A New Approach for Enhancing Friction Welding Joint Strength

The current research provides a new approach for enhancing the mechanical characteristics of friction welding joints for AA 6061 T6. Friction welding depends on the contact surface area between the two parts that need to be welded to generate the frictional heat necessary for the welding process. The frictional area is increased by modifying the contact area from flat circles on both sides of the joint to three different design configurations: a truncated cone, a half sphere, and a cylinder along with their opposite cavity. Mechanical characteristics and microstructural behavior for the new joints are studied. It was elucidated that the conical design configuration is the only one that succeeded through specimen manufacturing, welding, and testing procedures. The results show an improvement in the tensile strength of the truncated cone by 12% compared to the basic flat circle configuration. Bending and Vickers Micro-Hardness (HV) also increased in the joint cross-section by 10% and 7%, respectively. The results are consistent with the microstructure tests where the cone design configuration exhibited a finer grain structure than that of the flat circle. This proves that the generated heat is greater in the new design configuration. Thus, it can be said that the current study provides a promising approach for the improvement of friction welding joint strength.