Additive Friction Stir Deposition

Additive Friction Stir Deposition (AFSD) is an Additive Manufacturing (AM) technology that is well-suited for both new fabrication and the repair of existing articles. AFSD uses stirring friction and benefits from the material always remaining in its solid phase, thus retaining good structural properties and eliminating any of the porosity, cracks, and residual stresses caused by the melting-solidification process.

In AFSD, a high-speed rotating stirring tool print head deposits the feedstock at temperatures below the material melting point. Dynamic friction from the interaction of the print head, material to be deposited, and the previously deposited material (or substrate) causes the material to heat, soften, plastically deform, and bond. The result is a metal with fine, equiaxed, and crystalized grains.

AFSD deposition at the ES3 facility in Clearfield, Utah.

ES3 has a MELD Manufacturing AFSD machine to which we have made custom nozzle and cooling system upgrades that has significantly reduced the heat effected zone. Our R&D work is addressing grain growth for optimal mechanical properties in new build fabrications. As a result, we are now producing AFSD formed metals with mechanical properties that sufficiently meet and, in some cases, exceed the properties of traditionally forged or cast parts.  Our fabrication times are a fraction of those for forged or cast parts.  And most surprisingly, our current estimated cost for a production run on a particular aerospace part is less than one which was cast.

Specifically, ES3 has successfully AFSD formed the following materials:

  • Al 7075
  • Al 7050
  • AL 6061
  • T6
  • T7
  • T651
  • T73

along with their multiple tempers.

ES3 is currently performing final qualification testing of AFSD formed parts for several aerospace applications.