To perform feasibility tests of friction stir welding (FSW) using different metals for weight reduction of weapon mounti

1. Military Systems Group Friction Stir Welding Applications for Military Vehicles Keith Lunkenheimer – Richard Teruya – Thomas Pearson – William Segale – John Vollmer Project Goal Materials Tested Feasibility Results To perform feasibility tests of friction stir welding (FSW) using different metals for weight reduction of weapon mounting brackets Magnesium (AZ31B) to Magnesium (AZ31B) Magnesium (AZ31B) to Aluminum (6061-T6) Aluminum Lithium (2090) to Aluminum (6061-T6) Motivation: Within the Special Forces: 1lb≈$100,000 operating costs/year Results for Mg to Mg Friction Stir Welding Mg is 34.5% lighter than Al but 13.4% weaker Al-Li is 4% lighter than Al and 45.3% stronger Process Parent Sample Tool Bit Results for Mg to Al Sample Tool Bit Tool Bit Tool Bit Tool Bit Tool Bit Tool Bit Tool Bit Tool Bit Sample Sample Sample Sample Sample Clamping Device Clamping Device Clamping Device Clamping Device Clamping Device Clamping Device Clamping Device Clamping Device During a weld, a rotating cylindrical tool is driven through the material to be welded This heats the material to a plasticized state and literally stirs the two pieces together Parameters: Plunge Depth, Traverse Rate, Tilt angle, Rotation Speed, Applied Force Friction Stir Welding Machine Close-up of FSW machine Results for Al-Li to Al Parameters for Optimization Mounting Bracket • Tool Geometry • Machine Improvement • - Force control - Auto Zero - Strength - More axes Test Sample Preparation Before FSW Test Sample Preparation After FSW Weight Savings Original 6061 design weighted 23.96 lbs With Al-Li: 20.35 lbs, a savings of ~3.5 lbs Cost Savings Modified Design employing FSW Original Design provided by MSG ~$350,000 savings/year if used by special forces