低频振动钻削CFRP/钛合金叠层材料试验研究

Experimental Study of Low-Frequency Vibration Assisted Drilling of CFRP/Ti6Al4V Stack Materials

在叠层材料一体化制孔过程中,CFRP制孔质量极易受到钛合金切屑排出的影响,出现入口撕裂、孔径超差等加工缺陷。为了提高叠层材料的制孔质量,本文分析了振动钻削的运动学特征,确定了理论最小断屑振幅,通过低频振动钻削和传统钻削叠层材料的对比试验重点探讨了不同振幅参数对切削力、切削温度以及制孔质量的影响。结果表明:随着振幅增大,钻削平均轴向力小幅下降,最大轴向力呈现上升趋势;当振幅大于最小断屑振幅时,低频振动钻削在实现有效断屑排屑的同时能够显著降低切削温度,提高孔壁质量和孔径精度;CFRP入口撕裂受振幅的影响最为明显,加工振幅过大会导致入口撕裂的扩大;当振幅为30μm时,入口撕裂区域最小,孔壁粗糙度达到R_a2.16μm,叠层材料总体制孔质量最好,切削温度同时降低了20.8%。

During the single-shot drilling of compound stacks,some defects like entrance spalling and hole diameter out of to lerance are easily induced by the evacuation of titanium alloy chips. In this paper,the theoretical chip breaking limit is deduced through the kinematics analysis of the vibration drilling firstly. Then,to improve the hole quality of stacks,a comparative test between low-frequency vibration assisted drilling and conventional drilling is performed. The effects of different amplitudes on the cutting force,cutting temperature and hole quality are discussed especially. The results show that the average axial force decreases slightly and the maximum axial force tends to rise with the increasing amplitude. If the amplitude is set superior to the limit,low-frequency vibration drilling can reduce the cutting temperature and improve the hole wall quality and hole precision effectively. CFRP entrance spalling is most affected by the amplitude and excessive amplitude will lead to the expansion of the entrance damage. When the amplitude is 30μm,the smallest entrance spalling zone,lower average hole roughness（ Ra2. 16μm） and the best over all quality can be obtained. Meantime,the cutting temperature is reduced by 20. 8%.