Microstructural engineering of structural aluminium alloys

• Grant number: 14/03870-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2014
• End date: April 30, 2015
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Haroldo Cavalcanti Pinto
• Grantee: Larissa Fernandes Batista
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Engineering components are designed exploiting the properties of materials, which, in most of the cases, are formed by more than one phase. The property profiles of multiphase materials are determined by the combination of the properties of the individual phases and the three-dimensional (3D) architecture formed by them, which is given by their proportion, size, morphology and spatial arrangement.Aluminium alloys are used for structural elements in transportation (automotive, aerospace) and sporting goods. Their advantages are their low weight, high specific stiffness and relatively high specific strength, particularly under bending loads, assets that go along with the industrial efforts of weight reduction of products. The capability of multiphase alloys to withstand external thermo-mechanical loads is determined by the mechanical and physical properties of the microstructural components, their thermal/mechanical stability and their geometrical arrangement (including size, proportion, morphology, distribution, interconnectivity, contiguity). All these parameters may vary during production and service and, therefore, physical aspects such as nucleation and growth of phases, diffusion controlled morphological changes or bonding of interfaces must be considered to understand the thermo-mechanical behaviour of the alloys. Furthermore, microstructural features influence the stress partition between phases, stress localization as well as possible damage nucleation and evolution. The sensitivity of the mechanical properties to microstructural changes in structural aluminium alloys has been extensively studied and reported but new insights can be gained nowadays due to the advance of modern characterisation methods that allow to observe the evolution of the microstructure in situ and/or three-dimensionally. The proposed project concentrates on the investigation of the formation and evolution of three-dimensional multiphase arrangements of selected structural aluminium alloys during thermal and/or thermo-mechanical treatments aiming at controlling their microstructure and, consequently, their thermo-mechanical behaviour. This will require the use of state of the art in situ 3D imaging methods to reveal the internal architecture of the alloys together with in situ bulk diffraction methods to follow the formation and evolution of microstructural phases as well as their evolution and load carrying capability during different loading conditions.