A New Friction Stir Processing Method for Fabricating AZ91/SiC Nano-composite
M Taherishargh - MsC Student
N Parvin - Assistant Professor, Mining and Metallurgical Engineering Department
H Omidvar - Assistant Professor, Mining and Metallurgical Engineering Department
P Asadi - PhD student
In this investigation, a new method of friction stir processing (FSP) was applied to fabricate SiC/AZ91 composite layer. Current FSP methods suffer from inhomogeneous distribution of reinforcement particles in the processed area. Besides, they are unable to produce composite layer in a wide area. In this investigation, the SiC powder was packed into the grooves on AZ91 sheet perpendicular to the tool direction. The distance between the grooves centerline was 4mm and six-pass FSP with 2.5 mm overlap was carried out. Particles distribution, microstructure and hardness were evaluated on the surface and inside the processed area. Moreover, the wear characteristics of the resulted composite were evaluated using a pin-on-disc wear tester at room temperatures. It was found that the reinforcement particles were distributed uniformly inside the nugget zone and on the surface without any agglomeration taking place. The hardness and grain size of different points on the surface were almost constant. The microstructure and hardness of stirred zone (SZ) were homogeneous in longitudinal and transverse directions. The fabricated AZ91/SiC nanocomposite showed superior wear resistance to that of plain AZ91 alloy.
Friction stir processing; nanocomposite; SiC; AZ91; wear