To meet the need of aluminum melt degassing, a hollow exponential ultrasonic horn was proposed. The numerical analysis showed that the amplification factor and shape factor of the horn will increase with the increasing central hole diameter. When the hole diameter is less than 20 mm, they increase slowly while rapidly once the hole diameter excessed 35 mm. The modal analysis and experiments indicated that the resonance frequencies of all the horns are very close to the set frequency, and the errors are less than 3%. Although the displacement amplitude differences are both more than 20 µm, the central hole horn is larger, which is consistent with the result of modal analysis. A simple aluminum melt degassing system employing the proposed hollow horn and rotary impeller was used to experiment on ZL101A aluminum melt, and the results indicated the more satisfactory degassing efficiency can be got by using the appropriate parameters.

为了满足铝熔体脱气的需要，提出了一种空心指数式超声波变幅杆。数值分析表明，喇叭的放大系数和形状系数会随着中心孔直径的增加而增加。当孔直径小于20毫米时，一旦孔直径超过35毫米，它们就会缓慢而迅速地增加。模态分析和实验表明，所有喇叭的共振频率都非常接近设定频率，误差小于3％。尽管位移幅度差都大于20 µm，但中心孔角更大，这与模态分析的结果一致。使用建议的空心喇叭和旋转叶轮的简单铝熔体脱气系统用于ZL101A铝熔体的实验，