Anagrafe della ricerca

The aim of the research project is the development and properties assessment of an innovative high-strength lightweight alloy for light electric vehicles manufacturing. According to the European Union, the transport sector produces the 28% of the total carbon dioxide (CO2) and the use of Electric Vehicles (EVs) or assisted vehicles should be viable solutions to reduce emmissions. Hybrid mobility should also increase the health quality of citizens by promoting active mobility, thus decreasing sedentariness diseases. In this view, the development of agile modular vehicles could catalyse the mobility transition to more distributed and clean solutions, simpler and more compact, affordable with reduced maintenance costs and readily available. The lightweighting trends in mobility driven by sustainability, cost savings, and performance increased the demand for materials and design concepts able to overcome the basic weight reduction and structural efficiency limits. Particular attention is paid to light metals, recyclable and flexible in terms of performances which can be further enhanced by innovative design solutions enabled by additive manufacturing (AM) technologies, mainly laser powder bed fusion (LPBF). Extremely fine microstructures characterized by outstanding mechanical properties as well as improved components stiffness due to the almost infinitive design solutions. In addition, the powder feedstock used for the manufacturing can be tailor-made inside gas atomizers, which enable the development of brand-new alloys designed to overcome traditional alloys compositions, performances as well as durability. Among them, alloys based on Al-Si-Mg system with addition of elements like Cu or Ni, or with addition of ceramic micrometric reinforcements, such as TiC or TiB2, are very promising and some preliminary studies seem to offer outstanding outlooks that can fit well with the requirements of electric mobility transition. In the last years, several studies pointed out that LPBF alloys has unique properties which led to different behaviours compared to the same alloys processed through conventional processes in terms of corrosion, fatigue and corrosion-fatigue resistance. Corrosion performances must be investigated as they affect the material durability, which is strictly connected to sustainability and safety. Since several years the collaboration between Politecnico di Torino - leader in the development of new alloys by AM - and the Università degli Studi di Bergamo - recognized at international level for the specific expertise in the study of corrosion behaviour of alloys produced by means of LPBF - is well established. In the present project, the two teams will be involved in the design and production by gas atomization of a new alloy to be manufactured by LPBF for modular EVs and then in the microstructural and mechanical characterization as well as in the corrosion, stress corrosion cracking and corrosion-fatigue characterizations.