ABSTRACT

In this work, OM, SEM/EDS, XRD, DSC, and tensile test were used to study the effect on mechanical and thermodynamic properties of Al-10Si-0.8Fe alloys with Al-Ti-C (0.5 wt.%) and xCe (viz. 0.2, 0.4, 0.6 and 0.8 wt.%) compound addition. After adding compound additives to Al-10Si-0.8Fe, the average size of SDAS decreased and the mechanical properties increased. When Ce is 0.6 wt.%, The smallest SDAS size and the best mechanical properties were obtained, then the melting range and enthalpy of melting also reached the minimum. Al-Ti-C can form submicron TiC in the melt, which refines the grains, and adding Ce can form Ce₅Si₃ to round the needle-like Fe-rich phase and reduce the adverse effect, the composite additions of them synergistically improve the properties of Al-10Si-0.8Fe alloy. But excessive Ce could aggregate Ti and Fe-rich phases, then coarse impurity particles could form in the melt, leading to modification failure and performance deterioration.

摘要

在这项工作中，OM、SEM/EDS、XRD、DSC 和拉伸试验用于研究 Al-Ti-C (0.5 wt.%) 和 xCe 对 Al-10Si-0.8Fe 合金的机械和热力学性能的影响(即 0.2、0.4、0.6 和 0.8 wt.%) 化合物添加。在Al-10Si-0.8Fe中加入复合添加剂后，SDAS的平均尺寸减小，力学性能提高。当Ce为0.6 wt.%时，SDAS尺寸最小，力学性能最好，熔程和熔化焓也达到最小值。Al-Ti-C在熔体中可形成亚微米TiC，细化晶粒，加入Ce可形成Ce ₅ Si ₃为圆化针状富铁相并减少不利影响，它们的复合添加协同改善了Al-10Si-0.8Fe合金的性能。但过量的Ce会使富Ti和Fe相聚集，然后在熔体中形成粗大的杂质颗粒，导致改性失败和性能下降。