Al/CFRP叠层结构低频振动辅助钻削工艺研究

Low frequency vibration aided drilling technologyfor Al/CFRP laminated structure

在低频振动辅助Al/CFRP叠层结构配钻过程中,低频振动对复合材料的去除作用不明,难以同时保证Al和CFRP加工质量。针对这一问题,从理论角度对振动条件下刀具钻削过程中位置的变化规律进行了分析,并基于此讨论了低频振动对Al/CFRP叠层构件Al入口、CFRP出口和二者孔壁材料去除和加工质量的影响;进一步研究了低频振动工艺参数对加工质量的影响,搭建了包含低频振动刀柄的低频振动制孔实验平台,使用能够抑制CFRP出口损伤的刀具,进行了不同振幅下的低频振动辅助钻削实验。研究结果表明:低频振动能够有效地实现铝合金断屑,避免了长切屑对入口和铝合金孔壁的刮擦,提高了上层铝合金的加工质量;但低频振动的引入在一定程度上会增大钻削过程中的最大轴向力,同时过大的振幅会加剧中下层CFRP出口的撕裂损伤,并降低CFRP孔壁的加工质量。

Aiming at the problem that the unclear removal mechanism of CFRP could not ensure machining quality of Al and CFRP at the same time during low-frequency vibration-assisted drilling process of Al/CFRP laminated structure,the tool path during vibration-assisted drilling was analyzed by theoretic method.Based on this,the effect of low frequency vibration on material removal and processing quality at Al entrance,CFRP exit and hole wall of the laminated structure was revealed.The influence of low-frequency vibration parameters was further studied,a drilling platform including low-frequency vibration tool holder was built,based on which low-frequency vibration-assisted drilling experiments with special designed tools for CFRP at different amplitudes were conducted.The results indicate that low-frequency vibration can effectively achieve aluminum alloy chip breaking,avoiding scratching of long chips and improving the processing quality of Al part.The introduction of low-frequency vibration can increase the maximum axial force and excessive amplitude can exacerbate tear damage of CFRP at the exit and reduce the quality of drilled hole wall.