Ripandeep Singh – författare

Friction stir processing (FSP) is a solid state process in which a non consumable stirring (rotating) tool is plunged into a work piece up to half thickness, which causes intense plastic deformation, material mixing, and thermal exposure, resulting in refinement of micro structural properties, enhancement of mechanical properties, and homogeneity of the processed (nugget) zone. The FSP technique has been successfully used for producing fine-grained structure and surface composite, modifying the microstructure of materials, synthesizing composites like metal-metal composites. The use of FSP generates significant frictional heating and intense plastic deformation, thereby resulting in the occurrence of dynamic recrystallization in the stirred zone (SZ). Although there is still a controversy about the grain-refinement mechanism in the SZ, it is generally believed that the grain refinement is due to dynamic recrystallization. Therefore, the factors influencing the nucleation and growth of the dynamic recrystallization will determine the resultant grain microstructure in the SZ. It has been demonstrated that the FSP parameters, tool geometry, material chemistry, workpiece temperature, vertical pressure, and active cooling exert a significant effect on the size of the recrystallized grains in the SZ.

The need for low weight and high performance structural materials has revolutionized the technology and has led to the emergence of new processes and methodologies. Friction stir processing (FSP), based on the principle of friction stir welding, is an emerging solid state metal working process. This technique causes intense plastic deformation and high strain rates in the processed material, resulting in precise control of the microstructure through material mixing and densification. FSP process has been successfully used for achieving significant grain refinement and enhancement of surface properties. The present work focuses on the study of behavior of Aluminium cast alloy (Al-6063) processed by the friction stir processing technique. Samples of FSP-ed aluminium were examined and their microstructures, microhardness, Rockwell hardnesss and impact strength were studied and compared with base metal Al-6063. Hardness tester was employed to evaluate the interfacial bonding between the particles and matrix by indenting the hardness with the constant load and constant time. Impact test was employed to know the Impact Strength of samples against the Impact of Hammer.