The effect of cutting parameters on surface roughness and tool wear in the milling of 6061 aluminum alloy performed with the cryogenic process

Aluminium and its alloys are the most commonly used materials after iron and steel in industry today. The alloy referred to as the 6061 aluminum is widely used in the defense industry, as well as in heavy industries such as aircraft manufacture, shipbuilding, construction of military bridges, and space applications. In this study, an aluminum alloy of 6061-T651 with dimensions of 80 x 80 x 30 mm underwent a surface milling process. Furthermore, the cryogenic process was applied to the material and the cutting tools. A total of 108 tests were performed with 27 tests for each of the matchings for normal material with normal tools, normal material with cryogenic tools, cryogenic material with normal tools, and cryogenic material with cryogenic tools. Full factorial design was used for the test design, with cutting parameters defined as cutting tools with 3 different coatings (Al2O3-TiCN-TiN, TiAlN-NANO, and AlTiN multilayer), at 3 different cutting speeds (250, 350, 450 m/min), and with 3 different feed rates (0.15, 0.30, and 0.45 mm/tooth). Shaving dimensions were kept constant at 0.5 mm. Following each test, surface roughness of the treated surface was measured at the beginning and end sections. Furthermore, tool wear in cutting tools was examined under the optical microscope and the temperature in the cutting zones was observed with a thermal camera. Test results were evaluated with a variance analysis, as well as using 2D and 3D graphics. Best test results were obtained with the cutting tools that were treated with the cryogenic process. A review of the temperatures measured with a thermal camera showed that the lowest temperatures were obtained from experiments conducted with the materials and tools that previously underwent cryogenic treatment.