Issue 44

N.M. Khansari et alii, Frattura ed Integrità Strutturale, 44 (2018) 106-122; DOI: 10.3221/IGF-ESIS.44.09 108 M ATERIALS AND METHOD riction Stir Welding (FSW) is a solid-state joining process that utilizes a third body tool to join two facing surfaces. Heat is generated between the tool and material that leads to a very soft region near the FSW tool. It then mechanically intermixes the two pieces of metal at the place of the joint, and then the softened metal due to the elevated temperature can be joined using mechanical pressure which is applied by the tool. Fig. 1 illustrates both the friction stir welding tool and the relevant procedure parameters. Figure 1 : Friction stir welding process, schematically In the present study, cold-rolled 2024 and 5050 aluminum alloy have been selected for friction stir welding process. Chemical composition of aluminum alloy is listed in Tab. 1 [1, 18]. Elements Mg Cu V Ni Cr MN Si Ti Zn Al AA 5050 75.5 0.043 0.010 <0.005 0.010 0.224 0.120 0.018 <0.008 others AA 2024 1.57 4.15 0.001 <0.005 0.014 0.53 0.06 0.09 0.13 ≈93.4 Table 1 : Chemical composition of Aluminum Alloy 2024 [1, 18]. Furthermore, the sheets are cut in dimensions of 3 × 100 × 150 mm and are fixed in preferred fixture. In addition, HSS and H13 have been utilized as welding tool. The chemical composition of FSW’s tools represents in Tab. 2. Elements Fe Si MN Cu C Ni Cr V Co W Hss Tool 75.5 0.32 0.25 0.109 0.88 0.163 3.57 1.90 0.09 7.32 H13 Tool 91.7 1.07 0.47 0.06 0.30 0.04 4.37 0.95 0.45 0.08 Table 2 : Chemical composition of HSS and H13 tools [18]. Figure 2 : HSS tool’s spin used in the present research F