What Is Cold Welding? Advantages and Disadvantages
There are numerous types of welding, and cold welding is different from other types because little to no heat is used to weld the pieces together.
This type of welding has been around since the 1940s and is often used to weld wires together and to weld two pieces of metal together in space, among other tasks. Below are some details about cold welding that you likely didn’t know.
What Exactly Is Cold Welding?
Cold welding involves joining two metals together without any type of fusion or heating of the different parts. Instead of any type of heat, this type of welding – also called spot welding or resistance welding – uses pressure to get the job done.
After tremendous pressure is used, an electrical current is passed through the metal, and it is this electricity that causes the metals to mold together. The current causes the surface of the metals to heat up, which causes the atoms to move around and form new compounds. These compounds are super-strong and hold the metals together forever.
If you need pieces of metal permanently joined together, cold welding is the process to consider. Having said that, the process isn’t for every job because you have to damage the materials in order to get them apart, making it very difficult to do. There are also advantages and disadvantages to the cold welding process, which we’ll discuss now.
Advantages of Cold Welding
Some of the advantages of cold welding include:
- They offer welds that are very clean and strong.
- It doesn’t form brittle intermetallic compounds at the join.
- There is no heat-affected zone (HAZ) that results in mechanical changes or negative chemical changes to the base materials you’re joining.
- It even works on aluminum, including aluminum 2xxx and 7xxx series.
- You can join dissimilar metals, such as copper and aluminum.
Disadvantages of Cold Welding
Some of the disadvantages of the cold welding process include:
- It cannot be used on all metals, only metals that are ductile and which haven’t undergone a severe hardening process; this includes metals with any type of carbon.
- Your materials must be clean and oxide-free to turn out right, which is sometimes difficult.
- The shape of the material has to be just right, meaning no irregular shapes and no surface irregularities; flat and regular surfaces work best.
Other Unique Characteristics
The cold welding process is good for metals such as 70/30 brass alloys, gold, silver alloys, copper, silver, nickel, and zinc.
Stainless steel works, too, but you’ll need a lot of pressure to make it work. Carbon metals, unfortunately, do not work with this type of welding. It is a unique but very reliable welding technique that is perfect for metals that need to be fused together permanently.
It is also a common process in certain industries, including both automotive and aerospace, and it is typically used for joining wires together.
While there are some challenges when using the cold welding method, it is a great method when you want to weld dissimilar pieces together and when you want the final product to be tough and permanent. As always, be sure to wear protective equipment while you are welding at any time for your safety.