Tool wear processes in low frequency vibration assisted drilling of CFRP/Ti6Al4V stacks with forced air-cooling
Tool wear processes in low frequency vibration assisted drilling of CFRP/Ti6Al4V stacks with forced air-cooling
复制标题
强制风冷 CFRP/Ti6Al4V 叠层低频振动辅助钻孔中的刀具磨损过程
DOI：
10.1016/j.wear.2019.01.005
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发表时间：
2019-04-30
期刊：
影响因子：
5
通讯作者：
Ren, Fei
中科院分区：
文献类型：
--
作者：
Li, Chao;Xu, Jinyang;Ren, Fei
由于铆接和紧固装配的需求，在现代航空航天制造领域，一次性钻削碳纤维增强复合材料（CFRP）/钛合金（Ti6Al4V）叠层对于保证生产效率至关重要。在本研究中，设计了一种低频振动辅助钻削（LFVAD）与强制风冷相结合的新型集成系统，以研究CFRP/Ti6Al4V叠层钻削中的刀具磨损问题。所使用的无涂层整体硬质合金刀具采用特殊设计的螺纹柄，以适配LFVAD刀柄的适配器。螺纹柄钻头的主要几何特征包括直径6.35毫米、顶角140度、螺旋角30度以及两个切削刃。在不同条件下对LFVAD的钻削温度和钻削力进行了原位测量，并将结果与相同钻削条件下的常规钻削进行了比较。研究发现，借助强制风冷，振动钻削的间断切削所产生的小钛屑段能够被有效去除。与常规钻削相比，在强制风冷的LFVAD条件下，后刀面磨损速率更慢，切削温度更低。两种钻削方法的主要磨损形式均为粘着磨损；然而，在LFVAD中，化学磨损更加明显，同时切削刃崩刃占主导地位。总之，从减少刀具磨损的角度来看，强制风冷的LFVAD被证实能够提高CFRP/Ti6Al4V叠层的可加工性。
Drilling CFRP/Ti6Al4V stacks in one-shot time becomes essential in the modern aerospace manufacturing sectors in order to guarantee the productivity due to the demands of riveting and fastening assembly. In the present study, a novel integrated system of low frequency vibration assisted drilling (LFVAD) coupled with the forced air-cooling was designed to investigate the tool wear issues in drilling of CFRP/Ti6Al4V stacks. The used un-coated solid tungsten carbide tools were specially designed with threaded shanks for fitting the adapter of the LFVAD tool holder. Main geometrical features of the threaded shank drills include a 6.35 mm diameter, a 140 degrees point angle, a 30 degrees helix angle and two cutting edges. Drilling temperatures and forces were in-situ measured for the LFVAD subjected to varying conditions, and the results were compared with the conventional drilling under the identical drilling conditions. It is found that the small titanium chip segments produced by the interrupted cut of vibration drilling can be removed efficiently via the help of the forced air-cooling. Compared with the conventional drilling, slower flank wear rates and lower cutting temperatures are identified under the LFVAD with the forced air-cooling. The adhesive wear is the main wear mode for both drilling methods; however, the chemical wear becomes more pronounced while the cutting edge chipping predominates in the LFVAD. In sum, the LFVAD with the forced air-cooling is confirmed capable of improving the machinability of the CFRP/Ti6Al4V stacks from the aspects of reducing tool wear.