驻波超声/高频磁场在非接触可控熔融与阶梯凝固过程中的混合作用机理及控制方法研究

Study on coupling theory and control method of standing wave ultrasonic and high-frequency electromagnetic field in the process of containerless controllable melt and stage solidification In the project, research of containerless processing on Study on coupling theory and control method of standing wave ultrasonic and high-frequency electromagnetic field in the process of containerless controllable melt and stage solidification of standing wave ultrasonic and high-frequency electromagnetic field in the process of containerless controllable melt and stage solidification is carried out and relationships of hybrid levitation with controllable melt and stage solidification is studied, and control methods of this phenomenon will be deeply studied. The solid object is levitated and oriented contactlessly in the coupled field by mingling ultrasound standing wave field and high-frequency electromagnetic field in gravity field. At the same time, the levitated object is induced by the high-frequency electromagnetic field and heated to melt contactly, with temprature controlled. Meanwhile, through feedback controll of ultrasonic suspension force and high-frequency electromagnetic field suspension force in the solidification process, the induction heating power of high-frequency electromagnetic field is changed step by step and the molten object is phase solidified, thus, containerless processing is totally achieved. What we are going to do includes: set up kinetic model of the suspended object acted by ultrasound standing wave and high-frequency electromagnetic field, and obtain physical, structural and control factors which influence characteristic of the levitated object; also, analyse relationship of melting process, with temperature controlled, and hybrid levitstion; in addition, research the movement phenonenon and control methods of the suspended moten object on which when the effect is transformed from coupled fields with ultrasonic standing wave field and high-frequency electromagnetic field into independent ultrasonic standing wave field.

项目研究在无容器处理过程中，驻波超声与高频磁场在非接触可控熔融与阶梯凝固过程中的混合作用机理，研究混合悬浮与可控熔融和阶梯凝固之间的关系及实现方法。通过驻波超声场及高频磁场在重力场中的混合叠加，实现高频感应熔融物体在混合叠加场中的非接触悬浮支撑定位，并且通过这种高频磁场感应加热，实现非接触温度可控熔融；同时其凝固过程中通过反馈控制超声悬浮力和高频磁场悬浮力，逐级改变高频磁场的感应加热功率，对熔融物质阶梯凝固，实现完全意义上的无容器处理。具体包括：建立超声驻波和高频磁场混合悬浮物体的动力学模型，获得物理学、空间机构及控制学因素对超声场与高频磁场混合作用下的熔融物体的影响特性；研究可控温度熔融过程与混合悬浮之间的关系；研究阶梯凝固阶段超声波悬浮与高频磁悬浮混合悬浮之间相互转化关系及控制方法。

本项目提出一种在非接触状态下，熔融温度可控以及阶梯凝固过程可控的新型无容器处理方法。该方法采用驻波超声与高频磁场混合悬浮的方式实现悬浮物体的非接触温度可控熔融，并且在凝固过程中通过对二者悬浮力比例的控制，实现高频熔融物质的阶梯凝固。通过驻波超声场及高频磁场在重力场中的混合叠加，实现高频感应熔融物体在混合叠加场中的非接触悬浮支撑定位，并且通过这种高频磁场的感应加热，实现非接触温度可控熔融；同时其凝固过程中通过反馈控制超声悬浮力和高频磁场悬浮力，逐级改变高频磁场的感应加热功率，对熔融物质阶梯凝固，实现完全意义上的无容器处理。本项目研究这种混合悬浮状态下，温度可控熔融与阶梯凝固阶段的混合作用机理及控制方法。.通过对声压和悬浮的分析，研究了谐振管对声驻波悬浮装置(以下简称声悬浮装置)性能的影响。利用ANSYS和MATLAB对四种无共振管和不同半径R共振管的声学悬浮装置进行了受力分析。引入共振管可以增强或削弱声学悬浮装置的悬浮强度，这取决于谐振管的半 径。特别是，当共振管半径略大于反射器端面尺寸时，悬浮力得到了最大程度的改善。通过引入R=1.023λ的共振管，最大限度地提高了声学悬浮装置的稳定性。研制了带有凹端面型发射体和反射器的声学悬浮装置的实验平台和悬浮力测量系统。并进行了悬浮物和液滴的试验。结果表明，Ф6.5mm钢球在谐振管半径为1.023λ时容易悬浮，而Ф5.5mm钢球则容易悬浮。 当共振管半径为1.251λ时，不存在悬浮现象。当应用R=1.251λ的共振管时，原无共振管的声悬浮装置的悬浮能力减弱。计算结果与ANSYS仿真结果吻合较好。共振管R=1.023λ的液滴悬浮时间比没有共振管的液滴悬浮时间长。这一结果也得到了MATLAB仿真结果的支持。因此，通过引入合适半径的谐振管，可以提高声学悬浮装置的性能。.本项目研究过程中发表论文12篇，其中SCI论文7篇，EI论文1篇，申请专利6项，其中发明专利3项，实用新型专利3项，培养了硕士研究生7人，其中硕士研究生4人，博士研究生3 人。