Niğde Ömer Halisdemir Üniversitesi Mühendislik Bilimleri Dergisi

Yazarlar: Şefika KASMAN, Sertan OZAN

Konular:Mühendislik, Makine

DOI:10.28948/ngumuh.445390

Anahtar Kelimeler:Friction stir welding,Pin overlap,Mechanical properties,Microstructure

Özet: In this study, the changes in mechanical properties of AA-7075 T651 aluminum alloy plates for a fixed pin offset distance and two overlapping weld seams with two different offset directions were investigated. Comparisons were made with the mechanical properties of the single weld seam formed on the contact surface of the plates without any offset. In addition, microstructural observations of welded joints were carried out to investigate the defects in welded joints and the changes of grain structure in the nugget zone. As a result of evaluation of the experimental data, the highest tensile strength, 423 MPa, was obtained from the welded joint with single weld seam which was manufactured with a tool rotational speed of 400 rpm and without any pin overlap. The elongation at rupture for this condition was measured to be 10%, while the highest elongation at rupture, 12.5%, was obtained from the joint welded with a tool rotational speed of 400 rpm and where AS was selected as the pin offset direction. The highest strength and elongation at rupture (%) for all three different pin offset directions were obtained with the tool rotational speed of 400 rpm. It was revealed that with the increase in tool rotational speed, both tensile strength and elongation at rupture (%) decreased.

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