Utilizing Ultrasonic Thermometry to Monitor Friction Stir Welding Temperature Profiles

2018 ◽  
Author(s):  
Z. Myers ◽  
J. Schneider ◽  
D. Yuhas
Keyword(s):  
Friction Stir Welding ◽  
Temperature Profiles ◽  
Welding Temperature ◽  
Friction Stir

scholarly journals Microstructural Evolutions of 2N Grade Pure Al and 4N Grade High-Purity Al during Friction Stir Welding

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3606
Author(s):  
Tomoya Nagira ◽  
Xiaochao Liu ◽  
Kohasaku Ushioda ◽  
Hidetoshi Fujii
Keyword(s):  
Friction Stir Welding ◽  
Dynamic Recrystallization ◽  
Grain Refinement ◽  
High Purity ◽  
Cube Texture ◽  
Grain Structure ◽  
Welding Temperature ◽  
Friction Stir ◽  
Continuous Dynamic Recrystallization ◽  
Dislocation Annihilation

The grain refinement mechanisms along the material flow path in pure and high-purity Al were examined, using the marker insert and tool stop action methods, during the rapid cooling friction stir welding using liquid CO2. In pure Al subjected to a low welding temperature of 0.56Tm (Tm: melting point), the resultant microstructure consisted of a mixture of equiaxed and elongated grains, including the subgrains. Discontinuous dynamic recrystallization (DDRX), continuous dynamic recrystallization (CDRX), and geometric dynamic recrystallization are the potential mechanisms of grain refinement. Increasing the welding temperature and Al purity encouraged dynamic recovery, including dislocation annihilation and rearrangement into subgrains, leading to the acceleration of CDRX and inhibition of DDRX. Both C- and B/-type shear textures were developed in microstructures consisting of equiaxed and elongated grains. In addition, DDRX via high-angle boundary bulging resulted in the development of the 45° rotated cube texture. The B/ shear texture was strengthened for the fine microstructure, where equiaxed recrystallized grains were fully developed through CDRX. In these cases, the texture is closely related to grain structure development.

scholarly journals Effect of Trailing Intensive Cooling on Residual Stress and Welding Distortion of Friction Stir Welded 2060 Al-Li Alloy

2018 ◽  
Vol 37 (5) ◽  
pp. 397-403 ◽  
Author(s):  
Shude Ji ◽  
Zhanpeng Yang ◽  
Quan Wen ◽  
Yumei Yue ◽  
Liguo Zhang
Keyword(s):  
Residual Stress ◽  
Friction Stir Welding ◽  
Plastic Strain ◽  
Welding Process ◽  
Butt Joint ◽  
Welding Distortion ◽  
Welding Temperature ◽  
Friction Stir ◽  
Numerical Simulation Methods ◽  
Conventional Cooling

AbstractTrailing intensive cooling with liquid nitrogen has successfully applied to friction stir welding of 2 mm thick 2060 Al-Li alloy. Welding temperature, plastic strain, residual stress and distortion of 2060 Al-Li alloy butt-joint are compared and discussed between conventional cooling and trailing intensive cooling using experimental and numerical simulation methods. The results reveal that trailing intensive cooling is beneficial to shrink high temperature area, reduce peak temperature and decrease plastic strain during friction stir welding process. In addition, the reduction degree of plastic strain outside weld is smaller than that inside weld. Welding distortion presents an anti-saddle shape. Compared with conventional cooling, the reductions of welding distortion and longitudinal residual stresses of welding joint under intense cooling reach 47.7 % and 23.8 %, respectively.

scholarly journals Microstructural Characteristics and Mechanical Properties of Water Cooling Bobbin-Tool Friction Stir Welded 6063-T6 Aluminum Alloy

2018 ◽  
Vol 206 ◽  
pp. 03002 ◽  
Author(s):  
Yunqiang Zhao ◽  
Chungui Wang ◽  
Chunlin Dong
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Water Mist ◽  
Water Cooling ◽  
Microstructural Characteristics ◽  
Welding Temperature ◽  
Weld Formation ◽  
Friction Stir ◽  
Mist Cooling

In this study, a novel welding method called water cooling bobbin-tool friction stir welding (WBT-FSW) was developed. 4 mm-thick 6063-T6 aluminum alloy sheets were successfully jointed by WBT-FSW. Comparative studies on macro/microstructural characteristics and mechanical properties of the WBT-FSW and conventional bobbin-tool friction stir welding (BT-FSW) joints were carried out. The results indicated that the water mist cooling can significantly decrease the welding temperature and improve both the weld formation and the mechanical properties of the joint. The tensile strength of the WBT-FSW joint was 11.4% higher than that of BT-FSW joint.

Analysis of tool wear and deformation in friction stir welding of unequal thickness dissimilar Al alloys

2020 ◽  
pp. 146442072097176
Author(s):  
Tanveer Majeed ◽  
Yashwant Mehta ◽  
Arshad Noor Siddiquee
Keyword(s):  
Friction Stir Welding ◽  
Tool Wear ◽  
Tilt Angle ◽  
Dissimilar Materials ◽  
Welding Temperature ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Process Forces ◽  
Wide Range ◽  
Lower Tool

Friction stir welding between plates of unequal thickness, which are made from similar or dissimilar materials, finds wide range of applications in the aerospace and automotive sectors. Friction stir welding of plates made from dissimilar materials having unequal thicknesses is challenging. One of the major challenges is the control of rapid tool degradation which occurs during welding. This work reports a maiden study on tool degradation of high thickness ratio unequal thickness dissimilar material joints made between 6.3 mm thick AA2024-T3 and 2.5 mm thick AA7475-T7 plates. The degradation of friction stir welding tool made of T4 tool steel having tapered cylindrical pin and scrolled shoulder was analyzed. The geometry of tool (before and after welding) was compared; the degradation was categorized, characterized, and analyzed in the light of measured welding temperature, process forces, and process parameters. It was found that the pin undergoes significant degradation in the form of wear and deformation compared to the tool shoulder. The experimental results demonstrated that lower flow stresses caused by higher process temperature leads to lower tool wear and deformation, and vice versa. In addition to temperature and process forces, the surface tilt angle was found to significantly affect the pin deformation. The higher surface tilt angle caused an increase in tool wear and deformation.

Improved Recrystallization Resistance and Welding Properties of Cold-Rolled Al-Mg Alloy Sheets by Microalloying with Sc and Zr

2021 ◽  
Vol 1035 ◽  
pp. 17-24
Author(s):  
Hao Wu ◽  
Zhi Kai Zheng ◽  
Si Meng Ren ◽  
Shu Lei Li ◽  
Hu Wang ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Welded Joints ◽  
Alloy Sheet ◽  
Mg Alloy ◽  
Softening Effect ◽  
Welding Temperature ◽  
Friction Stir ◽  
Alloy Increase ◽  
Welding Properties ◽  
Zr Alloy

The effects of Sc and Zr element on the recrystallization behavior and microstructure evolution of Al-Mg alloy had been researched in this paper, and meanwhile, the microstructure and mechanical properties of the friction stir welding joints were also analyzed. The results show that the recrystallization and grain growth behavior of Al-Mg-Sc-Zr alloy can be inhibited effectively by microalloying with Sc and Zr. Compared with Al-Mg and Al-Mg-Zr alloys, the recrystallization start temperature and finish temperature of Al-Mg-Sc-Zr alloy increase significantly, and the strength of alloy sheet which subjected to stabilizing annealing is increased by more than 50MPa. Moreover, the recrystallization softening effect of the welded joints microstructure, which caused by the welding temperature field and welding heat input, can be weaken by microalloying with Sc and Zr, the width of recrystallization zone is reduced, the microstructure and properties of the welded joints are improved. The friction stir welding coefficients of Al-Mg-Sc-Zr alloy increases to 86.9%.

scholarly journals Microstructural Characterization and Mechanical Properties of Similar and Dissimilar Al Alloys Joined using Friction Stir Welding

2018 ◽  
Vol 14 (1) ◽  
pp. 19-28
Author(s):  
Kharia Salman Hassan
Keyword(s):  
Friction Stir Welding ◽  
Welding Speed ◽  
Shot Peening ◽  
Rotational Speed ◽  
Microstructural Characterization ◽  
Tensile Tests ◽  
Welding Parameters ◽  
Welding Temperature ◽  
Rotating Speed ◽  
Friction Stir

The influence of pre- shot peening and welding parameters on mechanical and metallurgical properties of dissimilar and similar aluminum alloys AA2024-T3 and AA6061-T6 joints using friction stir welding have been studied. In this work, numbers of plates were equipped from sheet alloys in dimensions (150*50*6) mm then some of them were exposed to shot peening process before friction stir welding using steel ball having diameter 1.25 mm for period of 15 minutes. FSW joints were manufactured from plates at three welding speeds (28, 40, 56 mm/min) and welding speed 40mm/min was chosen at a rotating speed of 1400 rpm for welding the dissimilar pre- shot plates. Tow joints were made at rotational speed of 1000 rpm and welding speed of 40m/min from shot and without shot peening plats. Welding temperature was measured in three zones using thermocouple. Micro hardness (HV) and tensile tests were performed to evaluate the mechanical characteristic of the joints. The results show a decay in mechanical qualities when the welding speed was increased and the best result was at (28) mm/min and the opposite result was obtained when rotational speed increased and pre-shot contributed in improving of this decay at 88% of welding speed (40) mm/min and 98%  at the rotational speed of 1000 rpm.      

scholarly journals A Multi Scale Strategy for Simulation of Microstructural Evolutions in Friction Stir Welding of Duplex Titanium Alloy

2019 ◽  
Vol 38 (2019) ◽  
pp. 485-497 ◽  
Author(s):  
Z. Zhang ◽  
Z. J. Tan
Keyword(s):  
Friction Stir Welding ◽  
Volume Fraction ◽  
Average Length ◽  
Transformation Model ◽  
Scale Model ◽  
Welding Temperature ◽  
Rotating Speed ◽  
Friction Stir ◽  
Multi Scale ◽  
Translational Speed

AbstractA fully coupled thermo-mechanical model is established to simulate the temperature variations and the material deformations in friction stir welding (FSW) of Ti-6Al-4V. The extracted data are used for further simulation on microstructural evolutions. A multi scale model, which consists of the grain growth model in grain cluster scale and the phase transformation model in one grain scale, is proposed. The nuclei of α and β phases, the recrystallizations and the grain growths are systematically investigated. Comparisons with experimental data and experimental observations can validate the newly proposed microstructural evolution model for Ti-6Al-4V. Results indicate that the volume fractions of α and β phases can be directly determined by the cooling rates in FSW process. With the increase of the rotating speed, the volume fraction of α phase is increased and β phase decreased due to the increase of welding temperature. With the decrease of the translational speed, the volume fraction of α phase gets bigger and β phase smaller. The acicular α grain can be generated on the β grain boundaries and grows along <1 1 0> direction on β substrate. The average length of α grain can be increased with longer cooling time and decreased with lower rotating speed or higher translational speed.

scholarly journals Thermal Dissipation Effect on Temperature-controlled Friction Stir Welding

2019 ◽  
Vol 24 ◽  
Author(s):  
Ana Magalhães ◽  
Jeroen De Backer ◽  
Gunnar Bolmsjö
Keyword(s):  
Friction Stir Welding ◽  
Temperature Control ◽  
Tensile Tests ◽  
Fast Response ◽  
Lap Joints ◽  
Thermal Dissipation ◽  
Welding Parameter ◽  
Weld Quality ◽  
Welding Temperature ◽  
Friction Stir

Abstract During Friction Stir Welding (FSW) of complex geometries, the thermal dissipation, induced by geometric features or the surrounding environment, may strongly affect the final weld quality. In order to guarantee a consistent weld quality for different conditions, in-process welding parameter adaptation is needed. This paper studies the effect of thermal dissipation, induced by the backing bar thermal conductivity, on the weld temperature and the temperature controller response to it. A new temperature sensor solution, the Tool-Workpiece Thermocouple (TWT) method, was applied to acquire online temperature measurements during welding. An FSW-robot equipped with temperature control, achieved by rotation speed adaptation, was used. AA7075-T6 lap joints were performed with and without temperature control. The cooling rate during welding was register plus macrographs and tensile tests were assessed. The controller demonstrated a fast response promoting the heat input necessary to maintain the set welding temperature. The results demonstrated that temperature control using the TWT method is suitable to achieve higher joint performance and provides a fast setup of optimal parameters for different environments.

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