Effects of cooling rate and Sc content on Al3CuNi phase in cast heat-resistant Al–Si–Cu–Ni alloys
Al–Si–Cu–Ni alloys are key foundational materials for manufacturing heat-resistant lightweight components in aerospace and other fields, and the Al3CuNi is an important solidified phase in such alloys, which has a significant impact on the grain boundary stability and the high-temperature mechanical...
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| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-09-01
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| Series: | Journal of Materials Research and Technology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785425019866 |
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| Summary: | Al–Si–Cu–Ni alloys are key foundational materials for manufacturing heat-resistant lightweight components in aerospace and other fields, and the Al3CuNi is an important solidified phase in such alloys, which has a significant impact on the grain boundary stability and the high-temperature mechanical properties of the alloy. In this work, the influence of Sc content and cooling rate on the Al3CuNi phase in the Al–Si–Cu–Ni alloy is explored. The results show that with the increase of Sc content from 0.2 wt% to 0.4 wt%, the new phases of Sc3Si5, Sc2Ni7, AlCuNiSc and AlSiCuNiSc are solidified. As the cooling rate increased from 1.6 °C/s to 20 °C/s, the Al3CuNi phase changed from a typical regular eutectic lamella to an irregular form such as needle and block, and the submicron and nanoscale AlCuNiSc and AlSiCuNiSc phases are formed in the as-cast α-Al matrix. It is demonstrated that the bulk AlCuNiSc and AlSiCuNiSc phases are formed by peritectic reaction with Sc2Ni7 and Sc3Si5 as cores, respectively. In addition, rapid solidification can drive the solid/liquid interface to engulf submicron and nanoscale AlSiCuNiSc and AlCuNiSc and distribute them in α-Al matrix. High-temperature tensile tests show that compared to the needle-like and elongated morphologies of Al3CuNi phases, the well-developed eutectic lamellae, especially when multiple Al3CuNi eutectic colonies form an interconnected network structure, has a more pronounced strengthening effect on the alloy. |
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| ISSN: | 2238-7854 |