Paper Title
Laboratory Research on Effect of Friction Stir Processing | (FSP) On Aa-7020 Aluminum Alloy

Friction stir processing as a promising thermo mechanical approach aims on altering the microstructural and mechanical properties of material in order to obtain the highest performance in terms of properties, cost and lead time. This study addresses FSP of 7020 aluminum alloy. The effect of variation in the ratio of rotational and translational speeds (i.e., ω/f) is examined on mechanical properties and the microstructure of AA-7020 aluminum alloy. The value of ω/f is varied from 22 rev/mm to 125 rev/mm. The results show that with increasing ω/f, the grain size decreases. When ω/f ranges from 22 to 28, average hardness, ultimate strength and yield strength increase from 75 HV to 103 HV, from 313- 364 MPa and from 173 MPa to 208 MPa, respectively. However, for ω/f ranging from 28 to 125, a reduction has been noticed in these properties. Regarding microstructure, it is found that the size of grain in the processed zone is small and the direction of grain is random. Besides mechanical properties, observations regarding the effect of ω/f on surface quality are also made to show that larger values of ω/f lead to poor surface texture. Keywords- Stir Processing, Hardness, Impact, Quality, Microstructure, Tensile, AL7020