Softening due to severe strength degradation is inevitable in metallic materials at elevated temperatures especially at T > 0.5T_m. For instance, at 300 °C, most Al alloys exhibit a low yield strength of only several tens of MPa, merely 10~40 % of that at room temperature. The popular pathways to enhance high-temperature strength have been realized by integrating second-phase reinforcements, such as micro-/nanosized intermetallics, precipitates or ceramic particles in the alloy matrix [1]. In this regard, the most efforts have been made to maintain high volume fraction of the evenly-distributed second-phase particles, while improving their coarsening-resistance. The recent thriving additive manufacturing (AM) technology has shown not only its massive industrial application prospects in rapid prototyping of complex-shaped metallic component with unprecedented freedom, but also highly potential to achieve novel metastable and ultrafine microstructures exploiting its inherent rapid solidification process. In particular, a specific 3D ultrafine cellular-like architecture, consisting of one phase/domain in cells enclosed by the other phase/domain as 3D interconnected network as cell boundaries, has been extensively reported in AM Al [2], Fe, Cu, and other alloys.

In this work, we proposed a new architecture design strategy for developing high-strength and heat-resistant Al alloys using AM. We demonstrated that a thermally stable nano eutectic cellular network can be engineered in a novel near-eutectic AlLaScZr alloy during laser powder bed fusion (LPBF) process. The LPBFed alloy exhibits exceptional strength above ~0.6 T_m of Al, where the tensile yield strength reaches ~250 MPa at 300 °C, two to five folds of the conventionally fabricated Al alloys [3].


References: Yu Ma, Han Chen, Mingxing Zhang, Ahmed Addad, Yi Kong, M.B. Lezaack, Weiming Gan, Zhe Chen, Gang Ji, Acta Materialia, 242 (2023) 118470 Chengyi Dan, Yuchi Cui, Yi Wu, Zhe Chen, Hui Liu, Gang Ji, Yakai Xiao, Han Chen, Mingliang Wang, Jun Liu, Lei Wang, Yang Li, Ahmed Addad, Ying Zhou, Siming Ma, Qiwei Shi, Haowei Wang, Jian Lu, Nature Materials 22 (2023) 1182-1188 Siming Ma, Zhe Chen, Haixing Fang, Gang Ji, Mingliang Wang, Yuchi Cui, Yang Li, Sheng-Yi Zhong, Han Chen, Yi Wu, Ying Zhou, Shixin Nie, and Jian Lu, Nature Communications, 16 (2025) 11361
 

additive manufacturing,aluminum