Experimental investigation of friction stir spot welding of polymer-aluminum alloy weldments

Abstract

The friction stir spot welding (FSSW) process is one of the main solid-state joining methods used widely for welding different materials and dissimilar metals. In this article, the welding of Polytetrafluoroethylene (PTFE) and aluminum alloy sheets by the FSSW process will be investigated experimentally. The joining of polymer (PTFE) and metal (AA1050 aluminum alloy) was done successfully. The effect of process parameters including tool rotational speed, penetration depth, initial holding time, dwell time, and tool shoulder diameter on the joint strength and elongation of the weldments will be studied using response surface methodology (RSM). The joint strength was increased by creating a threaded hole in the aluminum sheet. A mechanical lock was created between the softened PTFE and the edge of the threaded hole. The shear-tensile tests have been carried out for 32 designed experiments. The results show that the joint strength increased by increasing the initial holding time due to the better wettability of PTFE and aluminum sheet. The joint strength increased by increasing the tool rotational speed and tool diameter (better pouring of the hole and formation of the mechanical lock). Two different fracture modes have been observed in the samples: (1) fracture in the peripheral area of the joint (partial interfacial fracture mode) and (2) fracture in the mechanically locked area (pull-out mode with tearing).

Differentiation in the SiC Filler Size Effect in the Mechanical and Tribological Properties of Friction-Spot-Welded AA5083-H116 Alloy

“…Pereira et al [50] and Ramesh Rudrapati [51] reported in their reviews that further investigations and research are required to find the appropriate plunge force, temperature, fiber fragmentation degree, tilt angle, tool geometry, and rotational speed for conducting FSW on polymer composites. Jalal Joudaki et al [52] successfully demonstrated the FSW of polymer-AA 1050 (PTFE-Al) composites. Innovations in the current method for fabricating composite FSSW joints provides an ideal framework for fabricating reinforced polymer/polymer matrix composite spot joints to reduce costs and improve productivity, with low environmental impacts, in the aerospace, automobile, and electronic device industries.…”

“…Pereira et al [50] and Ramesh Rudrapati [51] reported in their reviews that further investigations and research are required to find the appropriate plunge force, temperature, fiber fragmentation degree, tilt angle, tool geometry, and rotational speed for conducting FSW on polymer composites. Jalal Joudaki et al [52] successfully demonstrated the FSW of polymer-AA 1050 (PTFE- With the understanding that nano-SiC-reinforced AA5083-H116 joints have higher weld strength than AA5083-H116-only joints, this research methodology can be extended to other materials. In recent years, there has been increased research interest in fabricating polymer joints through the FSW/FSSW processes [50][51][52].…”

“…Jalal Joudaki et al [52] successfully demonstrated the FSW of polymer-AA 1050 (PTFE- With the understanding that nano-SiC-reinforced AA5083-H116 joints have higher weld strength than AA5083-H116-only joints, this research methodology can be extended to other materials. In recent years, there has been increased research interest in fabricating polymer joints through the FSW/FSSW processes [50][51][52]. Pereira et al [50] and Ramesh Rudrapati [51] reported in their reviews that further investigations and research are required to find the appropriate plunge force, temperature, fiber fragmentation degree, tilt angle, tool geometry, and rotational speed for conducting FSW on polymer composites.…”

“…Pereira et al [50] and Ramesh Rudrapati [51] reported in their reviews that further investigations and research are required to find the appropriate plunge force, temperature, fiber fragmentation degree, tilt angle, tool geometry, and rotational speed for conducting FSW on polymer composites. Jalal Joudaki et al [52] successfully demonstrated the FSW of polymer-AA 1050 (PTFE-…”

Butted friction stir forming of AA6061-T6 to low carbon steel

“…FSW expands on the possibilities of dissimilar material combinations by joining workpieces that are difficult or impossible to perform with more traditional methods. Previous FSW research shows joinable dissimilar material pairs, such as metals, 2–7 polymers, 8 and composites. 9,10 Traditional and derivative FSW processes can weld this wide range of materials.…”