Article
Materials Science, Multidisciplinary
Ali Rasouli, Homam Naffakh-Moosavy
Summary: NiTi shape memory alloy (SMA) offers various industrial applications, but the formation of intermetallic compounds in the joint with Ni20Cr alloy leads to reduced mechanical properties and increased hardness. Post-weld heat treatment can alter the microstructure and mechanical properties of the welded joint and produce NiTi intermetallic phase.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Automation & Control Systems
Kian Zarghami, Saeed Khademzadeh, Nader Parvin, Yashar Azarmehr
Summary: The research utilized Ni50.8Ti49.2 pre-alloyed powder and mu DMD process to produce NiTi shape memory alloy coatings on stainless steel 316L substrate. The study found that scanning velocity and laser power significantly affected coating quality, with cracks forming at lower scanning speeds.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2021)
Article
Engineering, Industrial
Behzad Farhang, Ahmet Alptug Tanrikulu, Aditya Ganesh-Ram, Ankur Jain, Amirhesam Amerinatanzi
Summary: In recent years, laser welding has been considered as a promising technology for joining smart alloys (e.g., NiTi) to structural materials (e.g., SS) due to its advantages such as precise heat control and narrow fusion zone. However, the formation of brittle intermetallic components (IMCs) during the welding process remains a challenge. This study investigates a novel technique using an external magnetic field to suppress the formation of IMCs and improve the strength and ductility of the joints.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2023)
Article
Automation & Control Systems
Yi Chen, Mingpeng Cheng, Chao Liu, Yang Li, Zhen Luo, Sansan Ao
Summary: Ultrasonic spot welding (USW) is an emerging solid-state joining technology that shows great potential for bonding Ni-Ti shape memory alloys and stainless steel (SS). This study successfully welded Ni-Ti shape memory alloy and 304 SS using USW, with copper and aluminum interlayers to enhance joint strength. The results demonstrate effective bonding between Ni-Ti and 304 SS, with the highest bond strengths achieved using an aluminum interlayer, although some brittle intermetallic compounds were generated. A slightly lower joint strength was obtained using a copper interlayer, but no brittle intermetallic compounds were formed. These findings have important implications for bonding NiTi with dissimilar materials.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Fuguo Ge, Bei Peng, Joao Pedro Oliveira, Wenchao Ke, Fissha Biruke Teshome, Yongmei Li, Zhi Zeng
Summary: NiTi-based shape memory alloys and the Ti2AlNb alloy are becoming increasingly important in the aerospace field. By using a Niobium (Nb) interlayer via laser welding, dissimilar joints between a NiTi shape memory alloy and Ti2AlNb alloy were obtained. Through process optimization, sound joints with a mechanical strength of over 1230 N were achieved, making them suitable for structural applications.
Article
Materials Science, Multidisciplinary
Hongwei Wang, Jilin Xie, Yuhua Chen, Wenkuo Liu, Wenbin Zhong
Summary: This study investigates the effect of adding a high entropy alloy interlayer on the microstructure and properties of NiTi SMA/304 SS laser-welded joint. The results show that the addition of the high entropy alloy interlayer significantly reduces the formation of brittle intermetallic compounds, improves the tensile shear properties of the joint, and decreases the microhardness of the weld metal.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Materials Science, Multidisciplinary
J. P. Oliveira, Jiajia Shen, J. D. Escobar, C. A. F. Salvador, N. Schell, N. Zhou, O. Benafan
Summary: Laser welding of a Ni-rich NiTi-20Zr high temperature shape memory alloy was successfully conducted, resulting in defect-free welds. The microstructure of the joints was altered by the weld thermal cycle, affecting hardness and mechanical properties. This study demonstrates the potential of advanced laser joining methods in these alloys.
MATERIALS & DESIGN
(2021)
Article
Chemistry, Physical
Tomasz Goryczka, Karol Gryn, Adrian Barylski, Barbara Szaraniec
Summary: Joining NiTi wires with shape memory effect and pseudoelasticity is challenging due to unwanted phase interactions, but a basic laser welding technique can be used to overcome this issue. By optimizing the laser power, high-quality welds with good reversible martensitic transformation and pseudoelasticity can be obtained.
Article
Materials Science, Multidisciplinary
Matthieu B. Lezaack, Aude Simar, Yannick Marchal, Martin Steinmetz, Koen Faes, Joao Pacheco de Almeida
Summary: Integration of NiTi superelastic bars with steel reinforcing bars is a promising method to enhance the seismic performance of reinforced concrete structures. Friction welding is investigated as a possible technique for joining NiTi alloy and steel, with attention paid to keeping the intermetallic layer thin and limiting cracks in the steel layer next to the interface.
SCIENCE AND TECHNOLOGY OF WELDING AND JOINING
(2022)
Article
Nanoscience & Nanotechnology
Kaiping Zhang, Peng Peng, Y. Norman Zhou
Summary: High strength NiTi-SS wire joints were achieved using laser welding-brazing mode, which improved the tensile strength and suppressed the overall brittleness of the joints.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Sneha Samal, Mikulas Sulovsky, Jaromir Kopecek, Petr Sittner
Summary: The surface behavior of NiTi coating was studied through composition analysis, microstructure, and interface diffusion. The shape memory effect was investigated by thermal recovery of the indented surface at different loads. Samples from graphite substrate showed high Vickers hardness near theoretical density and varied with different loads, while samples from stainless steel substrate displayed more homogeneous hardness at various loads. Both samples exhibited a hysteresis effect of shape memory effect on bending mode in thermal cycles. Recovery in the depth of indent points was analyzed after heating samples above austenite finish temperature, with a maximum recovery of 77%.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Automation & Control Systems
Qi Cheng, Ning Guo, Yunlong Fu, Di Zhang, Shuai Zhang, Xin Zhang, Hao Chen, Lei Wang, Jinlong He
Summary: By studying the stiffness of the laminated structure and the driving ability of NiTi shape memory alloy, the optimal layout of the 2A12 aluminum alloy/NiTi shape memory alloy laminated structure was obtained. This research provides important design basis and technical reserve for the application of intelligent stiffness control technology in a hypersonic environment.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Chemistry, Physical
Lei Kang, Xin Li, Jing Chen, Yu Zhang, Ting Wang
Summary: This research investigated the microstructures and mechanical properties of laser penetration welded joints of overlap steel-on-aluminum. It was found that adding a nickel interlayer significantly enhanced the tensile property of the joint and decreased the hardness of the intermetallic compounds, thus improving the toughness of the welded joint.
Article
Materials Science, Multidisciplinary
Nana Kwabena Adomako, Giseung Shin, Nokeun Park, Kyoungtae Park, Jeoung Han Kim
Summary: High entropy alloys (HEAs) exhibit superior mechanical properties and have been used in structural materials in nuclear and aerospace applications. A dissimilar joint between CoCrFeMnNi-HEA and duplex stainless steel (DSS) was created through laser beam welding, resulting in a sound joint with FCC phase in the weld metal. Postweld heat treatment (PWHT) showed a decrease in hardness for the weld metal, HEA, and DSS, with HEA experiencing a more significant reduction. Additionally, a strength of 584 MPa with low ductility was achieved after welding, and applying PWHT resulted in increased ductility with only a marginal reduction in strength. Future studies will focus on using laser beam offset welding to improve the mechanical properties of dissimilar joints.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
H. Z. Lu, L. H. Liu, X. Luo, H. W. Ma, W. S. Cai, R. Lupoi, S. Yin, C. Yang
Summary: In this study, the formation mechanisms and influences of heterogeneous nonequilibrium microstructures in NiTi fabricated by laser powder bed fusion (LPBF) additive manufacturing were investigated. The results showed that the heterogeneous microstructures were due to high undercooling, cooling rate, and residual thermal stress during LPBF solidification, as well as the enrichment of Ti atoms at the solidification front. Interestingly, a two-way shape memory strain of 0.8% was achieved in LPBF NiTi through cyclic loading-unloading-heating-cooling training process.
MATERIALS & DESIGN
(2023)
Article
Automation & Control Systems
Miguel Araujo Machado, Luis Filipe Soldado Granadeiro Rosado, Nuno Alberto Marques Mendes, Rosa Maria Mendes Miranda, Telmo Jorge Gomes dos Santos
Summary: An innovative system for detecting surface and sub-surface welding defects in laser-brazed joints is presented, operating autonomously and integrated with a robotized arm. Customized eddy current probes were designed and experimentally validated for detecting pore defects with 0.13 mm diameter and sub-surface defects buried 1 mm deep. The integration of the system with the manufacturing process towards an Industry 4.0 quality control paradigm is also discussed.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Valeriy Gornyakov, Jialuo Ding, Yongle Sun, Stewart Williams
Summary: Post-build rolling can effectively mitigate residual stress and distortion in WAAM-built components, with slotted rollers being the most effective in introducing tensile plastic strain to counteract compressive strain generated during WAAM deposition. The rolling load and roller-to-wall friction coefficient significantly influence the effectiveness of the mitigation process, providing insights for the development of optimal post-build rolling processes in WAAM manufacturing.
MATERIALS & DESIGN
(2022)
Article
Automation & Control Systems
Julio Coroado, Stewart Williams, Wojciech Suder, Supriyo Ganguly, Sonia Meco, Goncalo Pardal
Summary: The research finds that frequency is an important parameter affecting heat loss in laser welding. Under low-frequency conditions, the pulsed wave (PW) laser has lower melting efficiency and higher penetration efficiency. On the other hand, under high-frequency conditions, the PW laser has lower melting and penetration efficiency compared to the continuous wave (CW) laser. In addition, a new definition of interaction time is proposed, which allows for a comparison between CW and PW lasers and can be used to predict penetration depth.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Automation & Control Systems
German O. Barrionuevo, Pedro M. Sequeira-Almeida, Sergio Rios, Jorge A. Ramos-Grez, Stewart W. Williams
Summary: Wire arc additive manufacturing (WAAM) is a promising technology for processing various welding materials, with high production rate and capability to handle large geometries, particularly in the aeronautical industry. This study evaluates the melting efficiency using machine learning algorithms and compares the results with a simplified analytical model.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Engineering, Industrial
Guangyu Chen, Stewart Williams, Jialuo Ding, Chong Wang, Wojciech Suder
Summary: The study on the use of the multi-energy source method for wire-based directed energy deposition demonstrated independent control of layer width and height. By adjusting wire feed speed and laser scanning width, the shape and size of the bead were successfully controlled. Experimental results showed the significance of the multi-energy source method for wire-based directed energy deposition.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2022)
Article
Engineering, Manufacturing
Guangyu Chen, Stewart Williams, Jialuo Ding, Yipeng Wang, Wojciech Suder
Summary: A split anode calorimeter (SAC) was developed to measure the energy density of plasma transferred arc (PTA). The SAC was calibrated using a laser beam with a well-defined energy profile. The results confirmed the accuracy of the SAC method and its suitability for measuring the energy distribution of an electric arc. It was observed that the PTA energy profile was distorted when crossing over the split anode interface of the SAC, but this was corrected by adjusting the position of the ground wire. Analysis of the energy density profiles generated from current density and temperature distribution showed that the effective energy distribution is wider than the width of the arc column due to other energy transfer processes.
JOURNAL OF MANUFACTURING PROCESSES
(2022)
Article
Computer Science, Artificial Intelligence
Jian Qin, Yipeng Wang, Jialuo Ding, Stewart Williams
Summary: This study proposed a deep learning-based technology for controlling the droplet transfer mode in WAAM process, achieving high accuracy in identifying transfer mode through data collection and neural network model, thereby improving process stability and deposition quality.
JOURNAL OF INTELLIGENT MANUFACTURING
(2022)
Article
Materials Science, Multidisciplinary
Rastislav Zimermann, Ehsan Mohseni, Randika K. W. Vithanage, David Lines, Euan Foster, Charles N. Macleod, Stephen Gareth Pierce, Gianrocco Marinelli, Stewart Williams, Jialuo Ding
Summary: This study introduces the concept of Virtual Source Aperture (VSA) for ultrasonic roller-probe inspection and demonstrates that VSA requires a significantly lower number of transmissions compared to Full Matrix Capture (FMC). It also increases the energy levels and reduces the data size by almost 50%, resulting in a doubling of the inspection speed.
MATERIALS & DESIGN
(2022)
Article
Chemistry, Analytical
Rastislav Zimermann, Ehsan Mohseni, Momchil Vasilev, Charalampos Loukas, Randika K. W. Vithanage, Charles N. Macleod, David Lines, Yashar Javadi, Misael Pimentel Espirindio E Silva, Stephen Fitzpatrick, Steven Halavage, Scott Mckegney, Stephen Gareth Pierce, Stewart Williams, Jialuo Ding
Summary: The demand for cost-efficient manufacturing of complex metal components has driven research for metal Additive Manufacturing (AM) such as Wire + Arc Additive Manufacturing (WAAM). A synchronized multi-robot WAAM and NDE cell is developed to detect defects in the manufacturing process, enable in-process repair, and prevent costly scrappage or rework of defective builds.
Article
Engineering, Manufacturing
Yao Lu, Jun Wang, Stewart Williams, Lisong Zhu, Jialuo Ding, Chenglei Diao, Zhengyi Jiang
Summary: A functionally graded AlxCoCrFeNi high entropy alloy with a variation in Al concentration along the building direction was successfully produced using a hybrid powder-bed wire-based direct energy deposition process. The alloy exhibited a continuous transition from a single FCC structure to a major BCC+minor FCC dual-phase structure, which was facilitated by the remelting and reheating process during the deposition. The mechanical properties of the alloy showed higher strength and hardening rate but lower plasticity in areas with higher Al content.
ADDITIVE MANUFACTURING
(2023)
Article
Engineering, Civil
E. Ghafoori, H. Dahaghin, C. Diao, N. Pichler, L. Li, M. Mohri, J. Ding, S. Ganguly, S. Williams
Summary: In this study, the fatigue strengthening of damaged steel members was conducted using a directed energy deposition (DED) process called wire arc additive manufacturing (WAAM). Experimental and finite element (FE) simulation results showed that the WAAM process introduced compressive residual stresses at the crack tip and stress concentration at the root of the as-deposited WAAM, which can be mitigated by machining. Fractography analysis revealed that cracks were initiated at the WAAM-steel interface and microscopic observations showed that the microcracks were arrested by the porosities in the melted interface. Overall, this pioneering study highlights the promising potential of WAAM repair for combating fatigue damage in steel structures.
ENGINEERING STRUCTURES
(2023)
Article
Chemistry, Analytical
Charalampos Loukas, Momchil Vasilev, Rastislav Zimmerman, Randika K. W. Vithanage, Ehsan Mohseni, Charles N. MacLeod, David Lines, Stephen Gareth Pierce, Stewart Williams, Jialuo Ding, Kenneth Burnham, Jim Sibson, Tom O'Hare, Michael R. Grosser
Summary: The increasing demand for cost-efficient manufacturing and metrology inspection solutions in high-value manufacturing sectors has led to the integration of automated robotic solutions. However, the current manipulators using traditional programming approaches are inflexible and challenging to adapt to unique specifications per component. This study proposes a novel software system that utilizes an off-the-shelf force-torque sensor to achieve real-time kinesthetic guidance for path planning, resulting in improved performance and programming time.
Article
Chemistry, Analytical
Jian Qin, Javier Vives, Parthiban Raja, Shakirudeen Lasisi, Chong Wang, Thomas Charrett, Jialuo Ding, Stewart Williams, Jonathan Mark Hallam, Ralph Tatam
Summary: Part quality monitoring and control in wire-based directed energy deposition additive manufacturing (w-DEDAM) processes has been a topic of continuous interest. This paper investigates the behavior of interlayer deposition height in different wall regions, particularly the transition areas, when process parameters change. It also explores the potential of using geometry monitoring information for interlayer wall height compensation during w-DEDAM part-building.
Article
Engineering, Industrial
Guangyu Chen, Jialuo Ding, Yongle Sun, Xin Chen, Chong Wang, Goncalo Rodrigues Pardal, Stewart Williams
Summary: This study proposes an innovative method to accelerate the thermal analysis of the scanning laser (SL) process for additive manufacturing (AM) by reducing the order of the finite element model. The method achieves high accuracy while significantly reducing computational time and element amount. Additionally, the introduction of an equivalent heat source improves computational efficiency. This method can be applied to parametric analysis and optimization of novel AM processes, as well as thermal analyses of large structures AM and other manufacturing processes.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2023)
