What is forge force in Friction Stir Welding, and why is it important?

Forge force refers to the downward force applied by the welding tool during Friction Stir Welding to consolidate the softened material and form a solid, defect-free joint. It’s a critical parameter that directly affects weld integrity, mechanical properties, and surface finish.

Maintaining the right forge force ensures proper material flow beneath and around the tool, helping to eliminate internal voids and achieve full consolidation of the joint. Too little force can lead to incomplete bonding, while too much can cause surface defects or tool wear. Precise control of forge force—often through hydraulic or servo-driven systems—is essential for producing high-quality, repeatable welds, especially in aerospace and automotive applications.