Metal brazing is accomplished by melting a metal between two metals and through capillary action, a bond is formed. The melted metal flows into all the cracks and crevices between the metals to be joined. This forms a permanent bond which is extremely strong. Controlled atmosphere brazing (CAB) is commonly used because of its effectiveness.
Brazing is Not Welding or Soldering
Some people confuse the terms “brazing” and “welding” but they are not the same thing. When two metals are brazed, the work pieces are not melted on the brazing material. Soldering is similar to brazing methods but brazing is done under much hotter temperatures. This creates a much tighter bond than soldering.
Controlled Atmosphere
Inert gases are usually used in controlled atmosphere brazing methods. This could be nitrogen, argon, or even helium. However, due to cost factors, nitrogen is the preferred gas.
To control the environment, a vacuum furnace is the best option. This way, oxygen can be pumped out and nitrogen can be introduced into the environment. The process of atmosphere brazing can be quite complex, depending on the application.
Why Control the Atmosphere?
A controlled atmosphere refers to conditions closely monitored. For example, some types of metal treatment should not have oxygen in the air, because it can be very corrosive. Oxygen is synonymous with rust, hence the term “iron oxide,” which is basically rusted metal.
Oxygen is not the only contaminant to keep out. Atmosphere brazing can completely control the environment and this can eliminate all kinds of contaminants including water vapor and carbon. A controlled environment creates metals with the right properties for the needs of industry.
Benefits of Controlled Atmosphere Brazing
Brazing metals is nothing new and has been with us for thousands of years. However, controlled environment methods provide a variety of benefits. For example:
- Less weight – this is extremely important for the aircraft and automotive industries.
- Bonds can be guaranteed not to leak
- Increased strength – besides making things stronger, the strength is evenly distributed.
- Machining is sometimes eliminated – this results in greater overall efficiency.
- Stronger parts and structures
- Greater variety of parts
Why You Need Professionals for Controlled Atmosphere Brazing
Some types of metal brazing can be done on the job site. However, if you need special brazing under controlled environments, you should have the right equipment. This equipment can be very expensive to purchase and operate and this is the main reason most businesses rely on metal brazing and annealing services. Your professional metal working company can serve a variety of your needs.
