| Because of their excellent mechanical properties,CFRP and Titanium have been widely used in the field of aerospace.In aircraft assembly process,CFRP structural parts usually connect locally with titanium alloy components using bolts,constituting CFRP/Ti stacks.Because CFRP and titanium alloy all belong to the typical difficult-to-machine materials and their processing performance difference is huge,in addition CFRP hole wall surface will be scratched when the Ti continuous chip discharge,and resulting in low hole accuracy and poor surface quality.Axial vibration drilling as a kind of compound machining method,can make traditional drilling continuous cutting into discontinuous cutting,thus to achieve the effect of chip breaker.In view of this,this article does drilling test of CFRP/Ti stacks with the processing method of axial vibration drilling,mainly do research in three aspects of Ti chips,cutting force and hole quality,the main research content is as follows:(1)Mechanism of chip breaker of vibration drilling is analyzed and the chip end conditions are given,and the theory of chip size calculation formula is derived.Ti chip morphology of traditional drilling are compared with vibration drilling,verifying the chip break effect of vibration drilling,and studied the influence of amplitude,rotational speed and feed rate on the chip size.(2)Compare the drilling force difference between traditional drilling and vibration drilling of CFRP/Ti stacks,and analysis the reasons of the differences in theory;studied the influence of amplitude,speed,and feed rate on drilling force.(3)The traditional drilling and vibration drilling are compared from CFRP morphology of hole wall,the entrance tearing of the CFRP,CFRP hole surface roughness,Ti exit burr and pore size precision aspects,and analyzes the principal causes of the difference;studied the influence of amplitude,speed and feed rate on the hole quality,and then analysis the main reasons of hole defects. |
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