Issue 54

I. Chekalil et alii, Frattura ed Integrità Strutturale, 54 (2020) 153-168; DOI: 10.3221/IGF-ESIS.54.11

Experimental profile Predicted profile

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Figure 18: Predicted and experimental values of the stress-strain curve

C ONCLUSIONS

T

his work focuses on the friction stir welding (FSW) process of aluminum 3003. This study mainly concentrates on the influence of three parameters, namely rotational speed, feed rate and tool tilt angle. The main purpose of this investigation was to understand and explain the interactions between the three parameters mentioned above, and to highlight the influence of each one of them on the others. The mechanical properties, such as the yield stress, ultimate tensile stress, and rupture strength, of the joints were studied in this context. A mathematical model is proposed to predict the mechanical behavior of the junction using response surface methodology (RSM). This model is used to determine the optimal values of these parameters that are responsible for the better performance of the FSW joint. Optimization of the welding process parameters suggests that:  The tensile properties of friction stir-welded joints remain relatively good. In addition, the findings indicate that rupture most often takes place near the thermo-mechanically affected zone (ZATM). The most influential parameters are in the order of the rotational speed, feed rate and tool tilt angle.  The model developed by the Design of Experiments approach made it possible to obtain a better prediction of the mechanical behavior of a welded joint. This model provides an effective tool for selecting the optimal parameters of the friction stir welding (FSW) process.  The optimized parameter values that allow obtaining the best mechanical properties of a welded joint correspond to the values of 1423.93 / N rot min  , 400 / S mm min  and 1.2885 T   .  The combinations of the different factors for a better quality of the FSW joint by obtaining a tensile strength of the weld joint equal to 75% of that of the base metal. In continuing the development of these projects. It is interesting to study the effect of these parameters on expected heat input, temperature and material flow.

R EFERENCES

[1] Pashazadeh, H., Teimournezhad, J., Masoumi, A. (2017). Experimental investigation on material flow and mechanical properties in friction stir welding of copper sheets, Int. J. Adv. Manuf. Technol., 88(5–8), pp. 1961–1970. https://doi.org/10.1007/s00170-016-8913-9. [2] Palanivel, R., Mathews, P.K., Murugan, N., Dinaharan, I. (2012). Effect of tool rotational speed and pin profile on microstructure and tensile strength of dissimilar friction stir welded AA5083-H111 and AA6351-T6 aluminum alloys, Mater. Des., 40, pp. 7–16. http://dx.doi.org/10.1016/j.matdes.2012.03.027.

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