A Feasibility Study on Friction Screw Extrusion Additive Manufacturing of AA6060

Additive manufacturingAdditive manufacturing in the solid state opens up possibilities for many alloys that are not suitable for fusion-based approaches. Following the advances in friction-based joiningJoining processes for high-strengthStrength aluminum and magnesium alloysMagnesium alloys, the Friction Screw ExtrusionScrew extrusion Additive ManufacturingAdditive manufacturing (FSEAM) process has been developed for deposition of thin layers for cladding and additive manufacturingAdditive manufacturing on a variety of substrates. In this work, the first results on the manufacturing of wall-like rectangular builds from AA6060T6AA6060T6 are reported. Multiple layers of about 15 mm width and 1 mm thickness were deposited with print velocities of 100–250 mm/min at constant toolTools rotation speed. Solid walls were formed without major macroscopic defects. Promising mechanical propertiesMechanical properties were measured with a yield strengthStrength of about 80 MPa and a tensile strengthTensile strength increasing from 112 to 144 MPa as function of the print velocity. The material was characterized by a fine microstructureMicrostructure with an average grain size below 10 μm for all builds. At the microscale, strings of unbonded regions have been observed at lower print velocities possibly related to insufficient mixing of the deposited material with the previous layer during manufacturing leading to reduced ductility. The observed results are encouraging, indicating that additive manufacturingAdditive manufacturing of aluminum alloys through FSEAM is feasible after further optimization of the process.