Influence of Tool Geometry and Process Parameters on the Properties of Friction Stir Spot Welded Multiple (AA 5754 H111) Aluminium Sheets

Materials

Milan Pecanac¹  Danka Labus Zlatanovic¹  Sebastian Balos¹  Stefan Rasche²  JeanPierre Bergmann²  Saurav Goel³ 

[1] Department of Production Engineering, Faculty of Technical Science, University of Novi Sad, 21000 Novi Sad, Serbia;Department of Production Technology, Technische Universität Ilmenau, 98693 Ilmenau, Germany;School of Engineering, London South Bank University, London SE1 0AA, UK;

关键词: friction stir spot welding;    multiple ultrathin sheets;    tool geometry;    5754-H111 aluminium alloy;    small punch test;    scanning acoustic microscopy;   

DOI  :  10.3390/ma14051157

来源: DOAJ

【 摘 要 】

Friction stir spot welding is an emerging spot-welding technology that offers opportunities for joining a wide range of materials with minimum energy consumption. To increase productivity, the present work addresses production challenges and aims to find solutions for the lap-welding of multiple ultrathin sheets with maximum productivity. Two convex tools with different edge radii were used to weld four ultrathin sheets of AA5754-H111 alloy each with 0.3 mm thickness. To understand the influence of tool geometries and process parameters, coefficient of friction (CoF), microstructure and mechanical properties obtained with the Vickers microhardness test and the small punch test were analysed. A scanning acoustic microscope was used to assess weld quality. It was found that the increase of tool radius from 15 to 22.5 mm reduced the dwell time by a factor of three. Samples welded with a specific tool were seen to have no delamination and improved mechanical properties due to longer stirring time. The rotational speed was found to be the most influential parameter in governing the weld shape, CoF, microstructure, microhardness and weld efficiency. Low rotational speeds caused a 14.4% and 12.8% improvement in joint efficiency compared to high rotational speeds for both tools used in this investigation.

【 授权许可】

Unknown