Friction Stir Welding and Processing of Aluminium Alloys

Abstract

Friction Stir Welding is a method which joint different materials that in traditional weld it can’t be welded. This technique improves properties of materials because to be weld materials don’t pass to the liquid-state, they stay in a plastic state. In this study it has been utilized different aluminium alloys as 6082 and 7042 which have very interesting properties for applications as aerospace or building field. Concerning Al-6082, light microscope shows grain refinement in stirred zone and the movements of material due to this technique. TEM shows the difference in dislocations and precipitates density in different parts of the sample. On aluminium 7042-T6, light microscope shows also the different grain sizes in the different zones of the material. SEM micrographs present the chemical composition and different images of samples. In case of micro-hardness test, the profile illustrate a typical hardness of precipitation metals with W profile, where on TMAZ and Stir zone hardness is lower than in the base material.