Machinability of 7116 Structural Aluminum Alloy

The aim of the present work is to study the effect of heat treatment conditions on the surface roughness of 7116 structural aluminum alloy. The specimens were prepared by casting to attain the required chemical composition, and then hot extruded to form bars. The extruded bars were then subjected to the different proposed heat treatment cycles, namely, annealed, naturally aged, artificially aged, and artificially aged with superimposed free forging and the as-received condition. The specimens were then turned at different cutting conditions—velocities, feeds, and depth of cuts—using high speed tools (HSS). The surface roughness values were then assessed. Based on the results obtained, the artificially aged condition with superimposed effect of cold forging shows the best machinability (presented by the measured surface roughness) as a result of the increase in hardness. Hardness has a pronounced effect on the formation of built-up edge (BUE) for the material under investigation.