Effect of Processing Parameters on the Microstructure an‎d Mechanical Properties of AA6061–Al2O3 Composite Produced by Extrusion

10/15/2026 12:00:00 AM

AA6061 metal matrix composites reinforced with Al₂O₃ particles are widely used in the aerospace an‎d automotive industries due to their high strength-to-weight ratio, making the optimization of hot extrusion parameters essential for achieving superior microstructure an‎d mechanical performance. This study provides a comprehensive investigation into the effects of the two main hot extrusion parameters extrusion ratio an‎d extrusion temperature on the microstructure an‎d mechanical properties of AA6061–Al₂O₃ composites. Composite samples were fabricated through billet preparation, Al₂O₃ powder deposition, an‎d hot extrusion, using a two-factor, three-level experimental design with extrusion ratios of 6, 13, an‎d 18 an‎d temperatures of 300°C, 350°C, an‎d 400°C. Post-extrusion analyses included optical an‎d electron microscopy, particle distribution assessment via EDS, an‎d Brinell hardness testing. The highest average hardness (61 HB) occurred at an extrusion ratio of 6 an‎d a temperature of 350°C, while increasing the ratio to 18 an‎d the temperature to 400°C reduced hardness due to dominant dynamic softening processes such as recrystallization. Microstructural an‎d EDS results revealed a non-uniform distribution of Al₂O₃ nanoparticles, with increasing concentration from the initial toward the middle an‎d end regions of the extruded samples, accompanied by a noticeable hardness gradient along the specimen length

اكستروژن گرم , نسبت اكستروژن , ريز ساختار

hot extrusion , extrusion raito , micro structure

Hosein Mohammad Bagheri

Dr. Bagher Mohammad Sadeghi, Dr. Seyed Hossein Razavi