Augmented Heating of Dissimilar Metals to Improve Joinability of Friction Welds

All solid-state welding methods employ some variation of heat and deformation to accomplish bonding. Heat and deformation are key to bringing working surfaces into intimate contact, displacing surface oxide-based contaminants, and allowing solid state bonding of the substrates. Friction welding methods accomplish this through relative motion of the materials under force. Implicit in traditional friction welding technology are large variations in shear loads particularly during the initial stages of the process. This load variation is a major consideration for machine robustness, tooling design, process set-up, part design, material selection, and overall cost. As an innovation to reduce these initial process loads, the use of resistance-based pre-heating has been investigated. The approach enables raising workpiece temperatures to plasticization temperatures in very short times (100’s of milliseconds) and offers a uniform through thickness heating profile. This proposal addresses our use of the resistance based pre-heat augmented process, and our approach at investigating the capability of modeling the �Low Force� technology for bonding dissimilar Titanium alloys to be used in blisk production. This includes examination of process variations as the performance attributes.