Compatibility of AL alloys for spot welding

[Philrock]

I'm designing a sheet metal weldment that requires the use of an aircraft continuous hinge (MS20001) made of AL 2024 or 7075. The spec for the hinge says it can be either alloy, and the vendor can not tell me which alloy it will actually be. I want to spot weld the hinge to a sheet of 6061-T6. Are 2024 and/or 7075 compatible with 6061 for spot welding? The application is not aircraft, and no vibration is present, but shear stresses in the spot welds will be fairly high - in the neighborhood of 15 ksi.

 

[Ron]

2024 has poor weldability. 7075 is weldable. In either case, 15ksi is much too high of a shear stress. You will need a much larger weld than a spot weld.