Studying the effect of cutting parameters rotation speed and feed rate on the mechanical properties for friction stir welding area between two aluminum alloys

Abstract

This research concerns with the study the effect of cutting parameters (cutting speed and feed rate) on the mechanical properties of friction stir welding joint of two different aluminum alloys, aluminum alloy (2024-T3) which is used in the manufacture of aircraft, and aluminum silicon magnesium-alloy (6061-T6) that used in the manufacture of cars parts. Where, the sheets were first cut from these alloys with dimensions (240×60×6) mm and then machined to get the dimensions (230×50×5) mm using a CNC milling machine at variable cutting speeds (1000, 1200, 1400) rpm at a constant feed rate (20) mm/min and cutting depth of (0.5) mm to prepare three welding joints. The feed rate was then increased to (50) mm/min at (1000) rpm and the same cutting depth to prepare the fourth weld joint to show the effect of these parameters on the welding process and the mechanical properties of the joint. The friction stir welding was conducted by a vertical milling machine at the rotational speed of (900) rpm and linear travel speed of (30) mm/min to obtain the welding joints between the two aluminum alloys sheets (6061-T6+2024-T3). The results of the tested welded joints showed a decreasing in the mechanical properties (Tensile stress, Yield stress, Strain, Bending stress and Fracture stress) with increasing the cutting speed and decreasing the feed rate. The best result was obtained at the cutting speed (1000) rpm and feed rate (50) mm/min. On the other hand, the surface finish, hardness and microstructure were improved with decreasing the cutting speed and increasing the feed rate due to the increase in plastic deformation.