TY - JOUR
T1 - Effect of Laser Surfacing on the Microstructure and Mechanical Properties of Ultrasonic Welded NiTi Joints
AU - Ao, Sansan
AU - Li, Chunjie
AU - Zhang, Wei
AU - Oliveira, João Pedro
AU - Zeng, Zhi
AU - Luo, Zhen
N1 - Funding Information:
Supporting for the Chinese Civil Aviation Administration (No. U1933129), the Chinese National Key Program (No. 2018YFB1107900), Natural Science Foundation of Tianjin City (Nos. 18JCQNJC04100, 19JCZDJC39000, and 19YFFCYS00090), Natural Science Foundation of China (No. 51775091) is acknowledged. JPO acknowledges the Fundação para a Ciência e Tecnologia (FCT) for its support via the project UID/00667/2020 (UNIDEMI).
Publisher Copyright:
© 2021 Copernicus GmbH. All rights reserved.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2022/1/1
Y1 - 2022/1/1
N2 - In the present work, the effects of laser surfacing aiming at modifying the surface roughness on NiTi sheets prior to the application of ultrasonic welding (USW) were investigated. Three different configurations joining original and laser surfaced specimens were performed: original/original (referred as O/O), original/treated (referred as O/T), and treated/treated (referred as T/T). The influence of surface roughness on the interface formation, diffusion, and mechanical properties was investigated. It is observed that when both bonding surfaces becomes rougher (T/T configuration), the joint strength is the highest, followed by both smooth bonding surfaces (O/O configuration), and the strength of the joint is the lowest when only one of the bonding surfaces was roughened (O/T configuration), which is related to the degree of plastic deformation at the joining interface. The main joining mechanism of NiTi to the Al interlayer was a metallic bonding caused by shear plastic deformation and formation and growth of micro welds at the joining interfaces. Laser surfacing facilitates the metallic bonding, which is directly reflected in the change of the thickness of the Al interlayer after USW. This also helps to produce a mechanical interlocking at the interface, although there is no significant difference in the elemental diffusion. Interfacial failure occurred in all joints tested under different surface contact conditions and exhibited ductile-like fracture characteristics.
AB - In the present work, the effects of laser surfacing aiming at modifying the surface roughness on NiTi sheets prior to the application of ultrasonic welding (USW) were investigated. Three different configurations joining original and laser surfaced specimens were performed: original/original (referred as O/O), original/treated (referred as O/T), and treated/treated (referred as T/T). The influence of surface roughness on the interface formation, diffusion, and mechanical properties was investigated. It is observed that when both bonding surfaces becomes rougher (T/T configuration), the joint strength is the highest, followed by both smooth bonding surfaces (O/O configuration), and the strength of the joint is the lowest when only one of the bonding surfaces was roughened (O/T configuration), which is related to the degree of plastic deformation at the joining interface. The main joining mechanism of NiTi to the Al interlayer was a metallic bonding caused by shear plastic deformation and formation and growth of micro welds at the joining interfaces. Laser surfacing facilitates the metallic bonding, which is directly reflected in the change of the thickness of the Al interlayer after USW. This also helps to produce a mechanical interlocking at the interface, although there is no significant difference in the elemental diffusion. Interfacial failure occurred in all joints tested under different surface contact conditions and exhibited ductile-like fracture characteristics.
KW - interface formation
KW - joining mechanisms
KW - laser surfacing
KW - NiTi shape memory alloys
KW - surface roughness
KW - ultrasonic spot welding
KW - welding and joining
UR - http://www.scopus.com/inward/record.url?scp=85109192534&partnerID=8YFLogxK
U2 - 10.1115/1.4051330
DO - 10.1115/1.4051330
M3 - Article
AN - SCOPUS:85109192534
SN - 1087-1357
VL - 144
JO - Journal of Manufacturing Science and Engineering, Transactions of the ASME
JF - Journal of Manufacturing Science and Engineering, Transactions of the ASME
IS - 1
M1 - 011003
ER -