Views: 356 Author: Site Editor Publish Time: 2022-08-12 Origin: Site
The contact element is one of the components that need to be replaced frequently in the welding gun device. Its main function is to guide the wire, so that the current can be transmitted from the wire pipe to the workpiece through the wire. Its main functions include current transmission and wire positioning. Common contact elements include electrical contact rivets, silver clad copper strips, silver clad strips, etc.
The size of the contact element determines the size of the conductor that can be used and the amount of filler material that will be distributed during welding. When the contact element begins to wear, its conductivity will gradually decrease, which will greatly affect the ability of the welding gun guide wire to transmit current. In addition, the wire will begin to fluctuate. These conditions will eventually lead to poor arc starting, reduced penetration and reduced welding quality.
Types Of Common Contact Elements
Standard Copper Contact Element
The conductivity of standard copper is the best among all standard alloys, but its wear resistance is poor. As a common material, copper is softer than other metals, which means that it can make current transmission easier, but it also means that its melting point is low. As the temperature of the standard copper contact element increases, it becomes softer than the conductor. With the softening of copper, it is more easily worn, and its inner diameter will also change. This will lead to poor contact between the industrial contact element and the conductor, which will reduce the conductivity and eventually lead to the decline of welding quality.
Copper-Chrome-Zirconium Contact Element
Copper-chromium-zirconium contact elements are usually used in automatic welding equipment and robot welding equipment. These devices require precise TCP at runtime and will have a high duty cycle. Although the conductivity of this high performance contact element is lower than that of standard copper contact elements, its conductivity is sufficient for most applications.
In addition, because the melting point of copper-chromium-zirconium contact element is higher, it needs higher temperature to melt, which makes its service life often longer than that of standard copper contact element. Generally speaking, its melting point is 932 degrees Fahrenheit, while standard copper is about 500 degrees Fahrenheit. Therefore, materials with higher density have lower wear rate and can improve welding performance and productivity.
Silver-Plated CuCrZr Contact Element
With the progress of technology, the internal and external silver plating of CuCrZr contact element can further improve its overall performance.
Silver has better conductivity than copper, which helps to prolong the service life of contact elements, improve arc starting and improve welding quality. Silver has a density of about 17% higher than copper and a higher melting point. Silver has a shiny surface, which helps to reflect heat. Therefore, the spatter will not easily adhere to the contact element, thereby reducing the speed at which it is worn. In fact, the service life of silver-plated CuCrZr contact elements is 9 times longer than that of standard copper contact elements.
With the progress of material science, the cost of silver-plated contact elements is 50% higher than that of non silver-plated contact elements, but the use of silver-plated contact elements can reduce the downtime. Based on the overall life, current transmission and material quality, silver plated contact element is the best choice for automatic welding equipment and welding robot.