Brazing in essence, a group of joining processes, is used to produce coalescence of different metals. Metals are heated to their brazing temperatures and then filled in with a filler metal which is also known as solder. Note here that the temperature such that it’s above the melting point of the filler metal and below that of the base metal.
How Brazing Works
Through the process of brazing, a metallurgical bond is created between the solder metal and the base metal. The base metal is heated to a temperature just below its melting point, which is the solder metal’s melting point. Once the base metal has acquired the temperature, the solder metal is brought in contact with the heated parts of the base metal. This causes the filler metal to melt which is then drawn into the base metal through the capillary action. The resultant product is a brazed joint.
Uses of brazing joints
Brazing has been the key metal joining process since decades. It’s used to fabricate refrigeration, air-conditioning and heating equipments. A typical HVAC unit generally contains hundreds of such brazed joints.
Brazing is a common process of creating alloys for copper. It’s used to connect copper tubes to return bands, fins and headers and shells to tube bundles. The process of brazing is used to join both similar and dissimilar metals, thick and thin sections and metals that whose melting points differ widely.
Another reason why brazing is so popular is because it produces leak proof joints which are critical in HVAC units. HVAC systems are typically closed units that contain special gasses or liquids that act as a cooling or heating medium. Leaking joints would cause these heating or cooling liquids or gasses to escape leading to the equipment malfunctioning.
Besides, brazed joints are easy to construct, produces strong leak-free joints that are stronger and is economical too.
