An Al-12Si/ZnS powder inoculant for eutectic silicon in Al-12Si alloy

• Key Words:AL-SI ALLOYSCHEMICAL BATH DEPOSITIONMECHANICAL-PROPERTIES
• Abstract:To obtain high-performance Al-Si-based cast alloys,refinement and modification of Si phases are required.An Al-12Si/ZnS powder inoculant was designed and fabricated using a chemical bath deposition method.The efficiency of the inoculant for modifying the eutectic Si phase in as-cast Al-12Si alloy was studied.Results show that Al-12Si/ZnS powder can significantly refine the eutectic Si in Al-Si cast alloys.The best refinement effect for eutectic Si is achieved with 17.5wt.% Al-12Si/ZnS powder.Coarse long needle-shaped eutectic Si with a length of 18 μm was modified into approximately spherical shape with a diameter of 6.53 μm,which is evenly distributed throughout the alloy.The E2EM model calculation indicates that the inter-plane misfit (F_p) and inter-atomic spacing misfit (F_r) between ZnS and Si are all less than 0.5%,which confirms that ZnS is a potential nucleation site for Si phase.The hardness,tensile strength,and elongation of Al-12Si alloys modified with 17.5% Al-12Si/ZnS powder increase 6.30%,16.18% and 55.45%,respectively,compared to the unmodified Al-12Si alloy.The fracture behavior of the alloy with 17.5wt.% Al-12Si/ZnS powder is dominated by transgranular fracture supplemented by intergranular fracture.
• Volume:v.19
• Issue:02
• Translation or Not:no