Al/Zn双金属复合板的界面研究

Interface of Al/Zn Bimetal Composite Plate

采用复合铸造制备了A356/Zn双金属复合板。通过改变两种合金的浇注顺序和A356铝合金浇注温度来改变复合板界面组织和过渡区厚度。通过对复合界面进行SEM+EDS分析,研究了A356/Zn双金属复合板界面组织的形成机制。结果表明,当A356铝合金浇注温度为660℃时,界面实现了良好的冶金结合,形成了发达的树枝晶,过渡区厚度约为2mm,结合界面根据生成相的不同可以分为3个区域;当A356铝合金的浇注温度为620℃时,中间区域的树枝晶有明显减小甚至消失,过渡区的厚度减小到约1mm。

A356/Zn bimetal composite plate was prepared by double liquid composite casting.The interfacial microstructure and interface cross sectional height of the composite plate were adjusted by changing the pouring sequence of the two alloys and the pouring temperature of A356 aluminum alloy.The microstructure and mechanism of composite layer formation at the A356/Zn interface were evaluated by scanning electron microscope（SEM）and energy dispersive spectrometer（EDS）.The results reveal that the interface of A356/Zn bimetal composite plate presents desirable metallurgical bonding with A356 melt at660 ℃,where a well-developed dendrite can be formed with interface cross sectional height of about 2 mm.The interface can be divided into three regions based on the generation phase.When the pouring temperature of A356 aluminum alloy is 620℃,the dendrites in the composite interface are reduced obviously or even absent with the width of composite interface decreased to about 1 mm.