Effect of Friction Stir Processing (FSP) to the Mechanical Properties of 7075-T73 Aluminum Alloys Plates Welded by Friction Stir Welding

Abstract

Friction stir processing is a new method of changing the properties of a metal through intense, localized plastic deformation ,this process mixes the material without changing the phase (by melting or otherwise) and creates a microstructure with fine, equiaxedgrains , It is used to improve the microstructural properties of metals. In this paper , the enhancement of mechanical properties of friction stir welding specimens at variable rotation speeds (1500,1700 and 1900 rpm ) with constant feed speed(40mm/min) for 7075-T73 aluminum alloy is studied by using the friction stir processing method at the same variable rotation speed and feed speed in order to transform a heterogeneous microstructure to a more homogeneous, refined microstructure.The best results of the weld gained at the parameter 40 mm/min weld speed and 1700RPM rotation speed for the friction stir welding (FSW) and friction stir processing (FSP) where the efficiency reaches to 83.7% for FSW and 92.99% for FSP of the ultimate tensile strength of the parent metal.