Article
Nanoscience & Nanotechnology
Pengliang Niu, Wenya Li, Chenggang Yang, Yuhua Chen, Daolun Chen
Summary: Low cycle fatigue tests were conducted on friction stir welded dissimilar aluminum alloy joints with different strain amplitudes, revealing that the positioning of base materials during FSW affected the fatigue resistance of joints. When 7075 aluminum alloy was placed on the advancing side, longer fatigue life was achieved. Fracture of fatigued specimens always occurred at the softer heat-affected zone on the 2024 side, with crack initiation from the specimen surface and crack propagation characterized by typical fatigue striations.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Metallurgy & Metallurgical Engineering
M. Agilan, G. Phanikumar, D. Sivakumar
Summary: 2XXX series aluminium alloys are widely used in propellant tanks of space launch vehicles. Friction stir welding was used to produce dissimilar joints between 2195 and 2219 alloys, with the effect of temperature on tensile properties investigated. Results showed that lower temperatures improved tensile properties significantly, and the use of 2195 alloy slightly increased the properties of the dissimilar joint compared to a similar joint with 2219 alloy. Placing 2219 at the advancing side during welding resulted in better properties compared to the retreating side.
WELDING IN THE WORLD
(2022)
Article
Materials Science, Multidisciplinary
Fanqi Yu, Yunqiang Zhao, Zhicheng Lin, Yugang Miao, Fei Zhao, Yingchun Xie
Summary: To overcome the problems of low precision and long test cycle in friction stir welding (FSW) process, a machine learning model based on backpropagation neural network (BPNN) was developed to optimize the FSW of 2195 aluminum alloys. A four-dimensional mapping relationship between welding parameters and mechanical properties of joints was established through data analysis and mining. Intelligent optimization of the welding process and prediction of joint properties were achieved. The prediction accuracy of the proposed method reached 92%, with the optimized welding parameters being 1810 rpm, 105 mm/min, and 3 kN for rotational speed, welding speed, and welding pressure, respectively. Under these conditions, the tensile strength of the joint was 415 MPa, deviating from the experimental value by 3.71%.
Article
Nanoscience & Nanotechnology
Lei Shi, Xiang Dai, Chunyan Tian, Chuansong Wu
Summary: A novel splat cooling assisted friction stir welding (SCaFSW) was proposed to achieve high-strength joints of 2195 Al-Li alloy. The use of splat cooling in friction stir welding reduced the welding temperature and fluidity of the plastic materials, resulting in a rough weld surface and even the formation of void defects. Compared to conventional FSW, the SCaFSW joint had finer grain size and higher dislocation density in the weld nugget zone. Splat cooling suppressed the dissolution of precipitates into the matrix and resulted in coarse residual precipitates in the weld nugget zone of SCaFSW joints. Additionally, splat cooling significantly increased the tensile strength but decreased the elongation of defect-free 2195 Al-Li alloy joints.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Alexander Kalinenko, Vasiliy Mishin, Ivan Shishov, Sergey Malopheyev, Ivan Zuiko, Vseslav Novikov, Sergey Mironov, Rustam Kaibyshev, Sheldon Lee Semiatin
Summary: The relationship between the temperature conditions during friction-stir welding, the stir-zone microstructure, and the thermal stability of welded aluminum-alloy 6061 joints was investigated. It was found that the stir-zone microstructure was unstable against abnormal grain growth during post-weld solution annealing. The abnormal grain growth developed rapidly, nearly completing during the heating process. Annealing behavior followed Humphrey's cellular-growth model in all welded conditions. Low-heat-input led to a competition between normal grain growth and abnormal grain growth, resulting in relatively small final grain size. High-heat-input conditions provided microstructural stability but triggered catastrophic grain coarsening. Remarkably, abnormal grain growth led to a rotation of the crystallographic texture in the stir zone.
MATERIALS CHARACTERIZATION
(2022)
Article
Chemistry, Physical
Chenghang Zhang, Guangjie Huang, Qing Liu
Summary: This study investigated the local corrosion behavior of TMAZ in dissimilar AA2024/7075 joints, revealing lower corrosion resistance and higher susceptibility to corrosion compared to the base materials. The corrosion pits in TMAZ are mainly related to specific alloy particles, acting as anode relative to the aluminum matrix.
Article
Engineering, Manufacturing
Yuhang Guo, Xuancheng He, Chaocheng Liu, Chenggang Wei, Rui Yang, Xuguang Dong
Summary: In this study, the effects of ultrasonic assisted friction stir welding (Ua-FSW) and heat pipe assisted friction stir welding (Ha-FSW) on the welding of 4 mm thick 7075 aluminum alloy were investigated. The results showed that both Ua-FSW and Ha-FSW effectively improved the weld forming, with better surface quality observed in Ha-FSW joints. The ultrasound flow effect and heat dissipation from the heat pipe controlled the temperature gradient, resulting in finer grain sizes. These assisted technologies had a greater impact on the thermomechanically affected zone (TMAZ) and heat-affected zone (HAZ), promoting subgrain formation and retention. Ha-FSW also significantly improved the elongation performance of the joints.
JOURNAL OF MANUFACTURING PROCESSES
(2023)
Article
Materials Science, Multidisciplinary
S. Ya. Betsofen, I. S. Zuiko, R. O. Kaibyshev, M. I. Gordeeva
Summary: A new X-ray approach was used to quantify second-phase precipitates in friction-stir welded 2519-T820 aluminum alloy. The stir zone material was found to contain a significant fraction of non-equilibrium theta' and theta '' phases. Based on this result, it was concluded that the widely accepted concept of FSW-induced precipitation phenomena is oversimplified and requires revision.
Article
Metallurgy & Metallurgical Engineering
Peng-liang Niu, Wen-ya LI, Yu-hua Chen, Qi-peng Liu, Dao-lun Chen
Summary: The location of the base material has little effect on the tensile properties of the joints, but significant impact on the exfoliation corrosion performance. By optimizing the base material location, dissimilar joints with superior exfoliation corrosion resistance can be achieved.
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
(2022)
Article
Materials Science, Multidisciplinary
P. L. Niu, W. Y. Li, D. L. Chen
Summary: The cyclic deformation behavior of friction-stir-welded dissimilar AA2024-T351 to AA7075-T65 aluminum alloy joints was evaluated through stepwise tests at different strain rates. It was found that the cyclic hardening capacity of the joints increased with decreasing strain rate, and the heat-affected zone of AA2024 side hardened significantly after cyclic deformation.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2021)
Article
Metallurgy & Metallurgical Engineering
I Vysotskiy, K. Kim, S. Malopheyev, S. Mironov, R. Kaibyshev
Summary: This study aimed to improve the superplastic ductility of friction-stir welded joints of ultrafine-grained (UFG) Al-Mg-Sc-Zr alloy. The UFG material was produced at elevated temperature to suppress abnormal grain growth, but the new approach resulted in a high fraction of low-angle boundaries, hindering grain-boundary sliding. Thus, superplastic deformation was primarily concentrated in the fully-recrystallized stir zone.
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
(2022)
Article
Engineering, Mechanical
Hao Dinh Duong, Masakazu Okazaki, Tra Hung Tran
Summary: The study revealed that the fatigue life of T-lap joints is significantly influenced by interface morphology, with the geometry and orientation of kissing bonds playing a crucial role in fatigue failure behavior. Fatigue cracks primarily initiated at the weld toe under skin-directional loading test, while they mainly originated at the KBs under stringer-directional loading test. The role of KBs geometry and orientation in enhancing stress intensity factors was also simulated and discussed.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Materials Science, Characterization & Testing
Miguel Delgado, R. Flores, C. Santana, Luis Reyes-Osorio
Summary: This study investigates the evaluation of tunnel defects in Al-7075 T6 sheets processed by friction stir welding (FSW) using computed tomography (CT) and the finite element method (FEM). The effects of axial force and temperature generated during FSW were assessed using different rotational and welding speeds. CT-scanned joints were reconstructed to show the forms, places, and levels of detected defects. The combination of CT and numerical results provides an in-depth understanding of material flow and defect formation during the friction process.
NONDESTRUCTIVE TESTING AND EVALUATION
(2023)
Article
Materials Science, Multidisciplinary
Y. Tao, Z. Zhang, P. Xue, D. R. Ni, B. L. Xiao, Z. Y. Ma
Summary: Friction stir welding (FSW) of 2198-T8 Al-Li alloys was conducted under both air cooling and water cooling conditions. Results showed that under air cooling condition, the heat affected zone had the lowest hardness and post weld artificial aging improved the joint hardness, while water cooling had little effect on hardness and joint strength.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Yuming Xie, Xiangchen Meng, Feifan Wang, Yimeng Jiang, Xiaotian Ma, Long Wan, Yongxian Huang
Summary: The corrosion behavior of friction stir welded Al-Cu alloy and Al-Cu-Li alloy joints was studied via various methods, with a focus on precipitation-driven corrosion mechanism. It was found that increasing welding speed to reduce heat input is an effective strategy to improve corrosion resistance in these joints.
Article
Materials Science, Composites
Jakob D. Hamilton, Srikanthan Ramesh, Ola L. A. Harrysson, Christopher D. Rock, Iris Rivero
Summary: Cryogenic mechanical alloying was used to fabricate aluminum matrix composite powder feedstock for additive manufacturing, with varying characteristics observed based on milling parameters. Powder metallurgy samples were fabricated to understand the reinforcement distribution and resulting strengthening post-sintering, showcasing the potential of cryomilling as an effective method for custom alloy powder production in powder bed fusion additive manufacturing.
JOURNAL OF COMPOSITE MATERIALS
(2021)
Article
Automation & Control Systems
Xiao Zhang, Weijun Shen, Vignesh Suresh, Jakob Hamilton, Li-Hsin Yeh, Xuepeng Jiang, Zhan Zhang, Qing Li, Beiwen Li, Iris V. Rivero, Hantang Qin
Summary: The study utilizes the direct energy deposition (DED) process for remanufacturing and repair, demonstrating the effectiveness of real-time monitoring of the printing process. The structured light system (SLS) and computed tomography (CT) are used to evaluate the repair process and quality, showing potential for improving DED repair quality and promoting automation in the manufacturing industry.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2021)
Review
Materials Science, Biomaterials
Samuel Gerdes, Srikanthan Ramesh, Azadeh Mostafavi, Ali Tamayol, Iris Rivero, Prahalada Rao
Summary: Biological additive manufacturing (Bio-AM) is a promising method for fabricating biological scaffolds with nano- to microscale resolutions and biomimetic architectures beneficial to tissue engineering applications. However, flaws introduced during fabrication can affect mechanical properties and lead to unpredictable biological responses from cells interacting with the defective scaffolds.
ACS BIOMATERIALS SCIENCE & ENGINEERING
(2021)
Article
Computer Science, Artificial Intelligence
Eric Weflen, Cameron A. MacKenzie, Iris V. Rivero
Summary: This research introduces an influence diagram based approach to estimating task lead times for Kanban project management in an Agile environment. The method aims to partially automate the estimation process and improve stakeholder communication by generating a cumulative distribution function for probabilistic estimates. A sensitivity analysis is conducted to understand how different factors influence lead times.
EXPERT SYSTEMS WITH APPLICATIONS
(2022)
Review
Cell Biology
Emily Lazarus, Paola Bermudez-Lekerika, Daniel Farchione, Taylor Schofield, Sloan Howard, Iskender Mambetkadyrov, Mikkael Lamoca, Iris V. Rivero, Benjamin Gantenbein, Christopher L. Lewis, Karin Wuertz-Kozak
Summary: Sulfated hydrogels play a crucial role in maintaining the phenotype of chondrocytes and chondrocyte-like cells, as well as in the sustained delivery of growth factors. Current research focuses on identifying and summarizing the knowledge about different sulfated hydrogels, highlighting their benefits in cartilage and disc research, and reviewing the biofabrication processes to ensure quality assurance.
Article
Engineering, Industrial
Eric Weflen, Jakob D. Hamilton, Samantha Sorondo, Ola L. A. Harrysson, Matthew C. Frank, Iris Rivero
Summary: This research investigates the impact of friction stir tool geometry on the formation of interlayer gaps and lap shear strength of the weld. The outcomes show that lap shear strength increases with increasing pin diameter, but does not have a strong relation to pin length. Interlayer gap size increases with pin length, but does not show a clear trend with pin diameter. The research suggests that the increase in lap shear strength is due to a change in weld cross-section rather than a material property change. This study will guide the selection of friction stir tool geometry for the hybrid manufacturing process and can be applied to any application where material deformation around a weld is undesirable.
Article
Engineering, Manufacturing
Jakob D. Hamilton, Samantha Sorondo, Andrew Greeley, Xiao Zhang, Denis Cormier, Beiwen Li, Hantang Qin, Iris Rivero
Summary: Directed energy deposition (DED) based remanufacturing utilizes the flexibility of additive manufacturing to add value to broken or worn components. However, the development of appropriate DED process conditions for bimetallic cast iron structures lags behind, as thermal stresses and porosity generated by high-temperature deposition hinder the qualification process.
JOURNAL OF MANUFACTURING PROCESSES
(2022)
Article
Engineering, Manufacturing
Srikanthan Ramesh, Chaitanya Mahajan, Sam Gerdes, Aniruddha Gaikwad, Prahalada Rao, Denis R. Cormier, Iris V. Rivero
Summary: A two-dimensional computational fluid dynamics model is used to study the aerodynamic phenomena of aerosol jet printed features. By solving governing equations and implementing a discrete phase model, the role of various flow parameters on the morphology of printed features is analyzed. The numerical results show good agreement with experimental measurements, providing a valuable tool for optimizing the printing process and predicting printing defects.
ADDITIVE MANUFACTURING
(2022)
Article
Engineering, Manufacturing
Jakob D. Hamilton, Samantha Sorondo, Beiwen Li, Hantang Qin, Iris Rivero
Summary: The utility of gray cast iron in engine components is influenced by mechanical performance and cost. Repairing and remanufacturing of castings offer economical and sustainable benefits, but traditional fusion-based welding fails to fully restore the original mechanical quality due to micro-structural defects. Directed energy deposition (DED) is an additive manufacturing method that shows promise for repairs due to its controllability. This study identifies optimal DED parameters for maximizing strength and fatigue life of repaired cast iron, and presents imaging and stress measurements to understand the metallurgical quality and strength achieved.
JOURNAL OF MANUFACTURING PROCESSES
(2023)
Article
Computer Science, Artificial Intelligence
Samuel Gerdes, Aniruddha Gaikwad, Srikanthan Ramesh, Iris V. Rivero, Ali Tamayol, Prahalada Rao
Summary: The goal of this work is to achieve flaw-free, industrial-scale production of biological additive manufacturing of tissue constructs. Two objectives were pursued in the context of extrusion-based Bio-AM of bone tissue constructs: (1) detecting flaw formation using in-situ infrared thermocouple sensors, and (2) preventing flaw formation through preemptive process control. Machine learning models were trained to classify and predict flaw formation, achieving an accuracy of nearly 90%. The trained models were also used for feedforward control, resulting in reduced strand width heterogeneity and consistent, repeatable production of Bio-AM constructs.
JOURNAL OF INTELLIGENT MANUFACTURING
(2023)
Article
Materials Science, Multidisciplinary
Jakob D. Hamilton, David Trauernicht, Denis Cormier, Iris V. Rivero
Summary: Directed energy deposition is an ideal method for restoring and remanufacturing cast iron components, but further research is needed to understand the consequence of filler material composition and form. This study provides microstructural and process-specific insights to support the observations and quantifies the structural characteristics of cast iron repairs. With appropriate thermal conditions, close to the original tensile strength of gray cast iron can be achieved in the repairs.
ADVANCED ENGINEERING MATERIALS
(2023)
Review
Biotechnology & Applied Microbiology
Emily Lazarus, Anne S. Meyer, Kaoru Ikuma, Iris V. Rivero
Summary: Three dimensional printing of biofilms has the potential to create complex microenvironments for cell constructs, making it an ideal strategy for tissue engineering and regenerative medicine. The use of bioinks and 3D bioarchitecture design are crucial in the fabrication process. The applications of 3D printed biofilms in biomedical and environmental fields are vast and promising.
MICROBIAL BIOTECHNOLOGY
(2023)
Article
Automation & Control Systems
Jakob D. Hamilton, Iris V. Rivero
Summary: In this study, in situ high-speed imaging is used to quantify the optimal thermal conditions for wire- and powder-based DED repair of gray cast iron. The insights provided by this research help in selecting superior parameters and can be extended to other difficult-to-repair materials.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2023)
Proceedings Paper
Engineering, Manufacturing
Xiao Zhang, Weijun Shen, Vignesh Suresh, Jakob Hamilton, Li-Hsin Yeh, Xuepeng Jiang, Zhan Zhang, Qing Li, Beiwen Li, Iris Rivero, Hantang Qin
Summary: The study applied Direct Energy Deposition (DED) process for remanufacturing and repair, using a structured light system to monitor real-time printing process, which improved repair quality, reduced repair time, and promoted repair automation.
49TH SME NORTH AMERICAN MANUFACTURING RESEARCH CONFERENCE (NAMRC 49, 2021)
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
Han Liu, Simon Laflamme, Eric M. Zellner, Sarah A. Bentil, Iris Rivero, Thomas W. Secord, Ali Tamayol
Summary: The study focuses on characterizing a soft elastomeric capacitor (SEC) for monitoring large levels of deformation in smart bandage applications. It was found that using corrugated surfaces significantly improves the sensor's sensitivity, linearity, and resolution, and can effectively monitor skin elongation. Experimental tests and numerical investigations show that corrugation can improve stress distribution on soft tissue around wounds, with the auxetic pattern performing the best among the corrugated patterns. The study demonstrates the promise of corrugated SEC as a smart bandage.
2021 IEEE INTERNATIONAL INSTRUMENTATION AND MEASUREMENT TECHNOLOGY CONFERENCE (I2MTC 2021)
(2021)
