Examination of the effect of B4C and GNP reinforcements on machinability in the machining of Al 6061 matrix B4C/GNP reinforced hybrid composites

In this study, hybrid composite materials with Al 6061 matrix, boron carbide (B4C) and graphene nanoplate (GNP) being reinforced in different ratios were produced with the stir casting method. Afterward, machinability tests were carried out on the hybrid composites produced with the turning method. SNMG 12 04 08 NN LT 10 coded cutting tools were used in turning experiments. Experiments were realized at a fixed cutting depth of 1 mm, in dry machining conditions, using three different cutting speeds and three different feed rates. In the machinability tests, cutting forces and surface roughness values have been measured. At the same time, microscope images of the cutting tool tips were taken. When the data obtained as a result of the experiments were evaluated, it was observed that the cutting forces increased with the increase in the cutting speed, but the surface roughness values decreased to some extent. While the cutting forces increased with the increase in feed rate, there were no significant differences in roughness values and tool wear amounts. It was determined that the most effective parameter on cutting forces, surface roughness values and tool wear were constituted of the changes in B4C reinforcement ratio. It has been observed that the B4C reinforcement phase significantly increases tool wear. Besides, it was evaluated that GNP supplementation had a positive effect on machinability in some machining parameters and showed dry lubricant properties. It was concluded that the porosity and aggregation of the reinforcement element in the composite structure had a negative effect on the machinability properties. In addition, it was evaluated that it would be appropriate to use non-traditional manufacturing methods in addition to conventional machining processes in the processing of highly B4C reinforced composites.