What is Controlled Atmosphere Brazing (CAB)?
Controlled atmosphere brazing, also known as brazing, is an effective method of joining different metal components together in a single piece. This process employs a molten filler material, such as copper or aluminum alloys, to bond the parts. The filler can come in the form of a paste, ring or sheet and flows between the joined surfaces due to capillary action.
During the process, the molten filler material interacts with the base metals, forming a metallurgical bond as it solidifies and cools. This technique is characterized by the creation of joints that are resistant and ductile, maintaining a strength equal to or greater than the original materials. In addition, it is ideal for applications that require a tight seal, such as in the confinement of fluids or gases.
The environment of the welding furnace is adjusted to prevent rust. Oxidation can interfere with the flow of the filler material, thus compromising the quality of the joint. Therefore, the oxygen in the furnace is replaced by an oxygen-free mixture, usually composed of hydrogen and nitrogen, ensuring clean, high-quality bonds.
What is Controlled Atmosphere Brazing (CAB)?
Controlled atmosphere brazing, also known as brazing, is an effective method of joining different metal components together in a single piece. This process employs a molten filler material, such as copper or aluminum alloys, to bond the parts. The filler can come in the form of a paste, ring or sheet and flows between the joined surfaces due to capillary action.
During the process, the molten filler material interacts with the base metals, forming a metallurgical bond as it solidifies and cools. This technique is characterized by the creation of joints that are resistant and ductile, maintaining a strength equal to or greater than the original materials. In addition, it is ideal for applications that require a tight seal, such as in the confinement of fluids or gases.
The environment of the welding furnace is adjusted to prevent rust. Oxidation can interfere with the flow of the filler material, thus compromising the quality of the joint. Therefore, the oxygen in the furnace is replaced by an oxygen-free mixture, usually composed of hydrogen and nitrogen, ensuring clean, high-quality bonds.
Brazing Operation in a Controlled Atmosphere
The parts are moved through a furnace in an environment controlled by a conveyor belt. The atmosphere inside the furnace is free of oxygen and consists of nitrogen or hydrogen. The typical process in a production line includes:
- Cleaning and/or degreasing of components.
- Pre-assembly by mechanical adjustment or by TIG welding.
- Application of paste or rings of filling material.
- Preheating (depending on the type of oven).
- Heating.
- Performing brazing.
- Cooling.
Is brazing right for my needs?
This technique is ideal for joining metal parts where a strong, leak-free joint is required. It is faster and cheaper than other methods such as soldering or TIG. In addition, it is very suitable for medium and large-scale productions.
Brazing is especially effective for:
- Small parts with complex geometries.
- Large elements with irregular shapes.
- Mass production.
- Parts that must withstand high temperatures (350 degrees or more) continuously.
Advantages of Controlled Atmosphere Brazing
The CAB process offers multiple benefits:
- Clean aesthetics: No need to clean the solder points as no flux is used.
- Cost reduction: A conveyor system reduces the cost per part.
- Process consistency: By dispensing with flux and controlling the heating phases, a very uniform process is ensured.
At EMS Group, we use this method as an alternative to TIG welding, both on small components and sub-assemblies that are then integrated into larger parts, welded manually or robotically.
If you consider that any of your parts can benefit from the controlled atmosphere brazing (CAB) process in the furnace, do not hesitate to contact us.
At EMS Group, innovation and customer satisfaction are our priority!
