Welding Very Thick to Ultra Thin Metals but NO Heat Affected Zone

Joining thick aluminum or thin sheets of stainless steel are some of the more challenging welds for the aerospace industry. Joining parameters couldn’t be more different between steel and aluminum. But what if we can reduce all the variables down to three – induction, shear and forge in an inert environment regardless of thickness, geometry or material?

To date Titanium, Stainless and Zirconium have been joined using solid state induction in tubular form. This technique, the science applies to flat and curved geometry.

Result is a weld that is fine grained base to base, no fusion line, no stress riser. Induction supplies over 95% of the energy required, shear and forge less than 5% (EWI 2012). The world’s largest linear friction machine is able to join 15 in2 +/-. By substituting linear friction energy w/ induction between the work faces, equipment size can be reduced or parts to be joined can be increased. Technique can change the economics of net shape manufacturing. And switch from hydraulics to electric.

Another fundamental difference between linear friction and solid state induction weld is profile, grain flow and flash. Friction produces fusion line, sharp flash edges and material consumed at the last moment vs smooth profile, laminar grain flow and minimal material consumed. Heat penetration is in millimeters.

Friction stir welding (FSW) is serving the aerospace industry well joining aluminum sheets up to certain thickness. FSW for tubular is still under research. Solid state induction has no such limitations. Technique is vacuum / gravity neutral so welding in Space is realistic. As NASA stated 2020: the potential to revolutionize how orbiting platforms are designed, manufactured, and assembled.

Solid State induction welding opens new branch of manufacturing – lower cost, better quality.