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
Engineering, Manufacturing
A. Shamsolhodaei, A. GhateiKalashami, A. Safdel, A. R. H. Midawi, M. A. Elbestawi, P. Peng, Y. N. Zhou
Summary: Resistance spot welding is capable of providing a sound joint between superelastic NiTi shape memory alloy sheets. The welded sample showed a fully austenitic structure without any visible defects. The fusion zone had a homogenous microhardness distribution, although it was slightly lower than the base material due to the larger grain size in the weld nugget. The superelastic response of the NiTi alloy was preserved after the welding process, which is significant.
JOURNAL OF MANUFACTURING PROCESSES
(2022)
Article
Materials Science, Multidisciplinary
Fissha Biruke Teshome, Bei Peng, J. P. Oliveira, Jiajia Shen, Sansan Ao, Haoyue Li, Long Chen, Caiwang Tan, Xiaoguo Song, Naixun Zhou, Zhi Zeng
Summary: Obtaining a reliable NiTi to Ti6Al4V dissimilar joint with NiTi's superelasticity can provide design flexibility in aerospace and biomedical fields. Adding Pd can limit the formation of Ti2Ni intermetallic compounds, resulting in improved mechanical properties and superelastic behavior of the NiTi-Ti6Al4V joint. The presence of Pd also leads to a decrease in the fraction of Ti2Ni and the dominance of Ti-Pd and NiTi compounds in the fusion zone.
MATERIALS & DESIGN
(2023)
Article
Engineering, Manufacturing
S. S. Ao, W. Zhang, C. J. Li, J. P. Oliveira, Z. Zeng, Z. Luo
Summary: By adjusting the welding vibration amplitude and optimizing the process parameters, ultrasonic spot welding of NiTi thin sheets with a Cu interlayer can achieve excellent bonding interface and recrystallized microstructure near the bonding interface, leading to improved mechanical performance of the joints compared to the NiTi base material.
MATERIALS AND MANUFACTURING PROCESSES
(2021)
Article
Chemistry, Physical
Bingyao Yan, Yanqiu Zhang, Shuyong Jiang, Junbo Yu, Dong Sun, Ming Tang
Summary: The mechanical properties and fracture mechanisms of martensitic NiTi shape memory alloy were studied through thermomechanical processing, leading to significant changes in microstructure and differences in plasticity and fracture strength of the alloy. The decrease in plasticity in the annealed alloy is mainly attributed to the reduction of reorientation+detwinning zone and plastic zone, as well as the difference in crack-path configuration resulting in a larger proportion of fracture mode I in the annealed alloy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Automation & Control Systems
Luiz Fernando Alves Rodrigues, Fernando Andrade Amorim, Estephanie Nobre Dantas Grassi, Pedro Luiz Lima dos Santos, Carlos Jose de Araujo
Summary: This study aims to investigate the spot welding of NiTi SMA wires using the TIG process and determine the parameters for achieving full penetration. The weld penetration was evaluated using optical microscopy and an optimization tool called CRCD, which identified three optimal parameters. The experimental results demonstrate the potential of TIG spot welding in fabricating complex structures of NiTi SMA.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Engineering, Biomedical
Elisa Kassab, Jose Antonio da Cunha Ponciano Gomes
Summary: This study evaluated the corrosion effects on fracture of nickel-titanium superelastic wires in physiological solutions, showing localized corrosion in fluoride-containing solutions but no corrosion in NaCl solutions. The corrosion resistance of strained and unstrained wires did not differ significantly, yet brittle-like fracture was observed in solutions with both NaCl and NaF. The use of superelastically strained NiTi in oral environments with fluoride poses a significant risk of corrosion-induced fracture.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
A. Sibirev, S. Belyaev, N. Resnina
Summary: The study investigates the influence of counter-body stiffness on the recovery stress, recoverable strain, and work output during thermal cycling of NiTi cylindrical samples in the actuator regime. Results show a nonlinear relationship between stiffness values and shape memory effect/recovery stress, and a gradual decrease in recovery stress, work output values during thermal cycling.
SENSORS AND ACTUATORS A-PHYSICAL
(2021)
Article
Engineering, Manufacturing
Yuxin Wang, Sansan Ao, Wei Zhang, Anqi Wang, Mingpeng Cheng, Yi Chen, J. P. Oliveira, Z. Zeng, Zhen Luo
Summary: This study developed a three-dimensional finite element analysis model for ultrasonic spot welding of superelastic NiTi shape memory alloy with Cu interlayer. The temperature and stress distributions during the welding process were simulated and analyzed. The results showed that the highest temperature occurred in the center of the welding area and the maximum stress occurred at the center of the contact surface between upper NiTi and Cu interlayer.
JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING-TRANSACTIONS OF THE ASME
(2022)
Article
Materials Science, Multidisciplinary
A. Shamsolhodaei, M. H. Razmpoosh, C. Maletta, P. Magaro, Y. N. Zhou
Summary: The study investigated the superelastic response of laser welded NiTi wires through nanoindentations and cyclic tensile tests. High power laser conditions led to deterioration in superelasticity, while reducing laser power improved superelasticity. Furthermore, increasing the cyclic tensile test temperature helped to eliminate unfavorable martensite phases and achieve similar superelastic responses.
Article
Materials Science, Multidisciplinary
Toni Sprigode, Andreas Gester, Guntram Wagner, Thomas Mader, Bjorn Senf, Welf-Guntram Drossel
Summary: In this study, NiTiCu shape memory alloy wires were joined with silver-coated copper ferrules via ultrasonic spot welding, with tensile tests showing that the ultimate tensile strengths of the joints reached almost 100% of the base material. The ultrasonic welding process did not affect the transition temperatures of the shape memory alloy.
Review
Materials Science, Multidisciplinary
Fuzhen Sun, Xinxin Feng, Haizhen Wang, Xinjian Cao, Xiao Liu, Yang Liu, Yan Li, Zhongli Liu, Xiaoyang Yi
Summary: Shape memory alloys are smart materials that have superior properties and are widely used in aerospace, naval, automobile, and biomedicine industries. Functionally graded shape memory alloys are created to achieve accurate controllability for progressive movement. This review paper discusses the classification, fabrications, microstructural features, and performances of functionally graded shape memory alloys. Creating various gradients in shape memory alloys can widen the transformation temperature intervals and transformation stress intervals, leading to excellent performances and wider application range.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Junyu Chen, Liping Lei, Gang Fang, Dongwei Wang
Summary: This study investigates the grain size dependence of the elastocaloric effect of NiTi and finds a suitable grain size that yields good cooling properties. The grain size has different effects on various refrigeration metrics, such as adiabatic temperature variation, isothermal entropy change, energy dissipation, cyclic stability, and working temperature span. The 30 nm grain size specimen demonstrates excellent comprehensive performance and repeatability, making it a promising elastocaloric refrigerant candidate.
MATERIALS TODAY NANO
(2023)
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
Engineering, Manufacturing
S. S. Ao, C. J. Li, W. Zhang, J. P. Oliveira, Z. Zeng, Z. Luo
Summary: The effects of laser surfacing on surface roughness of NiTi sheets prior to ultrasonic welding were investigated. It was found that surface roughness significantly influenced interface formation, diffusion, and mechanical properties.
JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING-TRANSACTIONS OF THE ASME
(2022)
Article
Materials Science, Multidisciplinary
G. G. Ribamar, J. D. Escobar, A. Kwiatkowski da Silva, N. Schell, J. A. Avila, A. S. Nishikawa, J. P. Oliveira, H. Goldenstein
Summary: The addition of Si to steels delays cementite precipitation and promotes carbon partitioning from martensite to retained austenite, which improves ductility and toughness. The present study investigates the carbon partitioning and austenite decomposition in a modified Si hypereutectoid bearing steel during tempering. The results show that carbon partitioning occurs at temperatures below 300 degrees C without significant phase decomposition, and a transition temperature for austenite carbon enrichment and decomposition is observed at 350 degrees C.
Article
Nanoscience & Nanotechnology
Jiajia Shen, Rita Goncalves, Yeon Taek Choi, J. G. Lopes, Jin Yang, N. Schell, Hyoung Seop Kim, J. P. Oliveira
Summary: This study establishes a correlation between welding process, microstructure, and mechanical properties, laying the foundations for the successful joining and application of welded joints based on high entropy alloys using low-cost arc-based welding technologies.
SCRIPTA MATERIALIA
(2023)
Article
Nanoscience & Nanotechnology
Wei Zhang, Jiajia Shen, J. P. Oliveira, Bart J. Kooi, Yutao Pei
Summary: In this study, laser powder bed fusion was used to fabricate an interstitial-strengthened high entropy alloy. Microstructural characteristics were evaluated using electron backscatter diffraction and high energy synchrotron X-ray diffraction. Tensile testing and micro-pillar compression tests were performed to reveal the deformation mechanisms and the influence of grain orientation.
SCRIPTA MATERIALIA
(2023)
Article
Thermodynamics
Wenchao Ke, Zhi Zeng, J. P. Oliveira, Bei Peng, Jiajia Shen, Caiwang Tan, Xiaoguo Song, Wentao Yan
Summary: This paper investigates the significant effects of melting modes on heat transfer and fluid flow in laser beam oscillating welding (LBOW), and their influence on welding quality and solidification microstructure. A computational fluid dynamics (CFD) model is developed to study LBOW of 2219 aluminum alloy under different welding modes. The results show that the melting mode changes from keyhole to conduction mode with increasing oscillating frequency. Our work provides a foundation for optimizing the LBOW process to achieve sound joints.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Nanoscience & Nanotechnology
Binqiang Li, Binbin Wang, Liang Wang, J. P. Oliveira, Ran Cui, Yanan Wang, Guoqiang Zhu, Jianxin Yu, Yanqing Su
Summary: In this study, a single solution treatment and solution/aging treatments were used to regulate the precipitation behavior, martensitic transformation, mechanical and functional properties of NiTi shape memory alloys fabricated by EBF3. The post-heat treatment conditions of 1000 oC for 10 hours solution treatment followed by 500 oC for 4 hours aging treatment resulted in the dissolution and interruption of elongated Ti4Ni2Ox oxides and transformation of nanoscale Ni4Ti3 precipitates. The martensite transformation process and the presence of R-phase affected the superelastic stability and recovery ratio of the alloy.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Nanoscience & Nanotechnology
Jiajia Shen, Priyanka Agrawal, Tiago A. Rodrigues, J. G. Lopes, N. Schell, Jingjing He, Zhi Zeng, Rajiv S. Mishra, J. P. Oliveira
Summary: Weldability studies on high entropy alloys are lacking, hindering their practical applications. In this study, an as-cast Fe42Mn28Co10Cr15Si5 metastable high entropy alloy was welded for the first time using gas tungsten arc welding. The effect of weld thermal cycle on the microstructure evolution was analyzed through various techniques. The results showed the evolution of microstructure across the joint and the influence of different strengthening effects on the material's local strength. The presence of a brittle nanosized sigma phase was found to contribute to premature failure in the joints during mechanical testing.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Review
Materials Science, Multidisciplinary
Douglas S. M. Serrati, Miguel A. Machado, J. P. Oliveira, Telmo G. Santos
Summary: The wire and arc additive manufacturing (WAAM) process combines the fusion and solidification of metal wire with electric arc to create and repair complex structures. However, the high number of depositions increases the likelihood of defects, and high temperatures and surface irregularity make inspection difficult. Recent studies have shown that non-destructive testing (NDT) based on different physical phenomena can significantly reduce the rejection rate, allowing for in-line repair and waste reduction.
Review
Materials Science, Multidisciplinary
Francisco B. Ferreira, Igor Felice, Isaque Brito, Joao Pedro Oliveira, Telmo Santos
Summary: Friction stir welding is widely used in various industries, and its variant, orbital friction stir welding, is particularly important in fundamental industries like oil and gas and aerospace. The development of new process parameters, tools, and ancillary mechanisms is necessary to ensure high-quality joints. This review assesses the current state of orbital friction stir welding and discusses key aspects of this technology.
Article
Materials Science, Multidisciplinary
Min Zheng, Jin Yang, Jiayi Xu, Jiawei Jiang, Hua Zhang, J. P. Oliveira, Xueqi Lv, Jing Xue, Zhuguo Li
Summary: A porous high entropy alloy (HEA) coating was prepared on a steel surface by vacuum sintering and used as a transition layer during dissimilar laser joining of Al to steel. The coating improved the wettability and spreadability of the molten filler wire on the substrate, resulting in increased brazed width and reduced contact angle. The use of the coating also led to the formation of a composite-like microstructure, gradient nanocrystalline layer, and improved fracture load and displacement in the laser joints.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Automation & Control Systems
Guilherme Gadelha de Sousa Figueiredo, Ivan Bezerra de Mello Picchi, Mathews Lima dos Santos, Edwar Andres Torres Lopez, Joao Pedro Oliveira, Tiago Felipe de Abreu Santos
Summary: Wire + arc additive manufacturing is a production technology for large-sized parts in heavy-duty industries. This study investigates the effects of arc frequency, traverse speed, and wire feed speed on the ferrite number and geometric characteristics of multi-layered 316LSi structures fabricated using wire + arc additive manufacturing. The study concludes that parameter optimization of pulsed-gas metal arc welding is crucial for controlling heat input and phase structure evolution of 316L stainless steel components.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2023)
Article
Chemistry, Physical
Francisco Werley Cipriano Farias, Valdemar R. Duarte, Igor Oliveira Felice, Joao da Cruz Payao Filho, Norbert Schell, Emad Maawad, J. Y. Li, Y. Zhang, T. G. Santos, J. P. Oliveira
Summary: The study indicates that the combination of in situ interlayer hot forging and post-deposition heat treatment can modify the typical microstructure of Ni-based superalloy 625 obtained by arc plasma directed energy deposition, resulting in finer grains and non-oriented condition. The PDHT induced significant recrystallization, grain refinement, and dissolution of deleterious phases. Conventional heat treatments applied to this superalloy are not suitable for optimizing microstructure features. In situ hot forging promotes static re-crystallization during PDHT and high-temperature PDHT meets grain size requirements.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
F. F. Conde, G. G. Ribamar, J. D. Escobar, A. L. Jardini, M. F. Oliveira, J. P. Oliveira, J. A. Avila
Summary: Maraging steel is sensitive to the precipitation of intermetallics during aging heat treatments. This study used EBSD to analyze the microstructures of maraging steel and found that solubilization of the steel resulted in a more homogeneous microstructure with new grain boundaries. Tempering heat treatments relieved martensite strain and increased band contrast values. Aging had a minimal impact on the EBSD analysis results.
MATERIALS CHARACTERIZATION
(2023)
Article
Nanoscience & Nanotechnology
Yanan Wang, Binbin Wang, Liangshun Luo, J. P. Oliveira, Binqiang Li, Hui Yan, Tong Liu, Junhao Zhao, Liang Wang, Yanqing Su, Jingjie Guo, Dayong Chen
Summary: This study evaluates the effects of using a reactive process atmosphere on additively manufactured FeCrAl oxide dispersion strengthened (ODS) steel. The evaluation includes investigating the oxygen/nitrogen content, geometric characteristics, stability of the molten pool, microstructural feature, second phase formation, and tensile properties. The results show that the use of reactive process gas allows for in-situ alloying and increased oxide formation. However, oxide agglomeration and coarsening also occur. Printing under the N2 process atmosphere alleviates these issues and improves the mechanical properties of the parts.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Engineering, Manufacturing
Samruddha Kokare, J. P. Oliveira, Radu Godina
Summary: The development of sustainable manufacturing solutions is gaining attention in the manufacturing sector due to increased awareness about climate change and the formulation of stricter environmental legislation. This study compares the environmental impact and production costs of different manufacturing approaches for a marine propeller, including subtractive CNC milling, Wire Arc Additive Manufacturing (WAAM), and Selective Laser Melting (SLM). Based on Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) models, WAAM is found to be the most environmentally and cost-efficient approach. The study also investigates the effect of key variables and provides parameters for sustainable performance. The methodology used in this study can be applied to other additive manufacturing processes and can assist practitioners in selecting the most sustainable approach for their products.
JOURNAL OF MANUFACTURING PROCESSES
(2023)
Article
Engineering, Manufacturing
Patrick L. Inacio, Francisco B. Ferreira, Pedro Vilaca, J. P. Oliveira, Telmo G. Santos
Summary: This paper scrutinizes the analysis of energy flow during FSW/P and finds that the majority of energy dissipates as heat into the tooling and clamping system. Only a small portion of energy is effectively used for welding/processing. The study suggests that selecting the right anvil material can enhance energy efficiency.
JOURNAL OF MANUFACTURING PROCESSES
(2023)