بررسي ريز ساختار و خواص مكانيكي نانو كامپوزيت سطحي Al6061/Al2O3 توليد شده به روش فراوري اصطكاكي اغتشاشي

Investigation of microstructure and mechanical properties Al6061/Al2O3 surface nano composite fabricated via friction stir processing

در اين پژوهش به بررسي اثر تعداد پاس بر ريزساختار و مكانيكي آلياژ آلومينيم 6061 به همراه نانو ذرات آلومينا در اثر فرآيند اصطكاكي اغتشاشي پرداخته شده است. براي رسيدن به اين هدف نمونه¬ها به ترتيب در سرعت¬¬هاي دوراني و پيشروي 800 دور بر دقيقه و 28 ميليمتر بر دقيقه با زاويه انحراف 3 درجه در تعداد پاس¬هاي مختلف توليد شدند. نانو كامپوزيت توليد شده به منظور بررسي ريز ساختار از ميكروسكوپ الكتروني گسيل ميداني و نوري استفاده شد. براي بررسي خواص مكانيكي كامپوزيت توليد شده آزمون¬هاي ميكروسختي و كشش استفاده شد. نتايج نشان دادند با اضافه كردن نانو ذرات آلومينا و افزايش تعداد پاس ميزان سختي، استحكام كششي و ريزدانگي نمونه¬ها به ميزان چشمگيري بهبود مي¬يابد.

Abstract In this research, the weld properties of the composite plates of Al 356 matrix reinforced with SiC particles with the average particle size of 5 um which were fabricated by the stir casting method and were welded by the friction stir welding process were investigated. For performing the friction stir welding process, the rotational speed of 1000 rpm and the traverse speed of 30 mm/min were used. For microstructural investigation of the samples, optical and scanning electron microscopes were employed. In addition, for studying the mechanical properties, tensile and microhardness as well as wear tests were conducted and the results showed that hardness, tensile strength and wear of the welded samples were improved compared with those of the base metal and the composite. Considering the obtained results from the tests on the weld-joint, it can be concluded that the conducted friction stir welding was of a high quality.