Cu strengthened Al-Si-Cu semi-solid billet fabricated by liquid phase reaction sintering

作者：Liu, Wenchao; Sun, Yu^*; Deng, Cheng^*; Hu, Lianxi^*; Yuan, Shangjing; Shen, Jingyuan; Gao, Fei; Ba, Meiyi

来源：Materials Characterization, 2022, 188: 111925.

DOI：10.1016/j.matchar.2022.111925

• Liquid phase reaction sintering
• Cu nanoparticles
• Strengthening mechanism
• Mechanical property

A high-strength Al-6Si-6Cu semi-solid billet was prepared by liquid phase reaction sintering. Compared with the pure Al grains in the Al-6Si (wt%) semi-solid billet, Cu nanoparticles precipitated in Al grains of the Al-6Si-6Cu (wt%) semi-solid billet. The interface modified by geometrically necessary dislocations (GNDs) makes Cu nanoparticles show a strong pinning effect on dislocations. Under this pinning action, the Al-6Si-6Cu semi-solid billet possesses an outstanding strain-hardening rate, and its yield strength (YS) and ultimate strength (US) increased by 120% and 67.4%, reaching 220 MPa and 360 MPa respectively. The analysis of strengthening mechanism suggests that Orowan strengthening provided by Cu nanoparticles is the main strengthening mechanism of Al-6Si-6Cu semi-solid billet, which provides 83% of the total yield strength.

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