Friction-forging tubular additive manufacturing (FFTAM): A new route of solid-state layer-upon-layer metal deposition

Abstract

A new solid-state 3D-printing technology based on the friction-stir processing (FSP) treatment and forging consolidation is examined here for additive manufacturing (AM) to produce the tubular components in a layer-by-layer method, yielding extremely refined microstructure and attractive mechanical properties. Therefore, this novel technology can be termed “friction-forging tubular additive manufacturing (FFTAM)” as an alternative approach of sheet lamination (SL) process according to the ASTM designation for AM routes. In this research, the FFTAM process was accomplished to manufacture an Al–Al2O3 composite structure with a tubular shape design and a fully dense construction in the solid-state with continuous metallurgical bonding between the layers under the influence of hydrostatic pressure in combination with high temperatures generated by frictional-heating. A key finding is forming a superb high strength structure with an exceptional ultimate tensile strength (UTS) of around 900 MPa. This can be attributed to the significant grain structural refinement (down to less than 1 μm) and the homogenous incorporation of reinforcing alumina nanoparticles along with severe straining.

Keywords

• Friction stirring
• Forging consolidation
• Additive manufacturing
• FFTAM
• Sheet lamination (SL)
• Material characterization