What is the importance of filler metal fluidity during brazing?

Filler metal fluidity during brazing plays a crucial role in achieving effective capillary action and ensuring joint integrity. When the filler metal has good fluidity, it can easily flow into the gaps between the base materials being joined. This capability allows the filler metal to form a strong bond by displacing any oxides or contaminants present at the joint interface.

Capillary action refers to the ability of the molten filler metal to travel into narrow spaces in the joint, which is essential for ensuring that all parts of the joint are adequately filled. Proper fluidity helps to maintain this capillary action, allowing the filler metal to be drawn into the joint by the surface tension of the liquid metal. Consequently, having a filler metal with optimal fluidity contributes to a complete and secure joint, ensuring that the brazed assembly is strong and durable.

Thus, the importance of filler metal fluidity cannot be overstated, as it directly influences the quality and reliability of the brazed joint.