| Title |
Effect of Sr addition on the Microstructure and Mechanical Properties of Al-Si/Cu Bimetals |
| Authors |
임하윤(Ha-Yoon Lim) ; 김병주(Byung-Joo Kim) ; 천현석(Hyun-Seok Cheon) ; 김수현(Su-Hyeon Kim) ; 이욱진(Wook-Jin Lee) |
| DOI |
https://doi.org/10.3365/KJMM.2026.64.1.1 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Al-Si/Cu bimetal; Sr addition; Compound casting; Intermetallic compound; Multi-phase layer; Eutectic structure |
| Abstract |
This study examined the influence of Sr addition on the microstructure and mechanical
properties of Al?Si/Cu bimetals fabricated by compound casting. Particular emphasis was placed on the
multi-phase layer that formed beyond the intermetallic compound layer at the Al?Si/Cu interface. While
most previous research has primarily highlighted how the thickness of the intermetallic compound layer
affected mechanical performance, the present work focused on modification of eutectic phases in the multiphase
region and their impact on overall material behavior. The addition of Sr to the Al-Si alloy did not
produce major changes in the intermetallic compound layer itself. However, it significantly refined and
homogenized the eutectic phases in the multi-phase region, leading to a finer and more uniformly
distributed microstructure. Compression testing demonstrated that the bimetals containing Sr exhibited
both higher strength and greater elongation compared to those without Sr. Furthermore, a clear transition
in fracture behavior was observed: cracks that used to propagate rapidly along brittle intermetallic
compound phases in the Sr-free bimetals were delayed and gradually deflected through the interfaces in
the Sr-modified bimetals. Overall, the results demonstrate that controlling eutectic phases in the multiphase
layer, combined with compound casting, provides an effective strategy to optimize microstructure and
improve the mechanical reliability of the Al?Si/Cu bimetals. |