Laser impact welding for joining similar and dissimilar metal combinations with various target configurations

Significance 

More often than not, materials of dissimilar properties have to be joined in order to meet various technical obligations, financial considerations or environmental limitations. Specifically, recent advances in the automotive industry, aerospace, biomedical industries and microelectronics, call for joinery of dissimilar metals. Studies investigating the joining of dissimilar metals have revealed that brittle intermetallics are easily formed during welding of dissimilar metals in many alloy systems. Consequently, the formation of intermetallics in dissimilar metals joints usually result in poor mechanical performance and potential brittle fracture at the interface. To circumvent this shortfall, alternative approaches have been proposed. For instance, laser welding-brazing, explosive welding, magnetic pulse welding and laser impact welding (LIW). The first two have great potential; nonetheless, some underlying parameters yet to be resolved still impinge their large-scale adoption. On the other hand, LIW, developed for low temperature spot impact welding, utilizes the surface of a flyer plate to absorb the energy of the laser when the plasma is formed. A review of recent publications reveals that in such a setup, the velocity of this flyer is a critical parameter.

Generally, laser impact welding has been proved through the joining of aluminum and brass in recent studies. In these studies, however, the experimental setups were the same with flat target, in which the impact angle effect on the weld was not studied in order to increase the weld area along the collision interface. On this account, researchers from The Ohio State University: Dr. Huimin Wang, Dr. Dejian Liu, Professor John Lippold and Professor Glenn Daehn, conducted a series on experiments for joining of Ni-Ni, Al-Cu, Al-Ni and Al-Ti similar and dissimilar metal combinations with various experimental setups. Their goal was to assess the influence of LIW parameters. Their work is currently published in the Journal of Materials Processing Technology.

In their approach, used a 3-Joule pulsed laser to study the influence of LIW parameters on the launch of the flyer component as well as the bonding between the flyer and target. Metallurgical bonds between Ni-Ni, Al-Cu, Al-Ni and Al-Ti combinations were successfully produced. The bonding area was significantly increased (up to 30% of the impact region) when an appropriate impact angle was applied (nominally 7.5 degrees). In addition, Photon Doppler Velocimetry (PDV) was used to measure the impact velocity of the flyer during the LIW process.

The research team found that a wavy interface in all three dissimilar metal combinations. This helped prove that the yield stress of the target material has important influence on the morphology of the wavy interface. Further, a wavy interface with relatively long wave length and high amplitude was formed in Al-Cu LIW samples due to the low yield stress of Cu110 target plate.

In summary, the study demonstrated laser impact welding as an effective method for joining dissimilar metals. Interestingly, a characteristic wavy interface was observed in all LIW samples. In addition, the researchers demonstrated that the impact angle also plays a key role in the bonding process. In a statement to Advances in Engineering, the authors said that their work laid the foundation for future studies that will help advance the techniques of joining dissimilar metals.

Laser impact welding for joining similar and dissimilar metal combinations with various target configurations - Advances in Engineering

About the author

Huimin Wang is an Associate Professor in University of Science and Technology Beijing. She got her PhD degree from the Department of Materials Science and Engineering of The Ohio State University. She worked as Postdoc Researcher and Associate Researcher afterwards at The Ohio State University.

Her research interests are laser impact welding, welding metallurgy, material characterization. She has been working on laser impact welding since her PhD study and aims to reveal the bonding mechanism and improve the joining properties between dissimilar materials.

About the author

Dejian Liu, Associate Professor, is with the State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, P.R. China, He received his Ph.D degree from the Department of Materials Science and Engineering of Harbin Institute of Technology. He worked as Postdoc Researcher with the Welding Engineering Program, Department of Materials Science and Engineering, The Ohio State University, Columbus, OH.

His research interests are laser materials processing, laser-materials interactions, welding metallurgy, and material characterization.

About the author

John C. Lippold, Professor and College of Engineering Distinguished Faculty of Department of Materials Science and Engineering, The Ohio State University, Columbus, OH. He received his B.S., M.S. and Ph.D. degrees from Materials Engineering of Rensselaer Polytechnic Institute in 1973, 1975, and 1978, respectively. His research interests are fundamental concepts of welding metallurgy and welding ability, including weldability of advanced materials, weldability testing, weld defect formation and control, weld solidification behavior, phase transformations, physical/welding metallurgy of al-alloys, structural steels, stainless steels, nickel-base alloys, as well as materials joining education and training, distance education for welding engineering.

His professional activities include Fellow of ASM, Fellow of AWS, Chair of Editor board of Welding in the World, Editorial Board for Science and Technology of Welding and Joining, Chairman of Welding Journal Peer Review Committee, The Welding Institute (TWI) Research Board, ASM Handbook Committee, ASM Joining Council, AWS R&D Committee, AWS Awards Committee. Over 40 M.S. and 20 PhD students in the period from 1987 to present.

About the author

Glenn S. Daehn is the Mars G. Fontana Professor of Metallurgical Engineering at The Ohio State University. He received his Ph.D degree from Materials Science & Engineering, Stanford University. Glenn Daehn’s research, education and service efforts are all broadly related to the interwoven themes of Midwestern manufacturing revival, which in turn depends on technology development, integration of the University mission with regional industry and the development of a world-class workforce that is smart, creative and capable of making things. Glenn has been involved in a range of activities that encourage deep interaction between academia and industry.

He was the founder and is the current Director of the Ohio Manufacturing Institute. He is part of Ohio State’s leadership team for the Lightweight Innovations for Tomorrow Institute, founded by EWI, University of Michigan and Ohio State. He leads the Agile Manufacturing and Low Cost Tooling pillar.

Reference

Huimin Wang, Dejian Liu, John C. Lippold, Glenn S. Daehn. Laser impact welding for joining similar and dissimilar metal combinations with various target configurations. Journal of Materials Processing Technology, volume 278 (2020) 116498.

Go To Journal of Materials Processing Technology

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