Effect of eutectic silicon on crack formation and propagation of Al-20%Si alloy by in-situ observation

doi:10.13251/j.issn.0254-6051.2020.06.040

Abstract

Abstract: Crack formation and propagation of Al-20%Si alloy were observed in-situ by using confocal laser scanning microscope, the effect of eutectic silicon on crack formation location and crack propagation mode of Al-20%Si alloy were studied. The results show that with the increase of solution temperature, the eutectic silicon phase in the Al-20%Si alloy changes into particles. During the tensile process, cracks easily occur at the needle-shaped eutectic silicon of the as-cast Al-20%Si alloy, and the cracks mainly propagate between the eutectic silicon. After solution at 560 ℃ for 6 h and aging at 190 ℃ for 10 h, the acicular eutectic silicon in the microstructure of the alloy transforms completely into granular silicon, the propagation rate is decreased, and the tensile strength and plasticity of the alloy are improved obviously.

Key words: hypereutectic aluminum silicon alloy, eutectic silicon, crack, in-situ observation

CLC Number:

TG146.2

He Shaofu, Li Qingchun, Zhao Shuai, Chen Shuying, Chang Guowei. Effect of eutectic silicon on crack formation and propagation of Al-20%Si alloy by in-situ observation[J]. Heat Treatment of Metals, 2020, 45(6): 194-196.

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