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Strength of Weldments
Published in Joseph Datsko, Materials Selection for Design and Manufacturing, 2020
The second type, mechanical plus thermal, contains both the oldest and the newest of the welding processes. Undoubtedly the oldest welding process is the forge welding process, where the pieces to be joined have been heated in an open fire or “forge,” and then the ends to be joined are placed, one on top of the other, on an anvil and and hammered (or forged) together. Early practitioners of this trade developed considerable skill in the joining of bars or plates of iron. Because of the limitations in the size of castings and forgings that could be produced, whenever large parts were required, it was necessary to employ the forge welding process. Welding artisans achieved surprisingly good welds by first crowning or beveling the mating surfaces to facilitate squeezing out the oxides. By throwing silica sand onto the areas to be welded, they converted the iron oxide to a more fluid slag, which aided its expulsion from the interface.
Sustainability in Joining
Published in R. Ganesh Narayanan, Jay S. Gunasekera, Sustainable Material Forming and Joining, 2019
Considerable research work has been performed in FSW and FSSW aiming at understanding the importance of various process conditions for sustainable and efficient manufacturing in terms of reduced defect formation and improved mechanical properties. In the case of FSSW of Al 6061 sheets, Su et al. (2006) demonstrated that the clamping mechanism and tool design contribute to energy utilization. It is observed that, while using a steel tool, the clamp and anvil support only 12.6% of the total energy generated during FSSW is transferred for welding the sheets. When using a mica clamp and anvil support, about 50% of the energy generated is transferred. The remaining energy generated during tool rotation dissipates in the tools, anvil, support plate, and environment. Moreover, about 4% of the total energy generated is contributed toward formation of the stir zone, while the remaining gets dissipated through the tools, anvil, clamp, and surrounding atmosphere. By improving the energy utilization and reducing the energy dissipation, the softer zone width and hence the distortion are reduced. It is also observed that for a tool geometry, the rotating pin has taken about 70% of the energy generated during spot welding.
Ultrasonic Welding (USW)
Published in Gary F. Benedict, Nontraditional Manufacturing Processes, 2017
The lateral-drive system is not only capable of performing spot welds, but with the proper welding tip, it can produce high-speed continuous lap seam welds. This is accomplished through the use of a rotating roller tip, as shown in Fig. 7.5. The edge of the roller is curved with a radius of 25.4–152.4 mm (1–6 in.). When welding wire, the roller will have a slot instead of a radius. Depending upon whether the tip or the workpiece is moving, the anvil will have different requirements. If the workpiece is moving and the roller tip is stationary, the anvil will also have to be constructed as a roller. As with spot welding, if the work-piece is rigid enough, the anvil is not required.
Optimization of process parameters of ultrasonic metal welding for multi layers foil of AL8011 material
Published in Welding International, 2023
Shah Samir, Komal Dave, Vishvesh Badheka, Dhaval Patel
Solid-state welding generated by ultrasonic metal welding requires high-frequency vibrations and moderate pressure and can be performed on similar or dissimilar metallic work parts. There are primarily four components that make up the ultrasonic welding system. The four components of the system are the transducer, electronic power supply, anvil and clamping mechanism as shown in Figure 1, By employing an ultrasonic transducer, the power supply supplies high-frequency electronic power. For this type of welding, a tool called a sonotrode generates high-frequency mechanical vibrations, which are sent to the workpiece via an auditory connection device. While welding, the anvil holds the workpiece steady and provides a tight clamping force. There are two primary kinds of ultrasonic welding systems. two-part wedge reed system, one-part lateral drives the latest research indicates that ultrasonic welding methods made use of a lateral driving mechanism. The anvil in lateral drive systems is ruggedly constructed to withstand bending and sustain the static clamping force employed to hold the workpiece [2].
Experimental investigation on ultrasonic spot welding of aluminum-cupronickel sheets under different parametric conditions
Published in Materials and Manufacturing Processes, 2019
Soumyajit Das, Mantra Prasad Satpathy, Ashutosh Pattanaik, Bharat Chandra Routara
As it was observed that the highest tensile shear strength was obtained at 68 µm vibration amplitude with 0.3 MPa of weld pressure thus, the correlation between various physical attributes and joint performance was established by the microstructural analysis and micro-hardness measurements on the weld cross-sectional area by varying various weld time values (0.4 s – 0.7 s). The FESEM pictures were taken at the weld cross-sections for different WTs of 0.4 s, 0.6 s, 0.7 s (Fig. 4). The dotted boxes in Fig. 4(a), (c) and (e) are presented in (b), (d) and (f) with higher magnification respectively. The gaps along the welded zone illustrated a lack of bonding between two sheets at low weld time of 0.4 s (Fig. 4(b)). The unbonded gaps were diminished with the rise in WT, and the intimate connections were made between the weld samples (Fig. 4(d), (f)). A noticeable observation during this study was that the indentations of horn and anvil increased with the increase in WT resulting in extreme energy input to the welding zone, and the materials were deformed.
Molecular dynamics simulation of atomic diffusion in friction stir spot welded Al to Cu joints
Published in Mechanics of Advanced Materials and Structures, 2022
Omkar Mypati, Polkampally Pavan Kumar, Perwej Iqbal, Surjya Kanta Pal, Prakash Srirangam
In continuation, a Lagrangian implicit method has been used to create a 3-D thermo-mechanical FSSW model for Cu-Al weld in lap configuration in DEFORM 3 D [20,21]. The base materials (BM), i.e., Cu and Al, are assumed as two different continuum rectangular bodies of dimensions 30 mm × 30 mm × 0.4 mm each, and are referred to as a rigid viscoplastic material, as shown in Figure 1a. A total of 53,470 elements of tetrahedral were utilized in meshing each plate. The both FSSW tool and the anvil plate are defined as rigid objects, and H13 is used as a tool material. The dimensions of the tool are 10 mm shoulder diameter, 0.4 mm tool pin length, and with a 5 mm tool pin diameter.