Process and Composition Parameter Optimization of Friction Stir Process of AA 6101 Aluminum Composites using Response Surface Methodology

Friction stir processing (FSP) is an innovative solid-state technique in which the material remains unmelted and unrecast, with process parameters such as tool rotational speed, tool feed, and axial force significantly influencing the mechanical properties. Recent studies have included metal oxides or carbides in the FSP process, yielding surface composites of aluminum alloys. In addition to the process parameters, it is posited that the composition of additives may influence the mechanical properties. Traditionally, statistical analyses focused on modeling process parameters to enhance the response behavior of composites. In this investigation, however, both process parameters (tool rotational speed and tool feed) and composition parameters (SiC wt% and Graphene wt%) were incorporated to achieve optimal mechanical properties of the composites. The research involves the synthesis of AA6101 aluminum composites by the modulation of tool rotational speed and feed, while concurrently adjusting the concentration of reinforcement additives (SiC wt% and Graphene wt%). The ultimate tensile strength, flexural strength, and hardness of the produced composites were evaluated using a universal testing machine and a Vickers hardness tester. The central composite design technique and mathematical model were developed using response surface methodology, incorporating two parameters, three levels, and 15 runs, to establish the relationship between the FSP parameters (process and composition) and the responses (tensile strength, flexural strength, and hardness). The findings indicate that the optimal responses of the FSP process, as assessed by the response optimizer, are 330 MPa (UTS), 130 MPa (FS), and 110 HV (Hardness).

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