What is brazing?

brazing
What does brazing mean?
Brazing refers to a welding method in which the filler metal and the welded part below the melting point of the welded part are heated to the melting temperature of the filler metal at the same time, and the liquid filler metal is used to fill the gap of the solid workpiece to connect the metal. When brazing, the oxide film and oil on the contact surface of the base metal should be removed first, so as to facilitate the capillary to play a role after the melting of the brazing material and increase the wettability and capillary fluidity of the brazing material. According to the different melting point of the solder, brazing is divided into brazing and soldering.
The brazing deformation is small, the joint is smooth and beautiful, and it is suitable for welding precision, complex and components composed of different materials, such as honeycomb structural plates, turbine blades, carbide tools and printed circuit boards. Brazing is one of the earliest material connection methods used by humans. When humans have not yet begun to use iron, brazing has been invented to connect metals. Among the ancient cultural relics unearthed in Egypt, there are pipes brazed with silver and copper brazing materials and amulet boxes connected with gold brazing materials. According to research, they are articles from years ago and recent years respectively. In the ruins of Pompeii, which was buried by a volcanic eruption in 79 A. D., there are remnants of domestic brazed water pipes connected by brazing. The brazing material used has a composition ratio of Sn:Pb = 1:2, similar to the brazing material used in modern times.
China also used tin-lead alloy brazing materials in the early Warring States period of the 5th century BC, and a large number of brazing techniques were also used in the bronze carriages of Qin Shihuang's terracotta warriors and horses. The brazing that was first seen in the literature in China was written in Han Shu by Ban Gu in the Han Dynasty: "Hu Tong's tears are like tears, and gold and silver can be welded, which is used by today's craftsmen".
What is brazing?
Brazing process: the surface cleaning good workpiece to lap type assembly together, the brazing filler metal on the joint gap near or between the joint gap. When the workpiece and the brazing filler metal are heated to a temperature slightly higher than the melting point of the brazing filler metal, the brazing filler metal melts (the workpiece is not melted), and is sucked into and filled with the gap between the solid workpieces by capillary action. The liquid brazing filler metal and the workpiece metal diffuse and dissolve each other, and the brazing joint is formed after cooling.