Understanding the influence of high-strength submicron precipitate on the fracture performance of additively-manufactured aluminum alloy

作者：Li Cao, Renyi Lu, Zheng Dou, Min Zheng, Han Xiao, Yu Hao, Li Zhang, Jinfang Zhang, Bin Liu, Xiaofeng Li · 发表于：International Journal of Plasticity · 年份：2025 · DOI：10.1016/j.ijplas.2025.104306 · 被引用次数：48 · 研究领域：Additive Manufacturing Materials and Processes、Additive Manufacturing and 3D Printing Technologies、Titanium Alloys Microstructure and Properties

• The formation process of submicron precipitate and its influence mechanism on the mechanical performance are first revealed in the Al-Cu-Ni alloy during additive manufacturing-heat treatment. • The microstructure evolution from manufacturing to fracture is analyzed systematically, and the coordinated strength-ductility performance is achieved by microstructure regulation. • The in-situ dislocation motion and crack propagation are newly studied in Al-Cu-Ni alloy to provide direct evidences for its fracture failure mechanism. • Novel findings are grained that the submicron grain-boundary Al 7 Cu 4 Ni precipitate and dislocation entanglement present the obstruction effect on the intergranular and intragranular cracks, respectively. • Combining ex-situ TEM and DFT calculation reveals the intact and stable structure of the Al 7 Cu 4 Ni precipitate with submicron dimension and high bonding strength. The formation of intermetallic compound has been widely considered as an effective strengthening approach in Al alloy. Its precipitate dimension is a key factor influencing the mechanical performance. Except for the pinning effect of nanosized precipitate, the contribution of submicron precipitate is also nonnegligible. Therefore, establishing the mechanism framework for the relationship of manufacturing process-precipitate structure-fracture performance is of great significance, which is essential and foundational for optimizing the practical service performance of alloys parts. Here...