Influence of Peripheral Milling on Machining of Aircraft Grade Aluminum Alloy

Peripheral milling is a metal cutting operation in which the cutter produces a machined surface parallel to the\ud axis of rotation of cutting. This is approached either by upmilling or downmilling methods. The fundamental difference\ud among these modes of milling shows a marked variation in the magnitude of cutting forces during the process, chip\ud formation and the quality of metal cutting. This work examines the difference brought out on the resultant\ud component/part in terms of surface finish and hardness on aircraft grade precipitation hardenable Aluminum 2124 T851\ud alloy. Other cutting parameters like feeedrate, depth of cut, spindle speed, tool over hang length, tool diameter, number of flutes etc., are maintained identical on both types of milling. This study is examined on finishing operation of Aluminum plates of different aspect ratio in attaining a defined thickness on all the specimens. Metal cutting is carried using three different types of cutters for both upmilling and down milling strategies. The surface texture, surface finish and hardness are evaluated and the results are presented. The results indicate that hardness values are relatively high in down milling strategy for the same machining variables as against the case of upmilling and the surface roughness is higher in case of down milling compared to upmilling operations