Electrode materials commonly used in spot welders

Update:07 Sep 2020

Chromium Zirconium Copper (CuCrZr) Chromium Zirconium C […]

Chromium Zirconium Copper (CuCrZr)

Chromium Zirconium Copper (CuCrZr) is the most commonly used resistance welding electrode material, which is determined by its own excellent chemical and physical properties and good cost performance.
The chromium-zirconium-copper electrode achieves a good balance of the four performance indicators of the welding electrode:
Excellent conductivity----------guarantee the minimum impedance of the welding circuit and obtain excellent welding quality
High temperature mechanical properties----------Higher softening temperature ensures the performance and life of electrode materials in high temperature welding environment
Abrasion resistance----------Electrode is not easy to wear, prolong life and reduce cost
Higher hardness and strength----ensure that the electrode tip is not easily deformed and crushed under certain pressure, and the welding quality is guaranteed.
1) The chemical composition analysis of the alloy is in accordance with the provisions of ZBH62-003.1-H62003.8;
2) The hardness of the alloy is measured according to GB230, and the average value of three points is measured for each sample;
3) Eddy current conductivity meter (eddy current comparison method) for conductivity measurement. Three points are measured for each sample, and the average value is used. For samples with a diameter of less than 15mm, the measurement can be carried out according to the provisions of GB3048.2;
4) For the softening temperature test, place the sample in a furnace that is heated to 550°C (after closing the furnace door, it is required to return to this temperature within 15 minutes and hold for 2 hours, then quench it with water, and measure the temperature of the sample chamber (take the average of three points) )) Compared with the original hardness value, its hardness must not be reduced by more than 15%.
5) Electrode is a consumable for industrial production, and the amount is relatively large, so its price cost is also an important factor to consider. Compared with its excellent performance, the price of chromium zirconium copper electrode is relatively cheap and can meet the needs of production.
6) The chromium-zirconium copper electrode is suitable for spot welding and projection welding of carbon steel plates, stainless steel plates, coated plates and other parts. The chromium-zirconium copper material is suitable for manufacturing electrode caps, electrode connecting rods, electrode heads, electrode holders, and projection welding special electrodes , Welding wheels, contact tips and other electrode parts.

The forming process of chromium zirconium copper material (CuCrZr):
Vacuum melting → hot forging (extrusion) → solid solution → cold forging (drawing) → aging treatment
The above process and strict quality control control ensure the material's excellent conductivity, high strength and good wear resistance.
The standard electrode heads, electrode caps, and special-shaped electrodes produced by the company adopt cold extrusion technology and precision machining to further increase the density of the product, and the product performance is more excellent and durable, and the welding quality is stable.
Round rod specifications are φ 3.0~45mm, squares or discs are generally forged according to customer requirements.

Beryllium Copper (BeCu)

Compared with chromium zirconium copper, beryllium copper (BeCu) electrode material has higher hardness (up to HRB95~104), strength (up to 800Mpa/N/mm2) and softening temperature (up to 650℃), but its conductivity is lower Much, worse. The beryllium copper (BeCu) electrode material is suitable for welding plate parts that are subject to greater pressure, and harder materials, such as seam welding wheels; also used for electrode accessories with higher strength requirements such as crank electrode connecting rods , A converter for robots; at the same time, it has good elasticity and thermal conductivity, which is very suitable for manufacturing stud welding chucks. The cost of beryllium copper (BeCu) electrode is relatively high, and we usually list it as a special electrode material.

Alumina copper (CuAl2O3)

Alumina copper (CuAl2O3) is also called dispersion strengthened copper. Compared with chromium zirconium copper, it has higher strength (up to 600Mpa/N/mm2), excellent high-temperature mechanical properties (softening temperature up to 900°C) and good electrical conductivity (Conductivity 80~85 IACS%), has excellent wear resistance and long life. Alumina copper (CuAl2O3) is a kind of electrode material with excellent performance, no matter its strength, softening temperature and conductivity are very superior, especially for welding galvanized sheets, it will not produce electrodes like chromium zirconium copper electrodes The phenomenon of sticking to the workpiece does not require frequent grinding, which effectively solves the problem of welding galvanized sheets, improves efficiency and reduces production costs. Alumina copper electrode has excellent welding performance, but its current cost is very expensive, so it can not be widely used at present, but the excellent welding performance of galvanized sheet and the universal use of galvanized sheet make its market prospects broad. Alumina copper electrodes are suitable for welding parts such as galvanized steel plates, aluminum products, carbon steel plates, and stainless steel plates

Tungsten (W), Molybdenum (Mo)

Tungsten electrode (Tungsten) Tungsten electrode materials include pure tungsten, tungsten-based high specific gravity alloy and tungsten copper alloy. Tungsten-based high specific gravity alloy is made by adding a small amount of nickel-iron or nickel-copper to tungsten. Tungsten-Copper composite material (Tungsten-Copper) ) Contains 10-40% (weight ratio) of copper.
Molybdenum electrode (Molybdenum) Tungsten and molybdenum electrodes have the characteristics of high hardness, high melting point, and excellent high temperature working performance. They are suitable for welding non-ferrous metals such as copper, aluminum, nickel, etc., such as the welding of copper braid and metal sheet of switches.