半连续铸造制备7075／6009铝合金梯度复合材料

Preparation of 7075/6009 Gradient Aluminum Matrix Composites by Semi-continuous Casting

采用双流浇注半连续铸造技术制备了7075/6009铝合金梯度复合材料。分析了合金内层、过渡层、外层的宏观和微观组织形态以及成分分布,并测量了铸件径向的洛氏硬度。结果表明,通过合理控制铸造参数,可以获得具有成分梯度和硬度梯度分布的7075/6009复合材料;梯度复合材料在凝固过程中,内、外合金熔体以紊流复合;过渡复合层的宽度主要受到内、外熔体的浇注温度、节流片孔径大小以及内导管插入结晶器深度的影响。

The 7075/6009 gradient aluminum alloy composites have been prepared by double-stream-pouring semi-continuous casting.The macro-structure and micro-structure and composition distribution in the internal,transitional and external layers of the ingot have been analyzed,and the Rockwell hardness in radial of the ingot has been measured also.The results indicate that the 7075/6009 aluminum alloy composites with gradient distribution in composition and hardness can be successfully prepared by optimizing processing parameters.The turbulent flows is dominant in internal and external alloy melt solidification process.The width of the transitional region is dependent on the pouring temperature of internal and external alloy melt,aperture of the throttle bore and the depth of the nozzle submerged in the mold.