Manufacturing Concept and Prototype for Train Component Using the FSW Process

Abstract

Friction stir welding (FSW) is a process originally developed for joining light materials, such as aluminum and magnesium, as an answer to their poor weldability by conventional fusion processes. In Colombia, the technique has been studied but its industrial implementation is uncommon, due to the high cost of specialized machinery and the unfamiliarity with the technique of local industries. This article presents an implementation case study of FSW on a 6082-aluminum alloy train component from Metro de Medellín (MdM), aiming to establish the component design changes required to accommodate the FSW process, and conventional machines available in the local area which may be available for welding. Additionally, a simple comparison was made between the cost of this approach versus the manufacturing strategy currently used for the selected component. Initially, welding forces were measured when performing the seam on the selected component using an FSW machine. This data was then used to downselect the local milling machines with these capabilities. A simple but specific tool was designed for the geometry of one of the component features. Finally, a prototype was fabricated, and weld samples were obtained, polished, etched, and examined using a microhardness machine and an optical microscope. Results show a good opportunity for the execution of simple components with uniform geometries, which can be carried out using locally available machinery because they do not surpass their maximum loading capacity, the welds do not present visible discontinuities, and an average hardness of 69.5 HV and mechanical efficiency of 95% can be achieved. Additionally, the manufacturing process is around 30% cheaper compared to traditional methods, making the application viable, economically speaking.

Variable Neighborhood Strategy Adaptive Search for Optimal Parameters of SSM-ADC 12 Aluminum Friction Stir Welding

“…A lot of research has been conducted on process parameters and their effects on FSW aluminum alloys. The process parameters for welding are important for control-ling heat generation, plastic deformation, material flow, material mixing, metallurgy, strength, and reducing defects [12][13][14][15][16][17][18][19][20][21][22][23][24]. Recent studies on the optimal process parameters for aluminum welding found that rotation speed, welding speed, shoulder diameter per pin diameter ratio, tool geometry, and surface shoulder can cause increases or decreases in the strength and number of weld line defects [25][26][27].…”

Evaluating Temperature Control in Friction Stir Welding for Industrial Applications

“…Initial implementations of FSW relied on skilled research teams to develop a specific welding parameter for a fixed tool and set of boundary conditions to achieve a desired output. While this approach has yielded many successful applications of the process, starting as early as 1995 [2][3][4][5], this approach adds to the cost of development and makes transitions from machine to machine problematic at best [6]. The difficulties associated with the development of new welding parameters and transferring parameters to different equipment is largely based on the coupled nature of interactions within a friction stir weld.…”

Effect of Processing Parameters on Strength and Corrosion Resistance of Friction Stir-Welded AA6082

“…It shows excellent machinability, good welding performances, and high corrosion resistance [16]. AA6082 alloy is widely used in the high-speed train industry, such as profiles and carriage components [17,18]. Conventional welding methods might lead to the formation of defects due to the change of state, such as poor solidification and porosity in the nugget zone.…”