Study of fatigue crack nucleation in aluminum alloys dissimilar friction stir welded (FSW) subjected to corrosive environments

• Grant number: 14/18766-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2014
• End date: April 30, 2015
• Field of knowledge: Engineering - Aerospace Engineering
• Principal Investigator: Cassius Olivio Figueiredo Terra Ruchert
• Grantee: José Eduardo Passarin
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

The aerospace industry has sought improvements in the concept of structural integrity to ensure safer and lower manufacturing costs, aircraft maintenance and operation. The search for new materials and processes that ensure lighter aircraft direct result in lower fuel consumption and therefore more operationally viable, have been given virtually all components of an aircraft. These items, materials / processes, there are the aluminum alloys (2xxx and 7xxx) and friction welding mixture (FSW) for its cost / benefit ratio. This study has the main objective to evaluate the fatigue properties and fatigue-corrosion in dissimilar Al alloys (2024 and 7475) of high-strength friction welded (FSW). A range of assays will be performed in order to characterize a thorough and detailed way the thermo-mechanically affected area (nugget) and the heat affected regions of both materials. Among the highlights are the trials of fatigue (SN) that will run in midair and in 3.5% saline mist. This will be analyzed in parallel and perpendicular to the weld line direction. These data will allow the structural optimization as well as a reliable assessment of the feasibility of using this technology, and predict the behavior of such a joint during the operation of an aircraft. Furthermore, this project has the challenge to provide the information that constitute the base of the pyramid in the concept of technological development for 'building block'.