Effects of tool shoulder size on the thermal process and material flow behaviors in ultrasonic vibration enhanced friction stir welding

2020 ◽  
Vol 53 ◽  
pp. 69-83 ◽  
Author(s):  
L. Shi ◽  
C.S. Wu ◽  
L. Fu
Keyword(s):  
Friction Stir Welding ◽  
Ultrasonic Vibration ◽  
Material Flow ◽  
Thermal Process ◽  
Friction Stir ◽  
Tool Shoulder

scholarly journals The Effect of Tool Pin Size and Taper Angle on the Thermal Process and Plastic Material Flow in Friction Stir Welding

2021 ◽  
Author(s):  
Jie Chen ◽  
Lei Shi ◽  
Chuansong Wu ◽  
Yuanning Jiang
Keyword(s):  
Friction Stir Welding ◽  
Shear Layer ◽  
Layer Thickness ◽  
Material Flow ◽  
Horizontal Plane ◽  
Thermal Process ◽  
Plastic Material ◽  
Taper Angle ◽  
Friction Stir ◽  
Tool Pin

Abstract Friction stir welding (FSW) tool pin, as a critical component of FSW tool, plays an important role in determining the final joint properties by affecting the heat generation, plastic material flow, welding loads and so on. However, the influence of tool pin on heat and mass transfer in FSW are not elucidated. In the present study, a validated model was adopted to quantitatively analyze the effects of pin size and taper angle on the thermal process and plastic material flow in FSW. It reveals that the torque and transverse force imposed on the pin are increased with the increase of the pin diameters (including its root diameter, its tip diameter and its size in condition of constant taper angle), while the total tool torque various a little for the tool pin diameter considered in this study. When the pin diameters increase, the viscosity of the materials near the pin is decreased, while the temperature as well as the flow velocity is increased. More plastic material near the tool could rotate around the tool with an increase of the pin diameter. The TMAZ boundary is enlarged with larger pin diameters in FSW. Particularly, the shear layer thickness of the same horizontal plane in the range of 1 mm < z < 5 mm is significantly enlarged with an increase of pin root diameters. However, the shear layer thickness of the same horizontal plane in the region of z < 5 mm is increased when using a larger pin tip diameter. In addition, maximum width of TMAZ boundary at the top surface of workpiece was not affected by pin diameters. The model is validated by experimental results. It lays solid foundation for optimizing the tool pin size and taper angle in FSW.

scholarly journals Temperature Monitoring and Material Flow Characteristics of Friction Stir Welded 2A14-t6 Aerospace Aluminum Alloy

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3387 ◽  
Author(s):  
Tingke Wu ◽  
Fengqun Zhao ◽  
Haitao Luo ◽  
Haonan Wang ◽  
Yuxin Li
Keyword(s):  
Friction Stir Welding ◽  
Material Flow ◽  
Flow Model ◽  
Welding Process ◽  
Temperature Monitoring ◽  
Measuring System ◽  
Welding Parameters ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Tool Pin

Aiming at the problems that the temperature in the welding area of friction stir welding (FSW) is difficult to measure and the joints are prone to defects. Hence, it is particularly important to study the material flow in the welding area and improve the welding quality. The temperature of the tool shoulder and the tool pin was monitored by the wireless temperature measuring system. The finite element model of friction stir welding was established and the welding conditions were numerically simulated. The flow law of material of the friction stir welding process was studied by numerical simulation. The material flow model was established by combining the microstructure analysis results, and the forming mechanism of the defects was analyzed. The results show that the temperature in the welding zone is the highest at 1300 rpm, and the temperature at the tool shoulder is significantly higher than that at the tool pin in the welding stage. When high-rotation speeds (HRS) are chosen, the material beneath the tool shoulder tends to be extruded into the pin stirred zone (PSZ) after flowing back to the advancing side. This will cause turbulence phenomenon in the advancing side of the joint, which will easily lead to the formation of welding defects. In the future, temperature monitoring methods and the flow model of material can be used to optimize the welding parameters.

Metallurgical Nature at the Interface between Tool Shoulder and Workpiece during Friction Stir Welding

2007 ◽  
Vol 29-30 ◽  
pp. 43-46
Author(s):  
Zhan W. Chen ◽  
Timotius Pasang ◽  
Q. Yin ◽  
R. Peris
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloys ◽  
Material Flow ◽  
Intermetallic Layer ◽  
Contact Condition ◽  
Sliding Contact ◽  
Metallographic Examination ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Fsw Experiments

Knowledge on the contact condition at the tool/workpiece interface is essential for understanding many aspects of FSW. In the present study, FSW experiments were conducted using aluminium alloys followed by metallographic examination focusing on the tool shoulder-workpiece interface region. It was observed that an interfacial intermetallic layer and hence metallurgical sticking/soldering readily formed. Temperature measurements have suggested the presence of interface liquid, hence suggesting a mechanical sliding contact condition dominant. This has been supported by the observation on material flow within the shear layer.

Material flow and mechanical properties of friction stir welded Al-Mg-Si alloy: Role of concentric circles shoulder with non-circular pins

2021 ◽  
pp. 095440622198939
Author(s):  
Krishna Kishore Mugada ◽  
Kumar Adepu
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Heat Input ◽  
Material Flow ◽  
Process Conditions ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Average Hardness ◽  
Concentric Circles

Understanding the material flow in friction stir welding (FSW) is one of the challenging aspects for producing defect free and quality welds. The material flow is majorly governed by the tool shoulder/pin geometries and process conditions. In the present study, concentric circles shoulder shape with various polygonal pin designs are selected, and their influence on material flow and mechanical properties in Al 6082 friction stir welds is addressed. Material flow is studied by inserting the markers before welding and subsequent analysis of deformed marker material by radiography and macrostructure after welding. The outcome shows the welds with square pin design facilitated a constant stable force, and hexagonal pin design facilitated a decreasing behavior of force with reference to welding length/time. The heat input is increasing from triangular pin to hexagonal pin and is maximum for welds with hexagonal pins (973 kJ/mm). Further, welds with hexagonal pins (TCC)HEX tool facilitated higher mechanical properties of strength (187 MPa) and average hardness (79 HV) at the stir zone.

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