چكيده به لاتين
Nowadays, multilayer sheets possess various applications in the industry due to their mechanical and metallurgical properties. Nevertheless, joining these type of sheets would be absolutely challenging and usually is not possible using traditional welding processes. Hence, Friction Stir Welding (FSW) could be a reasonable and applicable choice in order for these multilayer sheets to be joined together. In present thesis, the effects of different parameters on FSW process of Cu-Al two-layer sheet have been considered. These parameters contain rotational speed and feeding rate of the tool, the tool geometry, tool entering side and the number of welding passes. Besides, the effects of these parameters on mechanical and metallurgical properties of welded region have been analyzed. In order to investigate the welding bond behavior, three feeding rates, two different rorational speed, three tool geometries, different welding passes, and two possible entering sides have been considered as altering and effective parameters. SEM images have been used to assess the intermetalic phases in the welding bond. Metalographical tests have been implemented to be informed about the micrcostructural and grain sizes. Moreover, tensile and microhardness tests were performed to declare the mechanical properties of the welded regions. Eventually, the results showed that the best mechanical property has been obtained for the sample having conical tool, one pass of welding, entering the tool from Cu side and having 800 rpm and 12 mm/min rotational speed and feeding rate, respectively.
Keywords: Friction Stir Welding, Two-layer sheets, Welding parameters, Mechanical properties, Metallurgical properties.
