High strength aluminum alloys for car-body applications

Aluminum alloys has been used by the automotive industry since many years but recently the demand has increased in response to a growing need for lightweight structural metals. Aluminum alloys are rapidly becoming a material central to vehicle manufacturing. In fact, aluminum is considered the fastest growing automotive manufacturing material. Using aluminum alloys is useful to reduce the automobile weight which produces minor fossil fuel consumption, lower CO2 emission and also an increasing of vehicle performance. This thesis project was born from collaboration between Politecnico di Torino and Centro Ricerche Fiat (CRF) department of Fiat Chrysler Automobiles (Stellantis). The aim of the thesis is focused on the high strength aluminum alloys for car body application used in the production of cars by FCA. After an initial phase of studying the standards and the procedures related to the tests conducted, an experimental analysis has been done to obtain useful results for the manufacture of bodywork components. Tensile test and Stress corrosion cracking test (SCC) has been conducted on two sets of aluminum alloys: 1) Monolithic alloys of the series 7000 and 2) Fusion alloys of series 7000 and 5000 which has different heat treatments. To complete the thesis also an optical emission spectroscopy and a metallography have been done to obtain the chemical composition and the microstructure of the considered alloys.