Zeng Tao, Zhou YaJun
College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China.
National Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, China.
Materials (Basel). 2019 Sep 27;12(19):3162. doi: 10.3390/ma12193162.
The effects of ultrasonic introduced by L-shaped sonotrodes made of high-temperature-resistant ceramic on the microstructure and macro-segregation of solidifying 15t AA2219 aluminum alloy ingots have been examined in the present study. The macroscopic morphology of the corrosion of the sonotrode has been observed. Grain refinement has been observed, the shape and size of the precipitated phase of the ingot were counted, and the degree of segregation along the transverse direction at 500 mm from the head of the ingot has been evaluated. The results reveal that the L-shaped ceramic ultrasonic introduction device can effectively avoid the erosion of high-temperature melt on the sonotrode and the heat radiation of the high-temperature heat flow to the transducer. Furthermore, the scanning electron microscope (SEM) and chemical composition detection results also indicate that the inter-dendritic micro-segregation of the equiaxed grains can be reduced, and the macro-segregation of the chemical composition of the ingot can be suppressed, and more homogeneous microstructures can be obtained when ultrasonic has been applied during solidification.
本研究考察了由耐高温陶瓷制成的L形超声换能器引入的超声对15t AA2219铝合金铸锭凝固组织和宏观偏析的影响。观察了超声换能器腐蚀的宏观形貌。观察到晶粒细化，统计了铸锭析出相的形状和尺寸，并评估了距铸锭头部500mm处横向的偏析程度。结果表明，L形陶瓷超声引入装置能有效避免高温熔体对超声换能器的侵蚀以及高温热流对换能器的热辐射。此外，扫描电子显微镜（SEM）和化学成分检测结果还表明，在凝固过程中施加超声时，可以减少等轴晶的枝晶间微观偏析，抑制铸锭化学成分的宏观偏析，获得更均匀的微观组织。
