Torque Control of Friction Stir Welding

Period of Performance: 01/01/2011 - 12/31/2011


Phase 1 STTR

Recipient Firm

Longhurst Engineering, PLC
234 South Ewing Street
Guthrie, KY 42234
Principal Investigator

Research Institution

Vanderbilt University
2400 Blackmore Ave
Nashville, TN 37212
Institution POC


Longhurst Engineering, PLC and Vanderbilt University propose the innovation of torque control of friction stir welding (FSW) as a replacement to force control of FSW. The value of the torque is significant because it indicates how far the tool is plunged into the work piece. Proper engagement of the tool into the work piece is critical for producing reliable welds.The commercialized innovation will consist of three elements. First, a FSW tool will be developed to produce a linear relationship between the welding torque and the tool's plunge depth into the work piece. Second, the welding torque will be measured from outside the welding environment via thespindle motor current, thus eliminating the need for expensive force sensors associated with force control. Third, a closed-loop architecture will be designed and implemented to control the welding torque.