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目的：基于纵-扭复合振动超声加工和超声深滚加工提出了纵-扭复合振动超声深滚加工工艺，研究各深滚工艺参数对工件表面强度的影响，以验证二维超声振动加工技术在表面强化技术领域的应用效果。方法采用单因素试验法对6061-T651铝合金轴件分别进行纵-扭复合振动超声深滚与常规深滚加工试验，然后用MH-5数显硬度计测试每组参数下的表面显微硬度，研究静压力、工件转速和进给量对工件表面显微硬度的影响，并将两种试验结果进行对比。结果在设定工艺参数内，纵-扭复合振动超声深滚工艺所获得的表面显微硬度均高于同等加工条件下常规深滚工艺。纵-扭复合振动超声深滚加工时，表面显微硬度随静压力和工件转速的增大先增大后减小，随进给量的增大先减小后增大再减小；常规深滚加工时，表面显微硬度与静压力近似呈线性关系，且随工件转速的增大先增大后减小，随进给量的增大一直减小。结论纵-扭复合振动超声深滚加工工艺能更有效地实现6061-T651铝合金的表面强化处理。

ABSTRACT:Objective To propose ultrasonic deep rolling with longitudinal-torsional vibration ( UDR-LTV) based on ultrasonic machining with longitudinal-torsional vibration and ultrasonic deep rolling, and to study the effects of processing parameters on sur-face strengthening, so as to verify the application effect of the two-dimensional ultrasonic vibration machining technology in the field of surface strengthening technology. Methods Conventional deep rolling ( CDR) and UDR-LTV were applied using the single factor experiment to process aluminum alloy 6061-T651 respectively, then the surface micro-hardness was tested by each set of parameters with the MH-5 digital hardness tester to investigate the influence of static pressure, rotate-speed and feed amount on the surface mi-cro-hardness. The results of the two processing ways in the experiment were compared. Results Within the set parameters, the sur-face micro-hardness obtained by UDR-LTV was larger than that of CDR under the same processing conditions. The surface micro-hardness increased at first then decreased with the increase of static pressure and rotate-speed, and decreased at first then increased and decreased at last with the increase of feed amount by UDR-LTV. The surface micro-hardness and static pressure showed an ap-proximate linear relationship, and the surface micro-hardness increased at first then decreased with the increase of rotate-speed, and reduced all along with the increase of feed amount by CDR. Conclusion It is proved that aluminum alloy 6061-T651 may be more effectively strengthened when treated by UDR-LTV.