scholarly journals Multi-Spot Ultrasonic Welding of Aluminum to Steel Sheets: Process and Fracture Analysis

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 779
Author(s):  
Michael Becker ◽  
Frank Balle
Keyword(s):  
Thermal Imaging ◽  
Dual Phase Steel ◽  
Limiting Factor ◽  
Filler Materials ◽  
Metal Structures ◽  
Ultrasonic Metal Welding ◽  
Steel Sheets ◽  
Metal Welding ◽  
Wrought Aluminum ◽  
First Time

Ultrasonic metal welding is an energy-efficient, fast and clean joining technology without the need of additional filler materials. Single spot ultrasonic metal welding of aluminum to steel sheets using automotive materials has already been investigated. Up to now, further studies to close the gap to application-relevant multi-metal structures with multiple weld spots generated are still missed. In this work, two different spot arrangements are presented, each consisting of two weld spots, joined 0.9 mm thick sheets of wrought aluminum alloy AA6005A-T4 with 1 mm sheets of galvannealed (galvanized and annealed) dual-phase steel HCT980X. An anvil equipped with variable additional clamping punches was used for the first time. The tensile shear forces reached 4076 ± 277 N for parallel connection and 3888 ± 308 N for series connection. Temperature measurements by thermocouples at the interface and through thermal imaging presented peak temperatures above 400 °C at the multi-metal interface. Microscopic investigations of fractured surfaces identified the Zn layer of the steel sheets as the strength-limiting factor. Energy-dispersive X-ray spectroscopy (EDX) indicated intermetallic phases of Fe and Zn in the border areas of the weld spots as well as the separation of the zinc layer from the steel within these areas.

scholarly journals 3D finite element model of dynamic material behaviors for multilayer ultrasonic metal welding

2021 ◽  
Vol 62 ◽  
pp. 302-312
Author(s):  
Ninggang Shen ◽  
Avik Samanta ◽  
Wayne W. Cai ◽  
Teresa Rinker ◽  
Blair Carlson ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
3D Finite Element ◽  
Ultrasonic Metal Welding ◽  
3D Finite Element Model ◽  
Material Behaviors ◽  
Metal Welding

scholarly journals Comparative investigation of lasing and amplification performance in cryogenic Yb:YLF systems

2021 ◽  
Vol 127 (3) ◽  
Author(s):  
Umit Demirbas ◽  
Martin Kellert ◽  
Jelto Thesinga ◽  
Yi Hua ◽  
Simon Reuter ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Estimation Method ◽  
Laser Cavity ◽  
Comparative Investigation ◽  
Limiting Factor ◽  
Experimental Conditions ◽  
Temperature Estimation ◽  
Transverse Temperature ◽  
First Time

AbstractWe present detailed experimental results with cryogenic Yb:YLF gain media in rod-geometry. We have comparatively investigated continuous-wave (cw) lasing and regenerative amplification performance under different experimental conditions. In the cw lasing experiments effect of crystal doping, cw laser cavity geometry and pump wavelength on lasing performance were explored. Regenerative amplification behavior was analyzed and the role of depolarization losses on performance was investigated. A recently developed temperature estimation method was also employed for the first time in estimating average crystal temperature under lasing conditions. It is shown that the thermal lens induced by transverse temperature gradients is the main limiting factor and strategies for future improvements are discussed. To the best of our knowledge, the achieved results in this study (375 W in cw, and 90 W in regenerative amplification) are the highest average powers ever obtained from this system via employing the broadband E//a axis.

scholarly journals Effects of α+γ Intercritical and γ Single-Phase Annealing on Martensitic Texture Evolution in Dual-Phase Steel Sheets

2018 ◽  
Vol 58 (6) ◽  
pp. 1136-1145
Author(s):  
Hidekazu Minami ◽  
Kaneharu Okuda ◽  
Shinjiro Kaneko ◽  
Yasunobu Nagataki
Keyword(s):  
Dual Phase Steel ◽  
Single Phase ◽  
Texture Evolution ◽  
Dual Phase ◽  
Steel Sheets

Process Monitoring in Ultrasonic Metal Welding of Lithium Batteries by Power Signals

2021 ◽  
pp. 1-22
Author(s):  
Xinhua Shi ◽  
Lin Li ◽  
Suiran Yu ◽  
Lingxiang Yun
Keyword(s):  
Electric Power ◽  
Process Monitoring ◽  
Lithium Batteries ◽  
Welding Process ◽  
Ultrasonic Metal Welding ◽  
Isometric Transformation ◽  
Welding Defects ◽  
Different Types ◽  
Metal Welding ◽  
Welding Processes

Abstract Ultrasonic metal welding is one of the key technologies in manufacturing lithium batteries, and the welding quality directly determines the battery performance. Therefore, an online welding process monitoring system is critical in identifying abnormal welding processes, detecting defects, and improving battery quality. Traditionally, the peak welding power is used to indicate abnormal process signals in welding process monitoring systems. However, since various factors have complex impacts on the electric power signals of ultrasonic welding processes, the peak power is inadequate to detect different types of welding defects. Therefore, a signal pattern matching method is proposed in this study, which is based on the electric power signal during the entire welding process and thus is capable of identifying abnormal welding processes in various conditions. The proposed method adopts isometric transformation and homogenization as signal pretreatment methods, and Euclidean distance is used to calculate the similarity metric for signal matching. The effectiveness and robustness of the proposed method are experimentally validated under different abnormal welding conditions.

Tool Wear Monitoring for Ultrasonic Metal Welding of Lithium-Ion Batteries

2015 ◽  
Author(s):  
Chenhui Shao ◽  
Tae Hyung Kim ◽  
S. Jack Hu ◽  
Jionghua (Judy) Jin ◽  
Jeffrey A. Abell ◽  
...  
Keyword(s):  
Tool Wear ◽  
Lithium Ion ◽  
Production Costs ◽  
Tool Wear Monitoring ◽  
Surface Geometry ◽  
Ultrasonic Metal Welding ◽  
Tool Condition ◽  
Wear Monitoring ◽  
Tool Replacement ◽  
Metal Welding

This paper presents a tool wear monitoring framework for ultrasonic metal welding which has been used for lithium-ion battery manufacturing. Tool wear has a significant impact on joining quality. In addition, tool replacement, including horns and anvils, constitutes an important part of production costs. Therefore, a tool condition monitoring (TCM) system is highly desirable for ultrasonic metal welding. However, it is very challenging to develop a TCM system due to the complexity of tool surface geometry and a lack of thorough understanding on the wear mechanism. Here, we first characterize tool wear progression by comparing surface measurements obtained at different stages of tool wear, and then develop a tool condition classification algorithm to identify the state of wear. The developed algorithm is validated using tool measurement data from a battery plant.

scholarly journals Is Young Age a Limiting Factor When Training Balance? Effects of Child-Oriented Balance Training in Children and Adolescents

2018 ◽  
Vol 30 (1) ◽  
pp. 176-184 ◽  
Author(s):  
Michael Wälchli ◽  
Jan Ruffieux, ◽  
Audrey Mouthon ◽  
Martin Keller ◽  
Wolfgang Taube
Keyword(s):  
Postural Control ◽  
Postural Sway ◽  
Age Groups ◽  
Balance Training ◽  
Young Age ◽  
Limiting Factor ◽  
Training Outcomes ◽  
Balance Exercises ◽  
Explosive Force ◽  
First Time

Purpose: Balance training (BT) studies in children reported conflicting results without evidence for improvements in children under the age of 8. The aim of this study therefore was to compare BT adaptations in children of different age groups to clarify whether young age prevents positive training outcomes. Methods: The effects of 5 weeks of child-oriented BT were tested in 77 (38 girls and 39 boys) participants of different age groups (6–7 y, 11–12 y, and 14–15 y) and compared with age-matched controls. Static and dynamic postural control, explosive strength, and jump height were assessed. Results: Across age groups, dynamic postural sway decreased (−18.7%; P = .012; ) and explosive force increased (8.6%; P = .040; ) in the intervention groups. Age-specific improvements were observed in dynamic postural sway, with greatest effects in the youngest group (−28.8%; P = .026; r = .61). Conclusion: In contrast to previous research using adult-oriented balance exercises, this study demonstrated for the first time that postural control can be trained from as early as the age of 6 years in children when using child-oriented BT. Therefore, the conception of the training seems to be essential in improving balance skills in young children.

Ultrasonic Rapid Manufacturing: Implementation and Thermo-Mechanical Analysis

2002 ◽  
Author(s):  
Shailendra Yadav ◽  
Charalabos Doumanidis
Keyword(s):  
Temperature Effects ◽  
Welding Process ◽  
Mechanical Analysis ◽  
Ultrasonic Welding ◽  
Solid Metal ◽  
Rapid Manufacturing ◽  
Mechanical Process ◽  
Ultrasonic Metal Welding ◽  
Metal Parts ◽  
Metal Welding

This paper addresses a novel non-thermal Ultrasonic Rapid Manufacturing (URM), for layered parts based on Ultrasonic Metal Welding (USW). Its laboratory implementation, automation and integration are described first. The thermo-mechanical process aspects (i.e. heat generation and resulting temperature effects) during each cycle of ultrasonic welding are then studied. The technical advantages of ultrasonic welding process, including fabrication of dense, full-strength functional solid metal parts, multi-material composites, and active parts with embedded intelligent components and electronic, mechatronic, optic and fluidic structures, are examined.

scholarly journals Heating of Ti3C2Tx MXene/polymer composites in response to Radio Frequency fields

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Touseef Habib ◽  
Nutan Patil ◽  
Xiaofei Zhao ◽  
Evan Prehn ◽  
Muhammad Anas ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Thermal Imaging ◽  
Electromagnetic Waves ◽  
Rapid Heating ◽  
Composite Films ◽  
Heating Rates ◽  
New Material ◽  
High Dielectric ◽  
First Time ◽  
Percolating Network

Abstract Here we report for the first time that Ti3C2Tx/polymer composite films rapidly heat when exposed to low-power radio frequency fields. Ti3C2Tx MXenes possess a high dielectric loss tangent, which is correlated with this rapid heating under electromagnetic fields. Thermal imaging confirms that these structures are capable of extraordinary heating rates (as high as 303 K/s) that are frequency- and concentration-dependent. At high loading (and high conductivity), Ti3C2Tx MXene composites do not heat under RF fields due to reflection of electromagnetic waves, whereas composites with low conductivity do not heat due to the lack of an electrical percolating network. Composites with an intermediate loading and a conductivity between 10–1000 S m−1 rapidly generate heat under RF fields. This finding unlocks a new property of Ti3C2Tx MXenes and a new material for potential RF-based applications.

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