Design, Modelling, Fabrication, and Testing of Vertical Milling Machine Fixture for Friction Stir Welding Operation

In this work, a simple and robust fixture was designed, modeled, and fabricated for facilitating the friction stir welding process on a vertical milling machine with easy loading/unloading of workpieces. Four different structural materials, i.e., Mild Steel (MS), Grey Cast Iron (GCI), Die Steel (DS), and Hard alloy (HA), were considered for the fixture material. CAD software designed model of the fixture was imported to finite element solver for stress-deformation analysis. From the results of dynamics analysis, Mild Steel showed better performance, i.e., maximum deformation 0.14719 mm and comparable equivalent stress 42.724 MPa as compared to GCI (0.28196 mm, 42.821 MPa), DS (0.15508 mm, 42.821 MPa), and HA (0.17231 mm, 42.821 MPa). Furthermore, MS is commercially available easily than the other three. Therefore, the Mild Steel block was used to fabricate the Friction Stir Welding fixture, and the testing of the fabricated fixture was then carried out by running the FSW experiments. Hardness measurements of the tested specimen proved the practical applicability of fabricated fixture. It was observed that developed fixture reduced set-up time significantly and facilitated a wide range of tool profile machining.