Tool wear mechanism in low-frequency vibration–assisted drilling of CFRP/Ti stacks and its individual layer

The effect of MQL on tool wear progression in low-frequency vibration-assisted drilling of CFRP/Ti6Al4V stack material

“…This observation supports the negative effect of the high axial tool velocity which resulted in a severe toolworkpiece impact mechanism, as described in section 3. Contrary to [26], the chisel edge suffers a severe fracture rather than Ti adhesion due to the negative clearance angle. This difference could be attributed to the utilization of higher A m range (0.1 to 0.25 mm) compared to only 0.06 mm.…”

“…This effect was attributed to the relatively higher cutting temperature for the CD. The high chemical a nity toward most of the industrially used drill bits material highlights adhesion as a dominant wear mechanism during the drilling process of Ti materials [4,11,26,36,37]. This process resulted in a built-up edge (BUE) formation, that leads to tool fracture or chipping and consequently, poor hole quality and short tool life will be observed.…”

“…Despite the promising results of LF-VAD in terms of tool durability, the presented investigations failed to discuss two main factors; the machining productivity and the associated effect of tool wear progression on the hole quality. The investigated range of cutting speed was limited by 20 m/min [26,27], without any clari cation of the associated hole quality that represents the critical criteria for the aerospace industry. In a previous study [25], the effect of LF-VAD on tool wear and the associated hole quality was presented using cutting speeds up to 56.52 m/min which is three-folds the illustrated range, using a recommended vibration amplitude [11].…”

“…This achievement resulted in a better chips evacuation e ciency with a preferable cyclic cutting/cooling duty [23]. Thus, lower cutting temperature, better geometric accuracy, high surface quality, and compressive residual stresses can be induced [19,20,23,25,26].…”

New developments in vibration assisted machining of aerospace materials

“…15. Porównanie zużycia wierteł stosowanych do wiercenia stosu CFRP/Ti [24] UVAM&MQL, ułatwiło dostęp chłodziwa do krawędzi skrawającej, co jeszcze bardziej poprawiło efektywność obróbki stopów lotniczych. Zastosowanie drgań o niskiej częstotliwości do wiercenia superstopów znacznie poprawia łamanie i ewakuację wiórów, a w przypadku stosów poprawia jakość wykonywanych otworów, zmniejsza delaminację i zwiększa trwałość ostrza.…”