Peng Hao, Li Ruiqing, Li Xiaoqian, Ding Shan, Chang Mengjun, Liao Liqing, Zhang Yun, Chen Pinghu
College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China.
Light Alloy Research Institute, State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410012, China.
Materials (Basel). 2019 Sep 3;12(17):2828. doi: 10.3390/ma12172828.
The structure and composition of large-scale Al-Cu alloy ingots are inhomogeneous, and the segregation of (especially) elemental Cu negatively affects the uniformity and stability of the subsequent components. In this work, four ultrasonic generators were used to manipulate solidification/microstructures of cylindrical Al-Cu ingots (1250 mm in diameter; 3500 mm in length). The influence of ultrasonic configuration on both solidification microstructures and solute macrosegregation was investigated by changing the position parameters of generators for a fixed power. The results revealed that when the ultrasound is applied close to the center (I) from the 1/2 radius (II), the grain structure of the center undergoes significant refinement, degree of positive segregation in the center can be reduced, segregation index decreased from 0.2 to 0.15, and range of positive segregation in the center decreased from 200 to 150 mm. The segregation of elemental Cu was weakened by the combined effects of the ultrasound on the flow, heat transfer, and grain movement.
大型铝铜合金铸锭的结构和成分不均匀，（特别是）元素铜的偏析会对后续部件的均匀性和稳定性产生负面影响。在这项工作中，使用了四个超声波发生器来控制圆柱形铝铜铸锭（直径1250毫米；长度3500毫米）的凝固/微观结构。通过在固定功率下改变发生器的位置参数，研究了超声配置对凝固微观结构和溶质宏观偏析的影响。结果表明，当从1/2半径（II）处靠近中心（I）施加超声波时，中心的晶粒结构会显著细化，中心的正偏析程度会降低，偏析指数从0.2降至0.15，中心正偏析范围从200毫米降至150毫米。超声波对流动、传热和晶粒运动的综合作用减弱了元素铜的偏析。
