Experimental studies of parameters affecting the heat generation in friction stir welding process

Abstract

Heat generation is a complex process of transformation of a specific type of energy into heat. During friction stir welding, one part of mechanical energy delivered to the welding tool is consumed in the welding process, another is used for deformational processes etc., and the rest of the energy is transformed into heat. The analytical procedure for the estimation of heat generated during friction stir welding is very complex because it includes a significant number of variables and parameters, and many of them cannot be fully mathematically explained. Because of that, the analytical model for the estimation of heat generated during friction stir welding defines variables and parameters that dominantly affect heat generation. These parameters are numerous and some of them, e. g. loads, friction coefficient, torque, temperature, are estimated experimentally. Due to the complex geometry of the friction stir welding process and requirements of the measuring equipment, adequate measuring configurations and specific constructional solutions that provide adequate measuring positions are necessary. This paper gives an overview of the process of heat generation during friction stir welding, the most influencing parameters on heat generation, constructional solutions for the measuring equipment needed for these experimental researches and examples of measured values

Analytical Model for Estimating the Amount of Heat Generated During Friction Stir Welding: Application on Plates Made of Aluminium Alloy 2024 T351

“…Figure 17. a) Temperature distribution in workpieces in plane normal to the joint line, b) temperature history (experimental and numerical) of specific discrete nodes, c) location of selected discrete nodes [56,57] Figure 16, a gives a rendered image of numerically estimated temperature in workpieces. Rendering is done for the moment the temperature reached maximal value -a few seconds before the tool shoulder was involved in the welding process.…”

Fine tuning of dwelling time in friction stir welding for preventing material overheating, weld tensile strength increase and weld nugget size decrease

“…The first phase of the research consisted of a number of experiments performed to isolate and prove the optimal dimensions and shape of a welding tool, usable welding process parameters, as well as investigation of parameters affecting the heat generation process. Welding was performed on the universal lathe and due to the complexity of the research, it was necessary to have two different measuring configurations [25,41]. The first configuration was used for capturing loads on the welding tool and base material (forces and torque) while the second configuration was used to estimate friction coefficient and contact pressure between the welding tool and base material.…”

Temperature fields in linear stage of friction stir welding: Effect of different material properties

“…For example, Boeing applies FSW for the production of fuel tanks for Delta rockets, while Marine Aluminium from Norway uses this technique for joining large parts for ferry boats. Numerous studies of producing and testing of FSW joints can be found in the literature [2][3][4][5][6][7][8][9][10][11][12][13]. Regarding the joint geometry, butt joints are most often used in practice and analysed in the literature, e. g. [6,7,11].…”