Microstructural characterisation of material adhered over cutting tool in the dry machining of aerospace aluminium alloys

In this work, scanning electron microscopy has been used in order to identify the effects of adhesion on the dry turning processes of different aerospace aluminium alloys. Analysis with energy dispersive spectroscopy allows distinguishing different composition characteristics between built-up layer (BUL) and built-up edge (BUE) formation in the processes we studied. A preliminary hypothesis on the formation of BUL and BUE, taking into consideration the temperature in the region of initial deformation has been formulated. According to this hypothesis, BUL formation is preceded by a process of incipient fusion, which releases intermetallic particles. Once BUL has formed initial cutting conditions change enabling BUE formation by mechanical adhesion. Additionally, the evolution of BUL and BUE with the time of machining has been also studied.