JPS60227998A - Electrode material for welding - Google Patents

Abstract

PURPOSE:To produce easily an electrode material for welding having excellent conductivity of electricity and heat without abnormal generation of heat during use by providing a specific coating layer dispersed with oxide, carbide, etc. on the surface of a copper alloy. CONSTITUTION:The dispersion type alloy coating layer 4 is provided on the surface at the tip 3 of the copper alloy 1. The dispersion type alloy is made by using a metal or alloy, for example, Co, Cr, W, Mo, Ni, Ti, etc. or the alloy thereof, etc. as a base and dispersing particles of oxide, carbide, nitride or carbonitride, for example, chromium carbide, tungstan carbide, titanium carbide, etc. therein. A method such as electroplating, electroless plating or vapor deposition method is used to form the dispersion type alloy coating layer.

Description

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

(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. -Cr alloy, Cu-Cr-Zr alloy, Cu
-Be-Go gold alloys 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 characteristics required for welding electrode materials used in spot welding, soma welding, etc., and electric brazing welding are as follows.

■Good electrical and thermal conductivity: As mentioned above, it is necessary to pass a large current through the electrodes, so there is no need to generate much heat due to electrical resistance, and the generated heat needs to be quickly conducted and cooled. be.

■Deformation resistance In Ni-spot welding, strong compressive stress is applied to the electrode tip during welding, so mechanical strength is required at high temperatures of 500°C or higher as well as at room temperature.

If the tip of the electrode is deformed or cracked, it is difficult to apply sufficient stress uniformly to the welded part, which adversely affects the welding strength and the appearance of the welded part.

■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 tip of the electrode, but welding will interfere with welding. , 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.

Gold, Cu-Be-Co alloys, etc. have the following inadequacies in light of the above-mentioned necessary properties.

In other words, Cu-Cr alloy and Cu-Cr-Zr alloy have high electrical conductivity and are excellent in terms of softening resistance and hardness at high temperatures, but they must be hardened at a high temperature of approximately 1000'C during manufacturing. In this case, the crystal grains may become coarse and the deformation resistance may not be excellent, and these alloys tend to crack at the tip when used as electrodes, and the inventors believe that this is because the Cr It was found that this is facilitated by the presence of

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.

Other materials such as VI'+ Mo, which have even higher high-temperature strength, can be considered, but other requirements for electrodes, such as high electrical conductivity, may be impaired, and the electrode itself may generate abnormal heat due to its resistivity, or its toughness may deteriorate. It was difficult to put it into practical use because of cracks and damage caused by the drop.

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
No. 4187fi) has been proposed, but since the electrical conductivity of the surface layer is low and the heat generation at the tip is large, the copper alloy that is the base material often softens, deforms, and melts, and the service life is insufficient. There wasn't.

(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,
A metal or alloy in which carbonitrides or carbonitrides are dispersed to provide a welding electrode material that generates less excess heat at the tip of the electrode, has less wear on the electrode, and is easily manufactured. This is a welding electrode material characterized by being provided with a coating layer consisting of.

Hereinafter, the present invention will be explained by examples using the drawings.

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

Reference numeral 4 denotes a coating layer (hereinafter referred to as a dispersed alloy coating layer) made of a metal or alloy in which oxide, carbide, nitride, or carbonitride is dispersed and coated on the outermost surface.

In FIG. 1, a dispersed alloy coating layer 4 is provided on the surface of a tip 3 of a copper alloy 1.

In FIG. 2, a copper coating layer 5 is applied over the entire surface of the copper alloy 1 by electroplating, and a dispersed alloy coating layer 4 is further applied thereon.

In Fig. 3, a dispersed alloy coating layer 4' is applied to the entire surface of the copper alloy 1, and a dispersed alloy coating layer 4# different from the lower layer is formed on the surface of the tip 3, and another dispersed alloy coating layer 4#, which is different from the lower layer, is formed on the surface of the tip 3. It has a layered finish.

In Figure 4, the copper alloy 2 in the center of the chip body 1' is shown. A dispersion type alloy coating layer is provided on the surface of the plate.

The tip shown in FIG. 5 is a tip for spot welding, in which a dispersed alloy coating layer 4 is provided on the surface of the tip 3 of a copper alloy 1.

In the present invention, the copper alloy serving as the base material is a dispersion-strengthened steel alloy based on copper and added with Cr+ZrlBelCo1Mo.

Further, the dispersed alloy constituting the surface coating layer is a metal or an alloy, such as Go, Cr+ wl Mo+ Ni+ Ti
etc. or their alloys, etc., with oxides,
Carbides, nitrides or carbonitrides, such as chromium carbide, tungsten carbide, titanium carbide, silicon carbide, aluminum oxide,
It is a material in which particles of titanium nitride, tantalum nitride, titanium carbonitride, etc. are dispersed, and the particle size g O is preferably 1 to 2 μm.

Even when the base metal or alloy disappears during welding or soldering, the dispersed alloy coating layer still has dispersed oxide, carbide, nitride, or carbonitride particles that remain and accumulate tightly on the surface. The thickness of the coating is preferably 5 to 100 microns. If it is less than 5μ, the effect of preventing welding will be small, and if it exceeds 100μ, it will be industrially expensive and the electrode tip will generate a lot of heat.

Methods such as electroplating, electroless plating, and vapor deposition are used to coat the dispersed alloy coating layer. For example, N.L.C.
Electroplating is performed by dispersing particles of the dispersion compound in a plating solution such as O or Cr.

Also, this coating layer may be only one layer as shown in Figure 1.2.4.5, or it may be multiple layers of two or more dispersed alloy coating layers of different materials as shown in Figure 3. It's good as well.

Further, in order to improve the adhesion with the copper alloy, a copper coating layer 5 may be provided in the middle by electroplating as shown in FIG.

(Example) A welding electrode tip body as shown in Figure 1 was made from the base metal alloy shown in Table 1, and N115 was activated on the tip surface of the dispersion type alloy under various conditions as shown in Table 1. The coatings were applied by reactive vapor deposition, others by electroplating.

The dimensions of the electrode were 16 m++ in diameter in the parallel part and 8+1++ in diameter at the tip.

The obtained electrode tip was used for spot welding to a thickness of 0.8
Two galvanized iron plates of the fin were overlapped and spot welded using the same upper and lower electrodes under the conditions of 10kA of current, 200kg of pressure, and 25 cycles of welding time, and the number of welds until welding occurred on the electrodes was measured.The results are shown in the table below. As shown in 1.

Table 1 From Table 1, N11l~6 according to the present invention is N1 of the conventional example.
It can be seen that, compared to No. 17, all of them have a much longer lifespan until welding occurs.

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

(0) Since a coating layer made of a metal or alloy in which oxides, carbides, nitrides, or carbonitrides are dispersed is provided on the surface of the copper alloy, the metal or alloy in the dispersed alloy of the coating layer is used when welding or soldering. Even if the dispersion compound particles disappear, the dispersed compound particles remain and accumulate well on the surface, and since the dispersed alloy has good oxidation resistance, it is difficult to fuse. In particular, it is difficult to weld to welded materials coated with low melting point metals or alloys such as Zn, Sn+solder, and Ag.

(c) Since the coating layer is thin and is mainly made of metal or alloy, there is little excess heat generation at the electrode tip.

Also, since the coating layer is a dispersion-strengthened alloy, there is less wear.

(:) It has a simple structure and can be easily manufactured by electroplating, for example, on a copper alloy with a plating solution in which dispersed compound particles are dispersed.

[Brief explanation of the drawing]

FIG. 1.2...Copper alloy, 1'...Chip body, 3...
Tip, 4.4', 4'... Dispersed alloy coating layer, 5...
・Copper coating layer.

Claims (1)

[Scope of Claims] (+) A welding electrode material characterized in that a coating layer made of a metal or alloy in which oxide, carbide, nitride, or carbonitride is dispersed is provided on the surface of a copper alloy. (2) The welding electrode material according to claim 1, wherein the coating layer has a thickness of 5 to 100 μm. (3) The metal or alloy constituting the coating layer is Go+Cr
+The welding electrode material according to claim 1 or 2, which is Mo or Wl or an alloy thereof. (4) The carbide constituting the coating layer is Cr + W + M
The welding electrode material according to claim 1, 2 or 3, which is a carbide of o + Ta or TI.