When it comes to any type of welding project, the material that you work with has a significant impact on the process and result. Copper and aluminum are two popular materials, for example. If you’re choosing between these two, understand the differences to know which is right for your welding services.

Copper Welding

Characteristics

Copper is a soft and ductile material. Unlike steel, it can only be hardened by cold working, as heat treatment will diminish its strength. It has excellent thermal and electrical conductivities and is highly resistant to fatigue and corrosion. Copper alloys can be used for surfaces that require minimized bacteria levels, making it a good touch surface for hospitals, schools, and other public areas.

Challenges

Many copper alloys are highly sensitive to hot cracking since the metal weakens with heat. This means they are not ideal for welding and should be joined by soldering or brazing instead. With the right filler metals, however, pure copper alloys can be best welded with gas shielded arc methods. The best filler metals tend to be those with deoxidants such as manganese and silicon. Hydrogen control must be done to minimize porosity, and high purity shield gases should be used.

Aluminum Welding

Characteristics

Aluminum has a melting point of 1,221 degrees Fahrenheit, which is much lower than steel. Its oxide layer has a melting point of around 3,700 degrees. Because that oxide layer is much harder than the underlying aluminum, it makes the result more resistant to abrasion and corrosion. Unlike steel — which gets more brittle in lower temperatures — aluminum gets stronger, making it an ideal choice for cold temperature applications.

Challenges

The oxide layer around aluminum presents some unique welding challenges because it acts as an insulator for the metal. When aluminum becomes liquid, it will absorb hydrogen along with the filler metal. However, once it starts to solidify, that hydrogen forms bubbles and causes porosity in the result. A shielding gas mixture of helium and argon can be used to combat this issue.

An experienced welder knows the unique benefits and challenges of each metal and will use their knowledge to give you the result you need. The team at Brady’s Welding Specialties have been working in welding repair for over 40 years in Tacoma, WA. They offer mobile services to save you money and time and have earned an A+ rating with the Better Business Bureau® for their exceptional customer service. Learn more about their welding online and call (253) 475-4608 to discuss your project.