Synergistic enhancement of mechanical strength and thermal conductivity in a novel Al-Mg-Si-Zr-Ce alloy fabricated by powder bed fusion-laser beam

作者：Li Zhang, Zhengzhen Lu, Li Cao, Jianhong Wang, Jinfang Zhang, Xiaohui Yang, Yuankui Cao, Bin Liu, Xiaofeng Li · 发表于：Materials & Design · 年份：2025 · DOI：10.1016/j.matdes.2025.114305 · 被引用次数：47 · 研究领域：Additive Manufacturing Materials and Processes、High Entropy Alloys Studies、Intermetallics and Advanced Alloy Properties

• A nearly full dense Al-Mg-Si-Zr-Ce alloy was fabricated via 1 wt% ZrH 2 addition during PBF-LB. • T6 simultaneously enhanced the strength and thermal conductivity of the PBF-LB prepared Al-Mg-Si-Zr-Ce alloy. • The synergistic improvement is primarily attributed to the bimodal grain structure resulting from T6 treatment. To address the growing demand for lightweight thermal management solutions, this study presents a novel Al-Mg-Si-Zr-Ce alloy designed for powder bed fusion-laser beam (PBF-LB), achieving exceptional synergy between mechanical strength and thermal conductivity through composition design (including Zr microalloying) and systematic process optimization. By incorporating 1 wt% ZrH 2 during PBF-LB processing, a high relative density of 99.49% was achieved. The original coarse columnar-grained structure of the base alloy was transformed into a bimodal microstructure of equiaxed grains and refined columnar grains for the Zr-modified alloy. Microstructural analysis reveals that this transformation originates from two key factors: the formation of primary Al 3 Zr particles acting as effective heterogeneous nucleation sites, and the preferential precipitation of Mg 2 Si phases along short columnar grain boundaries. Post-T6 treatment resulted in remarkable property improvements, with yield strength increasing by 50.5% and thermal conductivity elevating by 63.3%. The mechanical strengthening derives from synergistic grain refinement effects and precipitation hardening, ...