Brazing Holding Time
The brazing holding time is the time the brazing zone is held at brazing temperature to ensure complete diffusion and metallurgical interactions. Too short or too long holding times can lead to phase formations.
Physico-Chemical Mechanism of Action
Brazing holding time refers to the time during which the braze zone is held at the desired temperature. This temperature enables complete diffusion of metals and compounds between the workpieces. The correct holding time is critical for a homogeneous joint and prevents phase formations that can lead to weak points.
Metallurgical Relevance & Risks in Welding
A too short brazing holding time can cause that not all metals fully diffuse and do not bond well. This can lead to incomplete joints or weak points in the braze. Conversely, a too long holding time can cause phase formations such as silicon crystals or other intermetallic compounds, which impair the strength and toughness of the material.
Workshop Practice & Operating Instructions
The brazing holding time should be precisely followed. For certain materials and joints, specific recommendations are given in welding handbooks or manufacturer's documentation. For example, in silicon brazing, the holding time should be between 10 and 20 seconds. Monitor the temperature closely with a thermostat and keep the braze zone constantly at the specified temperature.