Brazing is a method that uses a filler metal with a melting point lower than that of the base material. The workpieces (base materials) and the filler are heated to a temperature above the melting point of the filler but below that of the base material, allowing the liquid filler to wet the base material, fill the joint gap, and diffuse with the base material to achieve a connection. However, before brazing, the surface of the workpieces needs to be treated, and specific details will be introduced below.

      Brazing TechnologySurface Preparation Work Before Brazing

1. Surface Treatment of Workpieces

The surface treatment of workpieces before brazing includes degreasing, removing oxide films, and coating the surface of the workpieces. The coating on the surface of the workpieces is intended to improve the wettability of the filler on certain substrate materials and to prevent severe oxidation during brazing and the formation of brittle compounds in the filler.

2. Fixing of Brazed Joints

When designing brazed joints, it is essential to consider making the assembly and positioning of pre-weld parts simple yet accurate. For larger and more complex parts, specialized fixtures are generally used for positioning and clamping. At this time, joint design is not restricted, but there are higher requirements for fixtures, such as high-temperature resistance, oxidation resistance, and sufficient strength and rigidity.Brazing Technology

3. Pre-setting and Positioning of Filler

When designing joints, it is necessary to determine what shape of filler will be used and how it will be fed into the joint gap. Typically, gas flame brazing and soldering use fillers fed during brazing, while other brazing methods usually involve pre-placing the filler on the joint.