Investigation of Mechanical Properties and Weld nugget Characteristics of Thermoplastics by Using Friction Stir Welding with Heat Assisted Induction Coil

Friction stir welding (FSW) is a method of welding that creates a weld trail by pressing a non-consumable rotating tool with a profiled pin on the adjacent surfaces while moving transversely along the welding direction. The method was initially used with metals and alloys, but more recently, thermoplastic polymers have also been included in its application. Investigations on FSW of thermoplastic polymers made of nylon and High-density polythene (HDPE) are presented here. Weld characteristics that are like those of the base materials are attempted to be achieved. Because of their unique nature and thermal conductivity, thermoplastics FSW differs from that of metals. The use of thermoplastic materials with conventional FSW procedures presents numerous difficulties and is currently ineffective. On the weld characteristics of nylon and HDPE, statistical methods were utilized to study the impact of temperature, rotational speed, and transverse speed. Temperature is found to be the most important factor, followed by rotational and traversal speeds. In general, a higher temperature in combination with lower transverse speeds produced the most desirable results. Nylon exhibited a higher UTS of 35MPa when compared with HDPE which possess UTS of 16.7 MPa after friction stir welding under optimized process parameters with using induction assisted coil. A welding efficiency of 55% and 41% were observed for nylon and HDPE respectively based on their base material UTS. Microstructural aspects will also be discussed.