The effect of pulverized glass waste particle sizes on the mechanical properties of AA6061-T6 friction stir welded joints.

The study sought to investigate the effect of pulverized glass waste (PGW) particle size as reinforcement for AA6061-T6 joints produced by Friction Stir Welding (FSW). The study utilized three particle sizes of 15 microns, 45 microns and 75 microns of the PGW as reinforcement alongside established process parameters of 900 rpm, 1120 rpm, and 1400 rpm for rotational speed, 25 mm /mi n, 40 mm min-1 and 63 mm/min for traverse speed and 1 degrees, 1.5 degrees and 2.5 degrees for tilt angle in a Taguchi L9 orthogonal array experimental design for the welding process. The welding experiments were repeated for each reinforcement particle size utilized in this work. Parallel-hole reinforcement strategy was used on all joints for the application of the PGW. Microstructural analysis, tensile strength and hardness tests were carried out on the welded joints. The volume percentage of the PGW in the aluminum alloy matrix at the welded joint were determined using Image J Processing software. A processing condition of 900 rpm rotational speed, 25 mm/min traverse speed and 1 degrees tilt angle was found to produce the weldment (sample 4) that has a favourable combination of high tensile strength (77.3 MPa) and high hardness (87.3 BHN). The tensile strength was established to increase as the PGW size decreased. This correlation was found to be statistically significant. The hardness of the welded joint did not show any particular trend with the size of the PGW. However, the hardness of the welded joint increased with the increase in the volume percentage of the pulverized glass waste in the welded joint. A moderate Pearson correlation (0.615) between hardness and PGW volume percentage was found.