Improving Joint Features and Mechanical Properties of Pinless Fiction Stir Welding of Alcald 2A12-T4 Aluminum Alloy

摘要: As a new solid state welding, pinless friction stir welding (PFSW) can be used to join thin-wall structures. In this study, four tools with different groove distributions were designed and manufactured in order enrich technological storage of PFSW obtain sound joint high quality alclad 2A12-T4 alloy. The results show that the small-obliquity tool is detrimental transfer plasticized materials, resulting formation kissing bond defect. For through-groove or large-curvature tool, bigger flashes form on surface layer observed nugget zone (NZ), deteriorating mechanical properties. Compared above-mentioned three tools, using six-groove rational curvature obliquity not only yield small thickness reduction, but also prevent from flowing into NZ, which has potential weld thin aluminum alloys. Meanwhile, tensile strength elongation reach maximum values 362 MPa 8.3%, up 85.1% 64% BM.