Development of an alternative route by solid state processing for recycling the containing lithium aluminum alloy AA2050

• Grant number: 14/14854-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: October 01, 2014
• End date: March 31, 2016
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Transformation Metallurgy
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Kátia Regina Cardoso
• Grantee: Vanessa Guido
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Federal de São Paulo (UNIFESP). Campus São José dos Campos. São José dos Campos , SP, Brazil

Abstract

Aluminum alloys containing lithium from the called 3rd generation have great potential for applications in the aerospace industry due to features such as lower density, higher elastic modulus and fatigue resistance superior to the conventional alloys of 2XXX and 7XXX series. This 3rd generation of Al-Li alloys still has corrosion resistance and fracture toughness superior to the 1st and 2nd generations alloys. However, the application of these alloys in new projects demand the search for solutions to some negative aspects associated with its use as the high cost and the need for a dedicated system of waste and chips management for recycling. The conventional recycling processes involving melting scrap have restrictions on processing of Li containing alloys due to their high reactivity with the atmosphere and with refractory materials of furnaces, besides their low vapor pressure leads to volatilization during melting and loss of lithium content. Moreover, the high toxicity of lithium vapor causes negative impacts on environmental and people health involved in the process. This project aims to develop an alternative route for recycling chips of aeronautical grade aluminum-lithium alloys. This route is based on powder metallurgy in which the main steps, grinding and consolidating by hot extrusion, occur totally in the solid state. Chips of AA2050 aluminum alloy ceded by Embraer, containing about 1 wt% Li, will be employed for the development of this route. This alternative route has three important appeals, it avoids losses of up to 40% of alloying elements by oxidation, prevents loss of light and low vapor pressure elements, mainly in Li containing alloys which vapor brings negative environmental and health impacts, and enables obtaining a material with properties similar to the original one, and consequently of high added value. As a result of this project is expected to obtain a design of sustainable and economically viable process for the production of aeronautical grade aluminum alloys from machining byproducts of aluminum parts in the aerospace industry. It is also hoped that this initiative, along with the knowledge generated in terms of metallurgy of these alloys, may contribute to the beginning of participation of national companies in the supply of such alloys to market, spreading their use in other transportation segments such as automobile and rail, and to energy sector at a more attractive price. (AU)