving adhesion will be small, and if it exceeds 100 microns, industrial costs will increase.

Incidentally, the tendency of the copper alloy of the base material and the intermediate coating layer to fall off is 1-. Therefore, a base layer of Cu, Ni, etc. may be provided.

Hereinafter, the present invention will be explained with reference to the drawings and examples.

1 to 5 are longitudinal cross-sectional views showing electrode tips according to embodiments of the present invention. In the figure, 1 is a copper alloy constituting the chip body, 3 is the tip of the electrode, and 1' shown in Figure 4 is the chip body, with a copper alloy 2 (e.g. carbon fiber (reinforced copper alloy, etc.) or bonded.

4 is an intermediate coating layer made of the metal or alloy as described above; 5
is a surface coating layer made of a dispersed alloy as described above.

In FIG. 1, the tip 3 of the copper alloy 1 is coated with an intermediate coating layer 4 and a surface coating layer 5.

In FIG. 2, the entire surface of the copper alloy 1 is coated with an intermediate coating layer 4 and a surface coating layer 5.

In FIG. 3, the entire surface of the copper alloy 1 is coated with an intermediate coating layer 4', and the surface of the tip 3 is coated with the intermediate coating layer 4 and the surface coating layer 5. In this case, the intermediate coatings 4 and 4' may be made of the same or different metals.

In FIG. 4, the surface of the copper alloy 2 at the center of the chip 1' is coated with an intermediate coating layer 4 and a surface coating layer 5.

The tip shown in FIG. 5 is a tip 3 of a copper alloy 1 coated with an intermediate coating layer 4 and a surface coating layer 5, and is a tip for spot welding.

To coat the dispersion alloy of the surface coating layer, electroplating,
Methods such as electroless plating and steaming 4'J method are used. For example, electroplating is performed by dispersing particles of a dispersed compound in a plating solution such as Ni, Co, or Cr.

(Example) A welding electrode tip body as shown in FIG. 1 was prepared from the base metal alloy shown in Table 1, and the intermediate coating layer 4 and The surface coating layer 5 was coated under various conditions. The coating method is electroplating (A), 7!
I! Electrolytic plating (B) and activated reaction vaporization (C) were used.

The dimensions of the electrode were a parallel part diameter of 1 [imm] and a tip part diameter of g mm.

The obtained electrode tip was used for spot welding to a thickness of 0.8
Two mm galvanized iron plates were stacked together, and the lower electrode was used as the same electrode, current 10 kA, pressure 2oo++g, welding time 25
Table 1 shows the results of spot welding under cycle conditions and determining the number of dots until welding occurs on the electrode as 1 jill.

From Table 1, NαI to G according to the present invention have extremely long lifespans until welding occurs, compared to the comparative example and the conventional example.
It can be seen that @11 separation does not occur. N without intermediate coating layer
α7 and Nα8, in which the metal of the intermediate coating layer and the base of the surface coating layer were different, caused gl+ separation.

Table 1 (Effects of the Invention) The welding electrode feed of the present invention configured as described above has the following effects.

(a) Since the electrode body is made of copper alloy, it has excellent electrical and thermal conductivity, and there is little abnormal heat generation during welding or forge welding.

(D) Since the outermost surface is provided with a surface coating layer made of a dispersed alloy in which a metal or an alloy is dispersed with a metal or an alloy, a metal or a carbonitride is dispersed in the dispersed alloy during welding or brazing. Even if the alloy disappears, the dispersed compound particles remain and accumulate well on the surface, and since the dispersed alloy has good oxidation resistance, it is difficult to weld and life is improved. Especially Zn,
It is also difficult to weld to welded materials coated with low melting point metals or alloys such as Sn, Ag, etc.

, f% Also, since there is a bone dispersion type alloy, there is less wear.

(c) Since an intermediate coating layer made of the same metal or alloy as the base of the dispersed alloy of the surface coating layer is provided on the copper alloy, the adhesion between the copper alloy and the surface coating layer is good and peeling does not occur.
Even if the surface coating layer disappears, the intermediate coating layer can withstand use.

(d) All the coating layers are thin and are mainly made of metal or alloy, so there is no excess heat generation at the tip of the electrode.

(e) The structure is simple, and the surface coating layer can be easily manufactured by electroplating using a plating solution in which dispersed compound particles are dispersed, so that it is easy to manufacture.

[Brief explanation of the drawing]

FIGS. 1 to 5 are longitudinal cross-sectional views showing electrode tips according to embodiments of the present invention. 1.2...Copper alloy, 1'...Chip body, 3...
Tip, 4.4゛... Intermediate coating layer, 5... Surface coating layer. Meeting 1 3M Fountain 51-) Station 2 Ticket 4

Claims (1)

[Claims] The intermediate coating layer comprises an intermediate coating layer made of a metal or alloy, and an oxide, carbide, nitride, or carbonitride dispersed thereon in a (+) copper alloy. A welding electrode material comprising a surface coating layer made of a dispersed alloy based on the same metal or alloy as that of the welding electrode material. (2) The intermediate coating layer has a thickness of O5-100μ,
The welding electrode material according to claim 1, wherein the surface coating layer has a thickness of 5 to 100 microns. (3) The welding electrode material according to claim 1 or 2, wherein the dispersed alloy is based on Co, Crlw, Mo, or an alloy thereof. (4) The welding electrode material according to claim 1, 2, or 3, which is a carbide or a carbide of Cr, W, Ti, or Ta.