Copper Welding Is Difficult, Can Ordinary Welding Machines Handle It? Do You Need Any Special Techniques?

Copper, with its excellent electrical and thermal conductivity as well as corrosion resistance, is widely used in electronics, power, refrigeration and other fields. However, in actual production, copper welding often poses a headache for operators - - weld points are prone to virtual connections, porosity, and even failure to weld through. This inevitably raises questions: Why is copper welding so difficult? Can ordinary welding machines handle it? And is special technology required?

 I. The Difficulty of Copper Welding: "Innate Challenges" from Material Properties

The high difficulty of copper welding mainly stems from its unique physical properties, which bring three major "innate challenges" to the welding process:

First is the high thermal conductivity that "takes away heat". Copper's thermal conductivity is about five times that of low - carbon steel. During welding, the input heat is quickly conducted and diffused by the copper material, making it difficult for the molten pool temperature to stay above the melting threshold. This easily leads to problems like "welding not through" and "lack of fusion", especially for copper materials thicker than 3mm, where heat loss is more pronounced.

Second is the easy oxidation that "destroys the molten pool". Copper reacts quickly with oxygen at high temperatures (above 300℃) to form a dense layer of copper oxide film. This film has a melting point as high as 1326℃, far above copper's own melting point of 1083℃. If not removed in time, it will remain in the molten pool, causing porosity and slag inclusion, which directly reduces the weld point strength.

Third is the strong fluidity that "makes it difficult to form". Copper liquid has much higher fluidity than steel liquid. If not properly controlled during welding, the copper liquid is prone to loss, resulting in poor weld point formation and even "burn - through" of thin - walled copper pieces.

II. Ordinary Welding Machines "Fall Short": Unable to Meet the Welding Needs of Copper

Faced with the welding challenges of copper, ordinary welding machines (such as conventional arc welders and ordinary spot welders) often "fall short" and fail to meet quality requirements. The main problems are focused on two aspects:

On the one hand, the energy output is "not precise". Ordinary arc welders have a relatively narrow range of current and voltage adjustment, and the energy is dispersed. They cannot provide concentrated and stable heat for copper's high thermal conductivity. Either the heat is insufficient, leading to incomplete welding, or the heat is excessive, burning thin - walled pieces. Ordinary spot welders, on the other hand, suffer from copper's high electrical conductivity, which causes the current to disperse easily and makes it difficult to form a large enough molten core. The weld point strength is far below the required level.

On the other hand, there is a lack of "oxidation protection". Most ordinary welding machines do not have a dedicated inert gas protection system. During welding, copper is in direct contact with air, and the oxide film continues to form. Even if the welding is勉强completed, the weld point will become fragile due to oxidation defects and will not be able to withstand vibration and pressure during long - term use.

III. Copper Welding Requires "Special Technology": Full - Process Optimization from Preheating to Protection

To overcome the difficulties of copper welding, targeted special technology must be used to form a complete optimization plan from before, during and after welding:

Before welding, "pre - treatment" is needed. First, the surface of the copper material should be ground and acid - washed to thoroughly remove the oxide film and oil contamination to prevent impurities from entering the molten pool. Second, preheating should be carried out according to the thickness of the copper material. Copper materials with a thickness of 3 - 10mm should be preheated to 200 - 350℃, and those with a thickness of more than 10mm should be preheated to 350 - 500℃. Preheating slows down heat loss and creates conditions for the stability of the molten pool.

During welding, "precise energy control + oxidation prevention" is required. Choose welding methods with concentrated energy, such as pulsed MIG welding and laser welding. Pulsed MIG welding can release high energy in an instant through high - frequency pulsed current, overcoming copper's heat loss. It is also combined with argon protection to isolate the air. Laser welding focuses energy with a spot size at the 0.01mm level, quickly melting copper and keeping the heat - affected zone to 0.1 - 0.3mm to avoid deformation. In addition, special welding materials should be selected, such as phosphor - bronze welding wire and silicon - bronze welding wire. These materials can form good alloys with copper and inhibit the formation of oxide films.

After welding, "slow cooling" is needed. Wrap the weld point with insulating cotton after welding to let it cool slowly, reducing internal stress caused by large temperature differences and avoiding cracks.

Copper welding has extremely high requirements for equipment performance and process details, and ordinary welding machines and conventional processes are difficult to meet the needs. If you have copper welding needs, PDKJ's welding machine has optimized the energy control system for copper characteristics, equipped with special oxidation - prevention protection modules and process plans, and can accurately solve the problems of copper welding not through and easy oxidation, ensuring the strength and stability of the weld points and providing reliable guarantees for production.

If you have welding machine requirements, please contact Ms. Zhao

E-Mail: pdkj@gd-pw.com

Phone: +86-13631765713