The effect of SiC/Al2O3 particles used during FSP on mecinnical properties of AZ91 magnesium alloy

Friction stir processing, as a method of changing the properties of a metal, through intense, localized plastic deformation, has been developed based on the basic principles of friction stir welding. In the current research, mechanical properties of AZ91 magnesium alloy were modified by the application of friction stir processing. Surface composites using SiC as well as Al2O3 nano-particles were developed. Yield and tensile strengths as well as hardness values of specimens were measured. The results showed that friction stir processing modified the size of grains noticeably and improved the mechanical properties. The results also indicated that SiC particles were more beneficial than Al2O3 particles with regard to improvement of the properties. It was also concluded that homogeneous distribution of particles resulted in the decrease of grain sizes to 3 mu m and the increase in strength and formability index to 390 MPa and 6500 MPa, respectively.