固-液界面能各向异性对定向凝固Al-4.5wt.%Cu合金枝晶形态的影响

Influence of Solid-Liquid Interfacial Energy Anisotropy on Dendritic Morphology of Directionally Solidified Al-4.5wt.%Cu Alloy

采用高温度梯度定向凝固技术结合现代材料分析方法研究了固-液界面能各向异性对铝合金枝晶生长的影响。结果表明,当沿(100)晶面上不同晶向,在Al-4.5wt.%Cu合金中制备出轴向枝晶和退化枝晶;沿(111)晶面上不同晶向,制备出轴向海藻晶、倾斜海藻晶和退化海藻晶组织。通过构建界面能各向异性极图发现,不同枝晶的生长取向与晶面上各向异性强度最高方向一致。不仅拓展了金属合金凝固组织的研究范畴,而且对轻质金属材料铝合金的组织预测和控制有很好的指导作用。

In this article,by adopting the high temperature gradient directional solidification technology,the influence of interfacial energy anisotropy on the dendritic morphology of Al-4.5 wt.%Cu alloy was studied.The experimental results show that the axial dendrites and degenerate dendrites are identified in the(100)crystal plane with changing the orientation-dependent interfacial energy.In addition,different types of seaweeds,including the axial,tilted and degenerate seaweeds are observed in the(111)crystal plane with changing the crystal orientation.By analyzing the two-dimensional pole figures of the interfacial energy on different crystal planes,it is found that the dendrite is preferred to grow along the orientation of the maxima interfacial energy.These results will deepen our understanding on the dendrite evolution in real metallic alloys and broaden the field of solidification theory.