Drilling of titanium aluminide at different aspect ratio under dry and wet conditions

Abstract

To increase the wide use of intermetallic titanium aluminides for various fields of engineering application, a broad understanding of the machinability of these material is essential. The present work is focussed on the drilling of this intermetallic alloy at low and high aspect ratio under dry and wet environments. The machinability in dry and wet conditions were assessed based on the thrust force, torque, burr formation, surface quality, tool condition and chip morphology. The supply of cutting fluid is found to be effective in reducing the thrust force and torque and producing quality surface. Burr, being an important factor in drilling have also been studied, and the findings show the presence of uniform burr with and without roll back in dry and wet condition respectively. Surface defects formed and their intensity during both the machining environments were analysed. Built up edge formation on the drill tool was detected in all cutting conditions. The transformation of chip shape as the depth of hole progresses is also detailed in the present work. Furthermore, the study demonstrates the feasibility of drilling titanium aluminide in dry and wet environment. The overall results indicate that dry environment is not viable for high aspect ratio drilling.