Lightweight and durable materials such as aluminum alloys are widely used in sectors such as defense industry, aerospace industry, automotive industry, and high-speed train manufacturing. Some of these materials cannot be welded by conventional methods due to their high thermal conductivity and low melting point. In welding processes, the material properties are expected to be as close as possible to base material. Friction stir welding (FSW) is a joining method that provides welding below the melting point of materials that cannot be welded by conventional methods or where the welding process causes the mechanical structure of the material to deteriorate. In this study, FSW application, advantages and disadvantages and usage areas of friction stir welding were examined.

Friction stir welding frequently produces a superior microstructure and mechanical properties than conventional methods for welding nonferrous materials and alloys. In this study, friction stir welding was used to join sheets of the aluminum alloy AA7075 with commercially pure copper cpCu. Two rotational speeds, 660 and 920 rpm, and three welding speeds, 18, 32 and 54 mm × min−1, were studied to determine the effects of these parameters on the structure and mechanical properties of friction stir welded AA7075-cpCu. The joint performance was investigated by conducting optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), by microhardness measurements and mechanical testing (e. g. tensile tests). A maximum tensile strength of 224 MPa and percentage elongation of 2.49 were obtained when friction stir welding process parameters, namely rotational speed and welding speed, were kept at 660 rpm and 32 mm × min−1, respectively.

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Practical problems like measurement, control and linearization of mechanical outputs can be solved within the context of function generation problem. In this work, an exemplary application associated with the measurement of water velocities in open channels has been shown, and the resulting apparatus has been constructed and tested under laboratory conditions. To test its performance, velocities, have been compared with those obtained by the constructed prototype. The results have been observed to be consistent with each other.