Investigating effects of surface treatments in FSW of Al-Li alloys for aeronautic applications
By Egoitz Aldanondo (IK4 LORTEK), Ekaitz Arruti (IK4 LORTEK), Alberto Echeverria (IK4 LORTEK), Pedro Alvarez (IK4 LORTEK), Iñaki Hurtado (Mondragon Unibertsitatea, Faculty of Engineering (MU-ENG))

FSW technology has demonstrated the potential to substitute riveting as the main joining technology for aircraft structure manufacturing. Important benefits such as reductions in manufacturing costs and times can be achieved using FSW to produce lightweight structures made by innovative Al-Li alloys.
In this work, the influence of several surface treatments typically used for aeronautic structure manufacturing such as Thin Film Sulfuric Acid Anodizing (TFSAA) or Sol Gel has been investigated. FSW has been performed to produce stringer-skin type joints using several Al-Li alloy extrusions and sheets such as 2099, 2196, 2060 or 2198. The joints have been produced using as-received materials as well as surface treated materials and the influences on the FSW implementation as well as on the joint properties has been investigated.
This work has been performed in the frame of the project ecoTECH within the AIRFRAME ITD of the Clean Sky 2 programme.