振动辅助钻削对CFRP/钛合金叠层结构孔径阶差影响规律实验研究

Experimental Study on the Influence of Vibration-assisted Drilling on CFRP/Titanium Alloy Laminated Structures

在飞机部件装配过程中,CFRP/钛合金叠层结构的连接十分常见,而由于两种材料迥然不同的材料性能,导致制孔后存在孔径阶差,严重影响了CFRP/钛合金结构的疲劳强度。本文开展了低频轴向振动辅助钻削的正交实验,分析了低频振动辅助钻削工艺参数与切削力和切屑形态的关系以及工艺参数对CFRP/钛合金孔径阶差的影响。结果表明,由于低频振动辅助钻削刀具的周期性进给,钛合金切屑由连续长切屑变为扇形短屑,减少了对CFRP的扩孔效应,钻削区域切削热降低,平均轴向力降低;另外,振幅和进给量对孔径阶差的影响较为显著,而主轴转速的影响较小,且孔径阶差随着振幅的增大先减小后增大,随着进给量的增大而增大。通过试验验证和分析,确定面向孔径控制的最优工艺参数组合方案:主轴转速为600 r/min、进给量为0.02 mm/r、振幅为150μm。

In the assembly process of aircraft parts,the connection of CFRP/titanium alloy laminated structure is very common.Due to the very different material properties of the two materials,the pore size order difference exists after hole making,which seriously affects the fatigue strength of CFRP/titanium alloy structure.In this paper,the orthogonal experiment of low-frequency vibration-assisted drilling was carried out,and the relationship between the technological parameters of low-frequency vibration-assisted drilling and the cutting force and chip morphology was analyzed,as well as the influence of technological parameters on the pore size difference of CFRP/titanium alloy.The results show that titanium alloy chips change from long continuous chips to short sector chips due to the periodic feed of low frequency vibration-assisted drilling tool,cutting heat in drilling area decreases and average axial force decreases.In addition,the influence of amplitude and feed on the aperture order difference is relatively significant,while the influence of spindle speed is relatively small.Moreover,the aperture order difference first decreases and then increases with the increase of amplitude,and then increases with the increase of feed.Through test verification and analysis,the optimal process parameter combination scheme for aperture control-oriented is determined:spindle speed is 600 r/min,feed is 0.02mm/r,and amplitude is 150μm.