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.

The current work investigates the possibility of fabricating additive manufacturing products in solid-state form, from AA2011-T6 of 40 mm diameter rods as a feedstock, using an additive friction stir deposition (A-FSD) technique. The use of large diameter feedstocks, especially high-strength aluminum alloys (2XXX series), is a challenge, as it necessitates high power and the critical selection of the optimal A-FSD parameters, such as feed rate and spindle rotation speed. The study included applying a wide range of spindle rotation speeds, ranging from 400 to 1200 rpm, at three levels of feeding rates of 1, 3, and 5 mm/min. The AA2011-T6 friction stir deposited parts (FSDPs) were visually evaluated. This was followed by an examination of macrostructures through the thickness of the fabricated specimens. The characterization of microstructures was also carried out using optical microscopy and a scanning electron microscope equipped with advanced EDS analysis. Furthermore, the mechanical properties in terms of hardness and compressive strength of the AA2011-T6 base material (BM) and deposited materials were evaluated. Sound, additively manufactured products were successfully fabricated from 40 mm diameter AA2011-T6 feedstocks using the suggested deposition variables of 600 and 800 rpm spindle speeds and feeding rates of 1, 3, and 5 mm/min. The results indicated that the spindle speed and feeding rate govern the quality of the FSDPs. Furthermore, the axial load during the A-FSD process increased with increasing these parameters. In comparison to the AA2011-T6 BM, the additively deposited materials showed a refined grain structure and uniform dispersion of the fragment precipitates in their continuous multi-layers. The reduction ratio in grain size attains 71.56%, 76%, and 81.31% for the FSDPs processed at 800 rpm spindle speed and feeding rates of 1, 3 and 5 mm/min, respectively, compared to the grain size of BM. The Al₂Cu and Al₇Cu₂Fe intermetallics are detected in the AA2011-T6 BM, and their deposited parts are in different shapes of spherical, almost spherical, irregular, and rod-like shapes. The compressive strength and hardness of the deposited parts increased with increasing spindle speed and feeding speeds. At a spindle speed of 800 rpm and a 5 mm/min feeding rate, the higher hardness and compressive strength gained were 85% and 93%, respectively, from that of the AA2011-T6 feedstock.