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在半连续铸造过程中施加超声,成功制备了Φ1250 mm 2219铝合金铸锭.利用光学显微镜、扫描电镜、能谱仪及直读光谱仪等仪器对铸锭的组织与成分分布进行检测与分析,探究超声对铸锭组织与偏析的内在作用机制.研究结果表明:超声振动引起的空化和声流效应能明显均匀组织结构,细化晶粒,尤其是心部晶粒细化率达到39.6%.超声促进铸锭晶间第二相呈枝丫状断续分布,晶内析出物点状弥散分布.同时,超声有效减小近表面负偏析,降低边部与心部之间的溶质浓度差异,弱化整个横截面的浓度波动,从而改善宏观偏析.
During the process of semi-continuous casting, the ingot of Φ1250 mm 2219 aluminum alloy was successfully prepared, and the microstructure and composition distribution of ingot were detected and analyzed by means of optical microscope, scanning electron microscope, energy dispersive spectrometer and direct reading spectrometer The internal mechanism of ultrasonic wave on the microstructure and segregation of ingot is studied.The results show that cavitation and acoustic flow effect caused by ultrasonic vibration can obviously uniform structure and grain refinement, especially the grain refinement rate reaches 39.6%. Ultrasound promotes the discontinuous distribution of the second phase between the ingots and the spot-like dispersion of precipitates in the ingot, meanwhile, ultrasound effectively reduces the near-surface negative segregation, reduces the difference of solute concentration between the edge and the heart, and weakens The concentration of the entire cross section fluctuates, thereby improving macrosegregation.