In this study, the effect of tool rotation speed on the mechanical and metallurgical properties of friction stir spot welded (FSSW) AA7075-T6 aluminum alloy sheets was investigated. Aluminum alloy plates were joined by FSSW using welding parameters consisting of three different rotation speeds of 1040, 1320 and 1500 rpm and a constant insertion depth of 3.2 mm. In spot welded specimens, the highest tensile strength value (6200 N) was obtained in plates welded at a tool rotation speed of 1500 rpm. The data obtained from the metallographic analysis are compatible with the tensile test results. Metallographic investigations demonstrated that there was a small amount of porosity in the welding zone of the specimens jointed at 1500 rpm.

The scope of the study focused on tool speeds-plate temperatures at joining aluminium alloy and copper plates. The AA7075-T6 aluminium alloy and pure copper were welded using friction-stir welding (FSW) technique. The temperature variations of plates from stirred zone were detected using thermocouples installed at equal distance on both sides of the axis of the pin linear displacement. The temperature distribution in the surroundings of the welded zone was investigated. The effects of tool rotational speeds on plate temperatures were determined using such welding parameters of three tool rotational speeds of 660, 920 and 1500 rpm at a constant welding speed of 32 mm/min.

Yaş kimyasal yöntem ile bor katkılı hidroksiapatit üretimi  Bor katkısının yapısal ve mekanik özellikler üzerindeki etkisi  Sinterleme işleminin bor katkılı hidroksiapatit eldesi üzerindeki etkisi

Friction stir welding frequently produces a superior microstructure and mechanical properties than conventional methods for welding nonferrous materials and alloys. In this study, friction stir welding was used to join sheets of the aluminum alloy AA7075 with commercially pure copper cpCu. Two rotational speeds, 660 and 920 rpm, and three welding speeds, 18, 32 and 54 mm × min−1, were studied to determine the effects of these parameters on the structure and mechanical properties of friction stir welded AA7075-cpCu. The joint performance was investigated by conducting optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), by microhardness measurements and mechanical testing (e. g. tensile tests). A maximum tensile strength of 224 MPa and percentage elongation of 2.49 were obtained when friction stir welding process parameters, namely rotational speed and welding speed, were kept at 660 rpm and 32 mm × min−1, respectively.

DP600 steel and AA7075-T6 aluminium alloy plates were joined using the friction stir spot welding process. The effects of different tool rotational speeds on the mechanical properties, intermetallic compound formation and interface microstructure of welded joints were investigated. The highest lap shear tensile load was obtained from the samples joined at a rotational speed of 1040 rpm (6.5 kN). It was determined that the tensile load of the welded joint decreased with increasing tool rotational speed. XRD analysis performed on broken surfaces, the intermetallic phase was determined to be Al13Fe4. As a result of Vickers microhardness tests, the samples joined at 1320 rpm and 1500 rpm, in the structure of which intermetallic compounds were determined by XRD analysis, displayed higher hardness values. In addition, when scanning electron microscope images were examined, it was determined that the cracks observed in the samples and the porosity both increased with increasing tool rotational speed.