Enhanced Strength–Ductility Synergy in Submerged Friction Stir Processing ER2319 Alloy Manufactured by Wire-Arc Additive Manufacturing via Creating Ultrafine Microstructure

• Published in: Acta metallurgica sinica : English letters Vol. 37; no. 5; pp. 793 - 807
• Main Authors: Hu, Jinpeng, Sun, Tao, Cao, Fujun, Shen, Yifu, Yang, Zhiyuan, Guo, Chan
• Format: Journal Article
• Language: English
• Published: Beijing The Chinese Society for Metals 01.05.2024; Springer Nature B.V
• Subjects: Additive manufacturing; Aluminum base alloys; Characterization and Evaluation of Materials; Chemistry and Materials Science; Cooling; Cooling rate; Corrosion and Coatings; Ductility; Friction stir processing; Friction stir welding; Grain growth; Grain refinement; Grain size; High temperature; Intermetallic compounds; Low temperature; Machining; Manufacturing; Materials Science; Mechanical properties; Metallic Materials; Microstructure; Nanotechnology; Organometallic Chemistry; Residual stress; Solids; Spectroscopy/Spectrometry; Thermal cycling; Tribology; Ultimate tensile strength; Ultrafines; Wire; Wire-arc additive manufacturing; Al–Cu alloy; Submerged friction stir processing; Residual stress; Strengthening and toughening mechanism; Ultrafine grained microstructure
• ISSN: 1006-7191; 2194-1289
• DOI: 10.1007/s40195-023-01655-z

Submerged friction stir processing (SFSP) with flowing water was employed to alleviate the porosities and coarse-grained structure introduced by wire-arc manufacturing. As a result, uniform and ultrafine grained (UFG) structure with average grain size of 0.83 μm was achieved with the help of sharply reduced heat input and holding time at elevated temperature. The optimized UFG structure enabled a superior combination of strength and ductility with high ultimate tensile strength and elongation of 273.17 MPa and 15.39%. Specifically, grain refinement strengthening and decentralized θ (Al 2 Cu) phase in the sample subjected to SFSP made great contributions to the enhanced strength. In addition, the decrease in residual stresses and removal of pores substantially enhance the ductility. High rates of cooling and low temperature cycling, which are facilitated by the water-cooling environment throughout the machining process, are vital in obtaining superior microstructures. This work provides a new method for developing a uniform and UFG structure with excellent mechanical properties.