The Additive Manufacturing of Aluminum Matrix Nano Al₂O₃ Composites Produced via Friction Stir Deposition Using Different Initial Material Conditions

The current work investigates the viability of utilizing a friction stir deposition (FSD) technique to fabricate continuous multilayer high-performance, metal-based nanoceramic composites. For this purpose, AA2011/nano Al₂O₃ composites were successfully produced using AA2011 as a matrix in two temper conditions (i.e., AA2011-T6 and AA2011-O). The deposition of matrices without nano Al₂O₃ addition was also friction stir deposited for comparison purposes. The deposition process parameters were an 800 rpm rod rotation speed and a 5 mm/min feed rate. Relative density and mechanical properties (i.e., hardness, compressive strength, and wear resistance) were evaluated on the base materials, deposited matrices, and produced composites. The microstructural features of the base materials and the friction stir deposited materials were investigated using an optical microscope (OM) and a scanning electron microscope (SEM) equipped with an EDS analysis system. The worn surface was also examined using SEM. The suggested technique with the applied parameters succeeded in producing defect-free deposited continuous multilayer AA2011-T6/nano Al₂O₃ and AA2011-O/nano Al₂O₃ composites, revealing well-bonded layers, grain refined microstructures, and homogeneously distributed Al₂O₃ particles. The deposited composites showed higher hardness, compressive strengths, and wear resistance than the deposited AA2011 matrices at the two temper conditions. Using the AA2011-T6 temper condition as a matrix, the produced composite showed the highest wear resistance among all the deposited and base materials.