1. Copper Chrome Zirconium (CuCrZr)
Copper Chrome Zirconium (CuCrZr) is the most used material for resistance welding electrodes, determined by its excellent physicochemical properties and cost-benefit.
1) Zirconium chromium copper electrode achieves a good balance in four performance indicators for welding electrodes:
★ Excellent conductivity ensures that the impedance of the welding circuit is minimized, resulting in high-quality welding.
★ High temperature mechanical properties – higher softening temperature ensures the performance and service life of the electrode material under high temperature welding conditions.
★ Wear resistance – the electrode does not wear out easily, extending its useful life and reducing costs.
★ Greater hardness and resistance – ensures that the electrode head does not deform easily under certain pressures, ensuring welding quality.
2) Electrodes are consumable items in industrial production and are used in large quantities. Thus, its price and cost are important considerations.
Given their superior performance, chromium zirconium copper electrodes are relatively inexpensive and can meet production needs.
3) Copper and chromium-zirconium electrodes are suitable for spot welding and projection welding of carbon steel plates, stainless steel plates and coated plates.
Zirconium chromium copper material is suitable for manufacturing electrode caps, electrode leads, electrode heads, electrode cables, special projection welding electrodes, welding wheels, conductive nozzles and other electrode parts.
2. Beryllium Copper (BeCu)
Compared to zirconium copper, beryllium copper (BeCu) electrode material has higher hardness (reaching HRB95 ~ 104), strength (up to 800Mpa/n/mm 2 ) and softening temperature (up to 650°C). However, its electrical conductivity is significantly lower, which is less desirable.
Beryllium Copper (BeCu) electrode material is suitable for welding sheet metal parts that are under considerable pressure, as well as harder materials such as seam welding wheels used for weld seam welding.
It is also used for some high-resistance electrode components, such as crank electrode connecting rods and transformers used by robots, due to its excellent elasticity and thermal conductivity. It is very suitable for manufacturing welding tongs for pin welding.
Despite its high cost, beryllium copper (BeCu) electrode is often classified as a special electrode material.
3. Aluminum Oxide Copper (CuAl2O3)
Aluminum oxide copper (CuAl2O3), also known as dispersion-strengthened copper, has higher strength (up to 600Mpa/n/mm 2 ) compared to zirconium copper.
It features excellent high-temperature mechanical properties (softening temperature reaches 900°C) and good electrical conductivity (conductivity rate 80~85IACS%), along with exceptional wear resistance and longevity.
Copper Aluminum Oxide (CuAl 2 Ó 3 ) serves as an exceptional electrode material, distinguished by its superior strength, softening temperature and conductivity. It is particularly excellent when used to weld galvanized plates, as it does not produce adhesion between the electrode and the workpiece like copper and zirconium electrodes.
This eliminates the need for frequent grinding, effectively addressing the challenge of welding galvanized sheets, thus increasing efficiency and reducing production costs.
Although aluminum copper oxide electrodes offer excellent welding performance, their current production cost is significantly high, which prevents their widespread use.
However, its excellent welding properties for galvanized sheets and the widespread use of these sheets present a promising market prospect.
Aluminum copper oxide electrodes are used to weld parts made of galvanized steel plates, aluminum products, carbon steel plates and stainless steel plates.
4. Tungsten (W) and Molybdenum (Mo)
tungsten electrode
Tungsten electrode materials include pure tungsten, high-density tungsten alloys and tungsten-copper alloys.
High-density tungsten alloys are created by sintering a small amount of nickel-iron or nickel-copper into tungsten, while tungsten-copper (tungsten-copper) composite materials contain 10-40% (by weight) copper.
molybdenum electrode
Tungsten-molybdenum electrodes feature high hardness, high melting points and superior performance at high temperatures, making them suitable for welding non-ferrous metals such as copper, aluminum and nickel – such as connecting the braided copper tape of a switch and a metal sheet.
Table of physical-chemical properties of CuCrZr
a) Chemical Composition and Physical Properties of CuCrZr
b) 1) CuCrZr (chromium-zirconium-copper) molding process
Vacuum Melting – Hot Forging (Extrusion) – Solid Melting – Cold Forging (Pulling) – Aging Treatment
The above process, in combination with strict quality control, guarantees excellent electrical conductivity, high strength and good wear resistance of the material. The electrode heads, electrode caps and special-shaped electrodes produced employ a cold extrusion process and precision machining, further increasing the product density. The improved product performance is more excellent, durable and ensures stable welding quality.
2) Chemical Composition
| Element | Cr | Zr | Yes | mg | Ass |
| Happy (%) | 0.7-1.0 | 0.08-0.2 | Tracking Quantity | Tracking Quantity | Balance |
3) Physical Properties
| Material form | Round shank | Blocks/disks |
| Specific gravity (p) (g/cm 3 ) | 8.9 | 8.9 |
| Hardness (HRB) | 80-85 | 78-82 |
| Conductivity (IACS%) | 80-85 | 75-80 |
| Softening temperature (℃) | 550 | 550 |
| Elongation rate (%) | 15 | 15 |
| Tensile strength (MPa/n/mm 2 ) | 420 | 420 |
c) Chemical Composition and Physical Properties of Al2O3Cu and BeCu
1) Chemical Composition
| Element content (%) | A1203 | Ass |
| A1203Cu | 0.8-1.0 | Balance |
| Element content (%) | To be | No | Ass |
| BeCu | 0.4-0.5 | 1.0-1.5 | Balance |
3) Physical Properties
| Material form | A1203Cu | BeCu |
| Specific gravity (P) (g/cm 3 ) | 8.9 | 8.9 |
| Hardness (HRB) | 73-83 | ≥ 95 |
| Conductivity (IACS%) | 80-85 | ≥ 50 |
| Softening temperature (℃) | 900 | 650 |
| Elongation rate (%) | 5-10 | 8-16 |
| Tensile strength (MPa/n/mm 2 ) | 460-580 | 600-700 |
Instructions:
1) The analysis of the chemical composition of the alloy is carried out according to the guidelines of ZBH62-003.1-H62003.8.
2) The hardness of the alloy is determined according to GB230, with each sample tested at three points and the average value obtained.
3) Conductivity is measured using an eddy current conductivity meter (eddy current comparison method). Each sample is tested at three points and the average value is obtained. For samples with a diameter of less than 15 mm, measurements may be made in accordance with the provisions of GB3048.2.
4) For the softening temperature test, the sample is placed in an oven heated to 550°C (after closing the oven door, it is necessary to return to this temperature and maintain it for 2 hours before cooling the temper). The ambient temperature value of the sample chamber (average of three points) is measured and its hardness, compared to the original hardness, should not decrease by more than 15%.
