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188 Effect of Friction Stir Processing Parameters on the Mechanical and Dynamic Responses of AA 5052-H32 Mohammed Gamila,*, W.M. Faroukb and Mamdouh I. Elamyc,d aDepartment of Mechanical Engineering, Faculty of Engineering at Shoubra, Benha University, Cairo, Egypt. bMechanical Engineering Department, Faculty of Engineering, Benha University, Benha, Egypt. cIndustrial Engineering Department, Faculty of Engineering, Northern Border University, Arar, Saudi Arabia. dProduction Engineering & Mechanical Design Department, Faculty of Engineering, Menoufia University, Menoufia, Egypt. *Corresponding author: mohammed.gamil@feng.bu.edu.eg Abstract: The present study investigates the friction stir processing (FSP) effect on the mechanical and dynamic response of AA5052-H32.FSP was applied on a 1.5 mm thick aluminium sheet at three rotational speeds (495 rpm, 850 rpm, 1660 rpm) and two longitudinal feed rates (24 mm/min, 42 mm/min). The processed samples were mechanically tested by tensile and micro-hardness tests. The macrostructure of the FSPed zone was also investigated. The highest detected ultimate tensile strength (207.5 MPa) was observed at 850 rpm and 42 mm/min. The FSPed conditions 1660 rpm and 24 mm/min provide the highest mean value of micro-hardness (66.57 HV) at lowest standard deviation (SD). The macrostructure showed the successful stirring process. The dynamic behavior was investigated at the processed conditions by applying free vibration analysis at different sets of boundary conditions. By introducing unified mechanical parameters, the mathematical finite element analysis (FEA) is efficient in computing the Eigen-nature of FSP. The experimental analysis was carried out using frequency response function (FRF) using hammering method. The comparison between experimental and numerical models showed the efficiency of the proposed mathematical model for the FSP. The change of rotational speed from 495 rpm to 850 rpm increases the fundamental natural frequency by 7.11%, while the change from 850 rpm to 1660 rpm decreases it by 13.1%. The change of boundary fixation from C-C to C-F decreases the fundamental natural frequency by an average of 40.22%.The highest damping factor was occurred at 1600 rpm, 42 mm/min, and C-F boundary fixation. Keywords: Friction stir process; Aluminium alloys; Dynamic analysis; Finite element modeling; Frequency response function (FRF). 1. Introduction Aluminium alloys offer good corrosion resistance, good ductility, high thermal conductivity, high toughness combined with good formability and good weld ability. In addition, Aluminium alloys have superior strength to weight ratio and high fracture toughness. Therefore, they are widely used as structural lightweight materials for many automobiles, aeronautics, railway vehicles, medical, chemical, and other industrial applications [1, 2]. FSP is a solid-state operation used to enhance the mechanical properties and to apply surface modifications. In addition, it is used for refining the microstructure. The tool rotation speed and longitudinal feed rate are the main parameters that ENGINEERING RESEARCH JOURNAL (ERJ |
