Remarkably promoting strength-ductility synergy in thin-wall Al-Si die castings with a lower content of in-situ TiB2 particles

The development of high-performance thin-wall non-heat treatable Al-Si die castings (NHT-DCs) in automotive industry is urgently demanded. However, the traditional design mentality by alloying has reached its limit with inevitable strength-ductility trade-off. Herein, we proposed a novel strategy in...

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Bibliographic Details
Main Authors: Hongyi Zhu, Zeyu Bian, Chengyang Hu, Cunjuan Xia, Siming Ma, Yihao Wang, Mingliang Wang, Huawei Zhang, Zhe Chen, Haowei Wang
Format: Article
Language:English
Published: Elsevier 2025-09-01
Series:Materials & Design
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Online Access:http://www.sciencedirect.com/science/article/pii/S0264127525009475
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Summary:The development of high-performance thin-wall non-heat treatable Al-Si die castings (NHT-DCs) in automotive industry is urgently demanded. However, the traditional design mentality by alloying has reached its limit with inevitable strength-ductility trade-off. Herein, we proposed a novel strategy in promoting strength-ductility synergy by thin-wall TiB2/Al-Si NHT-DCs. Herein, insitu TiB2 particles were greatly dispersed owing to the severe shear and rapid solidification effects during DC process, exhibiting the more effective strengthening effect. Then, a prominent fine αII-AlFeMnSi phase was experimentally identified with the small interfacial coherency with TiB2, and interfacial characteristics were justified by first-principles calculations thermodynamically. Meanwhile, the edge-to-edge model suggested that Si solute expected to be enriched into band region was excessively consumed by the induced αII-AlFeMnSi and eutectic Si in the central region, hereby improving the microstructural homogeneity of DCs. Accordingly, the microstructure-based representative volume element simulations illustrated that the ductility was greatly enhanced by this microstructural homogeneity. Compared to alloy counterpart, the yield strength and elongation of 0.3 wt%TiB2/Al-Si composite presented the substantial increment of ∼15 % and 9.2 %, respectively. Finally, this work attained a notably high utilization of TiB2 particles in high-performance NHT-DC Al-Si composite with superior mechanical properties, holding significant industrial feasibility and showing promising application prospects.
ISSN:0264-1275