What is the direction of flow for the filler metal and the flux when joining pieces?

In the process of brazing, understanding the flow of filler metal and flux is crucial for effective joint formation. The filler metal is drawn into the joints through capillary action, which occurs as the heat melts the filler metal and it flows into the space between the pieces being joined. This movement is often described as the filler metal flowing "in" towards the joint area.

Simultaneously, the flux serves to protect the joint from oxidation and assists in cleaning the metal surfaces. Flux also travels into the joint area, ensuring that impurities are removed and that the filler metal can bond effectively to the base metals. Therefore, both the filler metal and the flux flow "in" toward the joining surfaces, emphasizing the significance of proper flux application alongside the filler metal to achieve a strong, clean bond.

This understanding of flow direction is essential for anyone involved in the brazing process, as it guarantees that both the filling and cleaning agents are working in harmony to create a reliable and durable joint.