An experimental study on interference friction welding process

Abstract

Interference friction welding process is a variant of friction welding processes that has been proposed to be used to join a tube/round bar to a sheet metal/plate. The rotating tube is made to pass through the punched or drilled hole of smaller diameter and hence the interference causes the plastic deformation and frictional heat due to sliding contact in axial direction (due to tube feed) and tangential direction (due to tube rotation). In this investigation, the effect of different process parameters such as feed rate, spindle speed, amount of interference, and penetration depth of the tube on the axial thrust force and the torque generated at the weld interface has been studied. The change in torque and thrust force values were related to the amount of heat generation and plastic deformation at the interface that contributes to the quality of the solid state weld joint being formed. The quality of the weld joints formed at different parameters were evaluated from the microscopic analysis and shear testing. Moreover, the joint strengths were compared with the interference fit joints that were formed from the shrink fitting operation. It has been observed that, with appropriate process parameters, interference friction welding process can be performed on a typical machine tool, and it is feasible to create a weld with good joint strength.