Pre-oxidization of SiCp on interfacial structure and mechanical properties in 55 vol% SiCp/6061Al composites prepared by semi-solid hot isostatic pressing
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Pre-oxidization of SiCp on interfacial structure and mechanical properties in 55 vol% SiCp/6061Al composites prepared by semi-solid hot isostatic pressing
Pre-oxidization of SiCp on interfacial structure and mechanical properties in 55 vol% SiCp/6061Al composites prepared by semi-solid hot isostatic pressing
Cheng, K., Cao, Y., Hu, Z., Zhang, M., Shi, L., Tian, C., Cai, C., & Shi, Y. (2026). Pre-oxidization of SiCp on interfacial structure and mechanical properties in 55 vol% SiCp/6061Al composites prepared by semi-solid hot isostatic pressing. Journal of Alloys and Compounds, 1057, 186887. https://doi.org/10.1016/j.jallcom.2026.186887
Abstract:
Hot isostatic pressing (HIP) enables near-net-shape fabrication of high-volume-fraction SiCp/Al composite parts, for which interfacial regulation at the SiCp/Al interface is critical to mechanical performance. SiCp pre-oxidization is a widely used approach that forms a surface SiO2 layer, which reacts with the Al alloy during HIP to generate an interfacial phase that promotes efficient load transfer in the composites. In this study, the effects of SiCp pre-oxidization on the interfacial structure and mechanical properties of 55 vol% SiCp/6061Al composites via semi-solid HIP were investigated. SiCp was pre-oxidized at 1100 °C for different times to adjust the surface SiO2 thickness, which determined the morphology and thickness of the MgAl2O4 interfacial phase formed between SiCp and the 6061Al matrix. As the SiCp pre-oxidization time increased from 0 to 4 h, the interface evolved from a reaction-free SiC-Al interface (0 h) to a ∼180 nm thin interface (2 h) and eventually to a ∼300–900 nm much thicker interface (4 h). The best tensile performance was obtained at 1–2 h, and the 2 h sample reached a UTS of 372.2 MPa, 10.2 % higher than the 0 h sample (337.8 MPa), whereas the 4 h sample exhibited a reduced UTS of 319.7 MPa. The MgAl2O4 interlayer transformed the highly mismatched direct SiC-Al interface (mismatch about 25.6 % for the observed orientation relationship) into a segmented transition interface, reducing mismatches to 7.69 % (SiC-MgAl2O4) and 21.07 % (MgAl2O4-Al), which improved load transfer and mitigated stress localization. Excessive oxidization produced a brittle, non-dense layer prone to cracking and degraded interfacial integrity. The findings establish a process-structure-property relationship that guides the semi-solid HIP formation of SiCp/Al composites with high mechanical performance through modified interfacial structure.
License type:
Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
Funding Info:
The work was financially supported by the National MCF Energy R&D Program (No. 2022YFE03210400)
The Joint Funds of the National Natural Science Foundation of China (No. U22A202494).