  Citation: El-Sayed Seleman, M.M.; Ataya, S.; Ahmed, M.M.Z.; Hassan, A.M.M.; Latief, F.H.; Hajlaoui, K.; El-Nikhaily, A.E.; Habba, M.I.A. The Additive Manufacturing of Aluminum Matrix Nano Al 2 O 3 Composites Produced via Friction Stir Deposition Using Different Initial Material Conditions. Materials 2022, 15, 2926. https://doi.org/10.3390/ ma15082926 Academic Editor: Emanuela Cerri Received: 17 March 2022 Accepted: 14 April 2022 Published: 17 April 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). materials Article The Additive Manufacturing of Aluminum Matrix Nano Al 2 O 3 Composites Produced via Friction Stir Deposition Using Different Initial Material Conditions Mohamed M. El-Sayed Seleman 1 , Sabbah Ataya 2 , Mohamed M. Z. Ahmed 3, * , Ahmed M. M. Hassan 4 , Fahamsyah H. Latief 2 , Khalil Hajlaoui 2 , Ahmed E. El-Nikhaily 4 and Mohamed I. A. Habba 4 1 Department of Metallurgical and Materials Engineering, Faculty of Petroleum and Mining Engineering, Suez University, Suez 43512, Egypt; mohamed.elnagar@suezuniv.edu.eg 2 Department of Mechanical Engineering, College of Engineering, Imam Mohammad Ibn Saud Islamic University, Riyadh 11432, Saudi Arabia; smataya@imamu.edu.sa (S.A.); fhlatief@imamu.edu.sa (F.H.L.); kmhajlaoui@imamu.edu.sa (K.H.) 3 Mechanical Engineering Department, College of Engineering at Al Kharj, Prince Sattam Bin Abdulaziz University, Al Kharj 16273, Saudi Arabia 4 Mechanical Department, Faculty of Technology and Education, Suez University, Suez 43518, Egypt; ahmed.mostafa@ind.suezuni.edu.eg (A.M.M.H.); ahmed.eassa@ind.suezuni.edu.eg (A.E.E.-N.); mohamed.atia@suezuniv.edu.eg (M.I.A.H.) * Correspondence: moh.ahmed@psau.edu.sa; Tel.: +966-115-888-273 Abstract: 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 Al 2 O 3 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 Al 2 O 3 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 Al 2 O 3 and AA2011-O/nano Al 2 O 3 composites, revealing well-bonded layers, grain refined microstructures, and homogeneously distributed Al 2 O 3 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. Keywords: additive manufacturing; friction stir deposition; AA2011; nanocomposites; temper conditions; hardness; compressive strength; wear resistance 1. Introduction Aluminum matrix ceramic composites (Al-MCCs) are of strong interest in the design of engineering parts in a vast number of industrial applications [13]. There are differ- ent uses for Al-MCCs in many sectors such as the aerospace, transportation, and marine industries. In general, Al-MCCs have superior properties, such as strength, hardness, and wear resistance, compared with aluminum alloys [47]. Different techniques have been used to introduce ceramic particles into aluminum matrix alloys: powder metallurgy (PM) [810], casting [1114], fusion-based additive manufacturing (FB-AM) [1517], and Materials 2022, 15, 2926. https://doi.org/10.3390/ma15082926 https://www.mdpi.com/journal/materials