Friction Stir Repair of Cast Magnesium Alloy Defects and Mechanical Properties Analysis
The internal defects of AZ91D cast magnesium alloy were repaired by friction stir processing(FSP).Optical microscope(OM),scanning electron microscope(SEM)and tensile test were used to analyze the microstructure and mechanical properties of cast magnesium alloy before and after repair.The results show that the porosities in the cast magnesium alloy can be fully eliminated by the optimized FSP parameters.The microstructure and mechanical properties of repaired regions are obviously different from those before repair.The microstructure of repaired zones is composed of isoaxial grains ranging from 5 to 15 μm.The microhardness of the stirred zone is 10%-15%higher than that of the as-cast metal.The tensile strength of the FSP sample is 80%higher that of the base material,and the elongation is about 1.8 times higher than that of the base material.
friction stir processingmicrostructure and propertymagnesium alloyporosity