TY - CHAP A1 - Naumov, Anton A1 - Chenikov, Evgenii V. A1 - Golubev, Iurii A1 - Michailov, Vesselin T1 - Numerical simulation and microstructure analysis of friction stir welded Al 6082 T2 - METAL 2015, 24th International Conference on Metallurgy and Materials, conference proceedings, June 3rd-5th 2015, Brno Y1 - 2015 SN - 978-80-87294-62-8 PB - Tanger CY - Ostrava ER - TY - GEN A1 - Naumov, Anton A1 - Isupov, Fedor A1 - Golubev, Iurii A1 - Morozova, Iuliia A1 - Spree, Cornelius T1 - Development of Methodology to Determine the Temperature Influence on Microstructure Evolution during Friction Stir Welding T2 - Papers from Materials Science and Technology 2018 (MS&T18), October 14–18, 2018, Greater Columbus Convention Center, Columbus, Ohio, USA Y1 - 2018 UR - https://www.researchgate.net/publication/328772948_DEVELOPMENT_OF_METHODOLOGY_TO_DETERMINE_THE_TEMPERATURE_INFLUENCE_ON_MICROSTRUCTURE_EVOLUTION_DURING_FRICTION_STIR_WELDING U6 - https://doi.org/10.7449/2018mst/2018/mst_2018_795_802 ER - TY - GEN A1 - Morozova, Iuliia A1 - Obrosov, Aleksei A1 - Naumov, Anton A1 - Królicka, Aleksandra A1 - Golubev, Iurii A1 - Bokov, Dmitry O. A1 - Doynov, Nikolay A1 - Weiß, Sabine A1 - Michailov, Vesselin T1 - Impact of Impulses on Microstructural Evolution and Mechanical Performance of Al-Mg-Si Alloy Joined by Impulse Friction Stir Welding T2 - Materials N2 - Impulse Friction Stir Welding (IFSW) was utilized to join 6082–T6 alloy plates at various impulse frequencies. A distinctive feature of IFSW is the generation of mechanical impulses that enhances the forging action of the tool, and thereby, alters the weld microstructure. The microstructural evolution in the Stir Zone (SZ) with special focus on the strengthening precipitation behavior, and overall mechanical properties of the IFSW joints have been investigated. It was demonstrated that the strengthening β″ precipitates reprecipitated in the SZ of the IFSW joints during natural aging. In contrast, no precipitates were found in the SZ of the Friction Stir Welding (FSW) weld. Partial reversion of β″ after IFSW is supposed to occur due to more developed subgrain network and higher dislocation density introduced by impulses that accelerated precipitation kinetics. Dynamic recrystallisation was facilitated by impulses resulting in a fine, homogeneous structure. There was no significant difference between the microhardness in the SZ, tensile and yield strength of the FSW and IFSW joints. However, the application of impulses demonstrated the smoothing of the hardness reduction in the transition region at the advancing side. The shift of the fracture location from the Heat-Affected Zone (HAZ) by FSW to the SZ as well as higher elongation of the joints by IFSW of lower frequencies could be related to the grain refinement and the change of the grain orientation. KW - Al-Mg-Si alloy KW - impulse friction stir welding (IFSW) KW - precipitation KW - microstructure evolution KW - mechanical properties Y1 - 2021 UR - https://www.mdpi.com/1996-1944/14/2/347/htm U6 - https://doi.org/https://doi.org/10.3390/ma14020347 SN - 1996-1944 VL - 14 IS - 2 ER - TY - GEN A1 - Naumov, Anton A1 - Morozova, Iuliia A1 - Rylkov, Evgenii A1 - Obrosov, Aleksei A1 - Isupov, Fedor A1 - Michailov, Vesselin A1 - Rudskoy, Andrey I. T1 - Metallurgical and Mechanical Characterization of High-Speed Friction Stir Welded AA 6082-T6 Aluminum Alloy T2 - Materials N2 - The objective of this study was to investigate the effect of the high welding speed on the mechanical properties and their relations to microstructural characteristics of butt friction stir welded joints with the use of 6082-T6 aluminum alloy. The aluminum sheets of 2.0 mm thick were friction stir welded at low (conventional FSW) and high welding speeds (HSFSW) of 200 and 2500 mm/min, respectively. The grain size in the nugget zone (NZ) was decreased; the width of the softened region was narrowed down as well as the lowest microhardness value located in the heat-affected zone (HAZ) was enhanced by HSFSW. The increasing welding speed resulted in the higher ultimate tensile strength and lower elongation, but it had a slight influence on the yield strength. The differences in mechanical properties were explained by analysis of microstructural changes and tensile fracture surfaces of the welded joints, supported by the results of the numerical simulation of the temperature distribution and material flow. The fracture of the conventional FSW joint occurred in the HAZ, the weakest weld region, while all HSFSW joints raptured in the NZ. This demonstrated that both structural characteristics and microhardness distribution influenced the actual fracture locations. KW - high-speed friction stir welding (HSFSW) KW - aluminum alloy KW - remnant oxide line (ROL) KW - microstructural characteristics KW - mechanical properties KW - fracture behavior KW - FEM Y1 - 2019 UR - https://www.mdpi.com/1996-1944/12/24/4211 U6 - https://doi.org/10.3390/ma12244211 SN - 1996-1944 VL - 12 IS - 24 ER - TY - CHAP A1 - Golubev, Iurii A1 - Morozova, Iuliia A1 - Naumov, Anton A1 - Hantelmann, Cord A1 - Doynov, Nikolay A1 - Michailov, Vesselin T1 - Numerical simulation and experimental investigation on Numerical simulation of 6082-T6 aluminum alloy T2 - Materials Science and Technology 2017, (MS&T17), Pittsburgh, Pennsylvania, USA, October 8-12, 2017, volume 2 N2 - The series of impulse friction stir welding (IFSW) experiments for aluminum alloy 6082-T6 butt joints was performed to obtain micrographs, tensile and hardness test samples and to receive the validation data for a numerical model of the process. Impulse force and frequency were varied to determine the effect of individual process parameters on microstructure evolution and mechanical properties of the welded butt joints. A three-dimensional model was established to simulate temperature distribution, heat generation and contact state between the tool and the workpiece during IFSW. Based on the numerical simulation, the influence of the impulses on heat input, maximum weld temperatures and contact state was found. The combination of impulse force and frequency effected the grain refinement. The influence of impulses on the elongation and hardness of the welded joints during IFSW were determined. KW - Aluminum alloy KW - Numerical simulation Y1 - 2017 SN - 978-1-5108-5058-3 SP - 987 EP - 994 PB - Curran Associates, Inc. CY - Red Hook, NY ER - TY - CHAP A1 - Golubev, Iurii A1 - Naumov, Anton A1 - Michailov, Vesselin T1 - Developing finite element model of the friction stir welding for temperature calculation T2 - METAL 2014, International Conference on Metallurgy and Materials, May 21 st - 23rd 2014, Brno Y1 - 2014 SN - 978-80-87294-54-3 SP - 1242 EP - 1248 ER - TY - CHAP A1 - Naumov, Anton A1 - Chenikov, Evgenii V. A1 - Golubev, Iurii A1 - Michailov, Vesselin T1 - Research of temperature distribution during friction stir welding of 2 mm Aw 6082 sheets T2 - METAL 2015, 24th International Conference on Metallurgy and Materials, conference proceedings, June 3rd-5th 2015, Brno Y1 - 2015 SN - 978-80-87294-62-8 SP - 651 EP - 653 PB - Tanger CY - Ostrava ER - TY - CHAP A1 - Golubev, Iurii A1 - Naumov, Anton A1 - Chernikov, Evgenii V. A1 - Michailov, Vesselin ED - Mishra, Rajiv S. ED - Mahoney, Murray W. ED - Sato, Yutaka ED - Hovanski, Yuri T1 - Temperature distribution and welding distortion measurements after FSW of Al 6082-T6 sheets T2 - Friction Stir Welding and Processing VIII, 144th Annual Meeting and Exhibition, 15.03.2015, Orlando Y1 - 2015 SN - 978-3-319-48604-8 SN - 978-3-319-48173-9 U6 - https://doi.org/10.1007/978-3-319-48173-9 SP - 289 EP - 295 PB - Springer CY - Cham ER - TY - GEN A1 - Naumov, Anton A1 - Morozova, Iuliia A1 - Isupov, Fedor A1 - Golubev, Iurii A1 - Michailov, Vesselin T1 - Temperature Influence on Microstructure and Properties Evolution of Friction Stir Welded Al-Mg-Si Alloy T2 - Key Engineering Materials N2 - The temperature influence on the microstructure evolution and microhardness of the agehardenable aluminium alloy 6082 T6 during friction stir welding was defined. In order to achieve this aim, the thermocycles calculated using the developed 3D Finite Element Model were physically simulated on the Gleeble-3800 in the points which located in the different zones of the weld. The microstructure in the chosen points after Gleeble testing was investigated as well as the microhardness was measured. The results were consequently compared with the relevant results obtained after friction stir welding. It was shown that the microstructure and microhardness profile are influenced not only by temperature but by deformation. The increase in hardness in different zones after FSW compared to Gleeble testing can be explained by the grain refinement in the nugget zone as well as the hardening precipitate distribution along the weld which can occur more rapidly due to the deformation influence. Y1 - 2019 U6 - https://doi.org/10.4028/www.scientific.net/KEM.822.122 SN - 1662-9795 VL - 822 SP - 122 EP - 128 ER - TY - GEN A1 - Naumov, Anton A1 - Isupov, Fedor A1 - Golubev, Iurii A1 - Morozova, Iuliia T1 - Effect of the temperature of friction stir welding on the microstructure and mechanical properties of welded joints of an Al-Cu-Mg alloy T2 - Metal Science and Heat Treatment N2 - Amethod for assessing the effect of the temperature of friction stir welding on the microstructure and mechanical properties of welded joints of aluminum alloy D16AT is suggested. The temperature cycles in different zones of a welded joint are determined by mathematical simulation. The computed temperature cycles are implemented in a Gleeble-3800 system. It is shown that the welding temperature affects little the evolution of the microstructure in different zones of the welded joints of alloy D16AT. Y1 - 2019 U6 - https://doi.org/10.1007/s11041-019-00342-0 SN - 1573-8973 SN - 0026-0673 VL - 60 SP - 695 EP - 700 ER -