Spot welding of aluminum alloys for automotive applications

Aluminum is always more frequently employed in automotive industries instead of the heavier iron-based alloys in order to gain advantages in terms of weight and increasing consequently the performance. This study aims to analyze, in partnership with Centro Ricerche Fiat S.C.p.A., the micrographic and mechanical characteristics of a set of two spots welded experimental alloys, never launched on the market, to understand if they can be ideal for future automotive applications. The thesis work is divided into a first bibliography part in which is illustrated the state of the art of aluminum components in car manufacturers, and a second research part describing all the tests executed on the welded specimens. The research work consists in welding the two experimental alloys in the laboratory with a spot welding machine, prepare the specimens for a microscopic analysis in which the weld nugget is analyzed, and then perform the hardness Vickers test, traction, and fatigue tests on a new set of specimens. With the experimental section accomplished, some conclusions will be drawn on the future possible utility of these new aluminum alloys.