Article
Chemistry, Physical
H. Karimialavijeh, M. Ghasri-Khouzani, A. Chakraborty, M. Proebstle, E. Martin
Summary: This study investigates the effect of direct aging on a newly developed high-performance aluminum alloy A20X for laser powder bed fusion. It is found that direct aging can cause softening of the material, and the extent of softening is proportional to the temperature and duration of heat treatment. During direct aging, the precipitate size grows and no metastable precipitates are formed. Moreover, the presence of solute walls in the as-printed state leads to unstable plastic flow, while longer aging treatments promote smoother plastic flow.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Richard A. Michi, Sumit Bahl, Christopher M. Fancher, Kevin Sisco, Lawrence F. Allard, Ke An, Dunji Yu, Ryan R. Dehoff, Alex Plotkowski, Amit Shyam
Summary: The high-temperature deformation behavior of an additively manufactured Al-Cu-Mn-Zr alloy is investigated through ex-situ and in-situ neutron diffraction creep experiments at 300 degrees C. The dominant reinforcement phase in the alloy, theta-Al2Cu, does not contribute to load transfer strengthening during creep deformation. Instead, a load shuffling mechanism is observed where the initial load is transferred from precipitate-free zones to precipitate-strengthened grain interiors. Despite lacking load transfer strengthening, the as-fabricated AM Al-Cu-Mn-Zr alloy shows improved creep resistance compared to a cast alloy with similar composition. The proposed load shuffling mechanism explains the absence of L1(2)-Al3Zr strengthening at 300 degrees C and suggests strategies for enhancing the elevated-temperature mechanical response of AM Al alloys.
Article
Materials Science, Multidisciplinary
Richard A. Michi, Kevin Sisco, Sumit Bahl, Ying Yang, Jonathan D. Poplawsky, Lawrence F. Allard, Ryan R. Dehoff, Alex Plotkowski, Amit Shyam
Summary: This paper reports on a novel additively manufactured aluminum alloy that exhibits excellent creep resistance compared to cast high-temperature aluminum alloys at 300-400 degrees C. The alloy is characterized by a high volume fraction of submicron intermetallic strengthening phases, which remain resistant to coarsening for hundreds of hours at 350 degrees C.
Article
Materials Science, Multidisciplinary
Ayda Shahriari, Dharmendra Chalasani, Babak Shalchi Amirkhiz, Mohsen Mohammadi
Summary: This study examined the corrosion performance of Nickel-aluminum bronzes (NAB) fabricated by wire arc additive manufacturing (WAAM) and casting methods, finding that WAAM samples showed superior corrosion resistance in chloride solution. Heat treatment also affected the microstructural characteristics and corrosion resistance of the NAB samples.
NPJ MATERIALS DEGRADATION
(2023)
Article
Engineering, Manufacturing
Priyanka Agrawal, Sanya Gupta, Saket Thapliyal, Shivakant Shukla, Ravi Sankar Haridas, Rajiv S. Mishra
Summary: In-depth analysis of the microstructure of an AM alloy revealed promising properties for structural applications, with improved strength and ductility due to the presence of precipitates. The study utilized advanced microscopy techniques to study the microstructure and understand the mechanisms behind the enhanced tensile properties.
ADDITIVE MANUFACTURING
(2021)
Article
Materials Science, Multidisciplinary
Robert K. Rhein, Qianying Shi, Srinivasan Arjun Tekalur, J. Wayne Jones, Jason W. Carroll
Summary: The study focused on the high cycle fatigue behavior of an additively manufactured aluminum alloy, AlSi10Mg-T6, specifically examining the impact of process-related defects on fatigue life, initiation, and small crack propagation behavior. Ultrasonic fatigue methods were used to determine effective fatigue strength for lifetimes in the range of 10^8-10^9 cycles. X-ray CT imaging was utilized to detect crack initiation and growth during fatigue cycling, revealing slow crack growth rates and transgranular, non-crystallographic behavior in small cracks originating from surface defects.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2021)
Article
Chemistry, Physical
X. X. Zhang, A. Lutz, H. Andra, M. Lahres, W. Gong, S. Harjo, C. Emmelmann
Summary: The ductility of AM Al alloys is crucial in the automotive industry. Post-annealing treatment improves ductility, but the plastic deformation mechanisms of annealed AM AlSi3.5Mg2.5 alloy are unclear. In this study, in-situ neutron diffraction was used to analyze the stress, dislocation density, and crystallite size during deformation, revealing the evolution and establishing physical constitutive equations.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Grzegorz Struzikiewicz, Andrzej Sioma
Summary: This research investigates the quality issues related to selective laser sintering of AlSi10Mg alloy powder after milling, analyzing the influence of cutting parameters on surface quality and recommending an appropriate machining method for this type of alloy.
Article
Materials Science, Multidisciplinary
Sumit Bahl, Alex Plotkowski, Kevin Sisco, Donovan N. Leonard, Lawrence F. Allard, Richard A. Michi, Jonathan D. Poplawsky, Ryan Dehoff, Amit Shyam
Summary: The study found that the Al-9Cu-6Ce alloy fabricated by laser powder bed fusion exhibited a decrease in tensile elongation at elevated temperatures, accompanied by the progression of strain localization in the heat affected zone leading to failure. However, at other temperatures, a higher strain-rate sensitivity (SRS) improved the tensile elongation.
Article
Nanoscience & Nanotechnology
Xuewei Fang, Lijuan Zhang, Guopeng Chen, Ke Huang, Fei Xue, Lei Wang, Jiyuan Zhao, Bingheng Lu
Summary: This paper investigates the effects of interlayer deformation on the mechanical properties, microstructural evolution, and strengthening mechanism of aluminum alloy components fabricated through additive manufacturing. It is found that interlayer hammering can result in grain refinement and contribute to an increase in ultimate tensile strength.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Aiden A. Martin, Joshua A. Hammons, Hunter B. Henderson, Nicholas P. Calta, Michael H. Nielsen, Caitlyn C. Cook, Jianchao Ye, Alyssa A. Maich, Nicholas E. Teslich, Tian T. Li, Michael J. Thompson, Matthew F. Besser, Manyalibo J. Matthews, Ryan T. Ott, Orlando Rios, Scott K. McCall, Trevor M. Willey, Jonathan R. Lee
Summary: The primary focus of metal additive manufacturing research has been on developing strategies for fabricating complex structures and optimizing microstructure. New alloys that exploit rapid solidification conditions are needed to overcome challenges in traditional aluminum alloys. Laser-induced melting of Al-8Ce-10Mg alloy has been shown to generate nanoscale microstructures, improving hardness and tensile strength while mitigating solidification cracking.
APPLIED MATERIALS TODAY
(2021)
Article
Nanoscience & Nanotechnology
S. Shakil, A. S. Zoeram, H. Pirgazi, B. Shalchi-Amirkhiz, B. Poorganji, M. Mohammadi, M. Haghshenas
Summary: This study investigates the processing-structure-property correlation of a high-strength titanium-modified aluminum copper alloy in laser powder-bed fusion (LPBF) and casting conditions. The effects of different heat-treatment processes on the alloy's properties were evaluated. The results show that fine equiaxed grains in the as-built condition greatly enhance the mechanical properties, and heat treatment has a more significant impact on the cast samples.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Engineering, Manufacturing
Pin Yang, Kyle L. Johnson, Jay D. Carroll, Jessica L. Buckner, Mia A. Blea-Kirby, Catherine Groves, Eric N. Coker
Summary: This study measured the thermophysical properties of additively manufactured and heat-treated Ti-5553 alloy, and compared them to microstructural features. The results indicate that processing and heat treatment variations have little impact on the thermal conductivity of the alloy, presumably due to its heavy alloying effect.
ADDITIVE MANUFACTURING
(2023)
Article
Engineering, Manufacturing
C. J. T. Mason, R. Rodriguez, D. Z. Avery, B. J. Phillips, B. P. Bernarding, M. B. Williams, S. D. Cobbs, J. B. Jordon, P. G. Allison
Summary: Solid-state additive manufacturing methods were used to quantitatively assess the influence of process parameters on the microstructural evolution and mechanical response of an aluminum alloy 7050 component. The study highlighted the impact of thermomechanical histories during Additive Friction Stir Deposition (AFS-D) on microstructure, and observed spatially dependent tensile properties due to heat input variation. Post-mortem analysis revealed voids nucleated and coalesced from overgrowth of strengthening precipitates, leading to fracture in the material.
ADDITIVE MANUFACTURING
(2021)
Article
Engineering, Civil
Krishna Prasath Logakannan, Dong Ruan, Jayaganthan Rengaswamy, S. Kumar, Velmurugan Ramachandran
Summary: Fracture occurs in cellular structures due to localized complex stress and/or strain state, making it difficult to accurately predict failure using traditional testing methods and finite element analysis. The build orientation of different ligaments also significantly affects the macroscopic performance of cellular structures. In order to improve numerical predictions, the failure strain should be considered in relation to stress triaxiality and build orientation. Experimental determination of fracture loci in AlSi10Mg alloy fabricated using Laser Powder Bed Fusion (LPBF) for different build orientations helps in developing predictive capabilities. Numerical models considering triaxial fracture loci provide more accurate predictions of deformation mode and fracture location in re-entrant structures compared to models that assume simple uniaxial tensile failure.
THIN-WALLED STRUCTURES
(2023)
Article
Nanoscience & Nanotechnology
Derui Jiang, Xiang Gao, Yuman Zhu, Christopher Hutchinson, Aijun Huang
Summary: This study investigated the microstructure and mechanical properties of additively manufactured 25Cr SDSS using metal powder based DLD. The results showed that DLD produced 25Cr SDSS had a balanced duplex structure and exhibited superior tensile strength compared to the commercial wrought alloy.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Review
Materials Science, Multidisciplinary
Wen Hao Kan, Louis Ngai Sam Chiu, Chao Voon Samuel Lim, Yuman Zhu, Yang Tian, Derui Jiang, Aijun Huang
Summary: Laser powder bed fusion is a promising additive manufacturing technique known for its ability to fabricate intricate components with minimal material wastage, yet it faces challenges such as porosity and poor repeatability. Research has been focused on understanding how porosity affects mechanical properties of alloys fabricated this way to aid in safe design and application of components.
JOURNAL OF MATERIALS SCIENCE
(2022)
Article
Microscopy
Meng-jia Li, Shuo Liu, Xiang-dong Wang, Yun-jia Shi, Qing-lin Pan, Xiao-jie Zhou, Rui-feng Zhang, Nick Birbilis
Summary: The influence of Sc and Zr on sensitization and intergranular corrosion in Al-5.8Mg-0.4Mn alloy was investigated. Results show that the addition of Sc and Zr improves the strength and intergranular corrosion resistance of the alloy. The presence of Al-3(Sc1-xZrx) dispersoids alters the proportion of low angle grain boundaries and decreases the volume fraction of beta-phase in the alloy.
Article
Materials Science, Multidisciplinary
Abdelmoheiman Zakaria Benbouzid, Maurilio Pereira Gomes, Isolda Costa, Oumaima Gharbi, Nadine Pebere, Jesualdo Luiz Rossi, Mai T. T. Tran, Bernard Tribollet, Mireille Turmine, Vincent Vivier
Summary: This study investigates the electrochemical impedance diagrams of a Mg electrode in a sodium sulfate solution at different pH values. A comprehensive model, independent of the pH range, is proposed to explain the singular behavior of Mg at low pH values, taking into account the presence of two adsorbed intermediates. The study also reveals that in acidic media, both the double layer and cathodic partial reaction should be considered, while at higher pH values, the oxide/hydroxide layer significantly slows down the magnesium corrosion rate.
Article
Engineering, Multidisciplinary
Maurilio Pereira Gomes, Samantha Michelle Gateman, Isolda Costa, Oumaima Gharbi, Kieu Ngo, Jesualdo Luiz Rossi, Mireille Turmine, Vincent Vivier
Summary: A new experimental setup for local electrochemical impedance spectroscopy (LEIS) has been developed, allowing for measurements over a wide frequency range, including the low frequency domain. The setup includes improved signal treatment and a unique three-electrode LEIS probe, enabling reliable and time-sensitive measurements in various fields.
Review
Chemistry, Physical
Samantha Michelle Gateman, Oumaima Gharbi, Hercilio Gomes de Melo, Kieu Ngo, Mirelle Turmine, Vincent Vivier
Summary: This article presents different techniques for experimentally determining the interfacial capacitance of an electrode for supercapacitor efficiency quantification. It discusses the apparent differences between the values obtained from cyclic voltammetry and electrochemical impedance spectroscopy analysis and the errors that can result from using constant phase element (CPE) analysis.
CURRENT OPINION IN ELECTROCHEMISTRY
(2022)
Review
Chemistry, Physical
Junsoo Han, Oumaima Gharbi
Summary: This review discusses the extent to which current theoretical models and techniques used in corrosion science can be applied to new alloy systems, and outlines some of the challenges that need to be overcome.
CURRENT OPINION IN ELECTROCHEMISTRY
(2022)
Article
Materials Science, Multidisciplinary
U. Martin, N. Birbilis, D. D. Macdonald, D. M. Bastidas
Summary: The passivity breakdown and subsequent stress corrosion cracking (SCC) of Type 2001 lean duplex stainless steel (UNS S32001) reinforcement in a highly alkaline environment containing chlorides at a low temperature were investigated. Through electrochemical analysis, mechanical testing, and fractographic analysis, it was found that the chloride threshold for passivity breakdown in this environment is below 4 wt% Cl-. Stress higher than σy triggers pit initiation and crack nucleation, resulting in a low-frequency peak of the cracking process. The importance rating for the steel is 9 out of 10.
Article
Materials Science, Multidisciplinary
Baojie Dou, Xuejie Li, Junsoo Han, Nick Birbilis, Kevin Ogle
Summary: Hydrogen evolution, magnesium dissolution, and electron exchange were monitored in real time during anodic and cathodic polarization of magnesium in 0.1 M NaCl. The anodic charge correlated with magnesium dissolution, while hydrogen formation was independent and led to insoluble magnesium(II) formation. Increased iron impurity promoted hydrogen evolution but was not necessary for the negative difference effect. Electrochemical dissolution occurred across an intact magnesium(II)-based film, while hydrogen evolution occurred in regions where the film breaks down induced by anodic polarization.
Article
Nanoscience & Nanotechnology
Derui Jiang, Yang Tian, Yuman Zhu, Shuai Huang, Aijun Huang
Summary: This study demonstrates the feasibility of using a core-shell approach combined with hot isostatic pressing (HIP) to improve the productivity of laser powder bed fusion (LPBF) process for producing Hastelloy-X (HX) components. The core-shell HX with HIP treatment shows a grain size gradient from shell to core, leading to better mechanical properties compared to the HX without the core-shell structure. Moreover, the core-shell approach significantly improves the LPBF production rate.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Engineering, Manufacturing
Huikai Li, Erin G. Brodie, Christopher Hutchinson
Summary: An advantage of LPBF is the ability to create complex components easily. Most studies focus on commercially available powders, neglecting new alloy design. Mixing powders with different chemistries is an effective way to access new alloy compositions. This study extends a previously published model to describe the chemical distribution of LPBF material from mixed powders, incorporating remelting process and comparing it with experiments.
ADDITIVE MANUFACTURING
(2023)
Article
Materials Science, Multidisciplinary
Ninad Bhat, Amanda S. Barnard, Nick Birbilis
Summary: The widespread use of aluminium alloys in aerospace, transport and marine industries can be attributed to their desirable physical properties. Understanding the relationship between alloy composition, microstructure and mechanical properties is complex. Machine learning has proven to be a valuable tool in designing new alloys. This study utilizes a data-driven partitioning scheme to train individual regressors, which outperforms traditional domain knowledge-based partitioning, leading to increased model accuracy and interpretability.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Editorial Material
Chemistry, Physical
Christopher Hutchinson
Summary: Additively manufactured AlSi10Mg alloy exhibits high fatigue strength, comparable to its tensile strength, especially for micro-sized samples, due to the fine cells in its inherent three-dimensional network acting as cages to restrict damage accumulation.
Article
Metallurgy & Metallurgical Engineering
M. Ghorbani, M. Boley, P. N. H. Nakashima, N. Birbilis
Summary: This work proposes a new approach that utilizes data science to analyze the existing data in the field of Mg-alloy design. Through the development of a consolidated alloy database and the implementation of clustering using machine learning, the effects of alloying and thermomechanical processing on mechanical properties were explored, and the relationships between microstructure and mechanical properties were understood. This work introduces an invaluable open-source database and provides insights for future accelerated digital Mg-alloy design.
JOURNAL OF MAGNESIUM AND ALLOYS
(2023)
Article
Materials Science, Multidisciplinary
Xiaohan Weng, Yuxiang Wu, Jie Luo, Christopher Hutchinson
Summary: A new type of microstructure design concept for high strength steels, involving a nanolaminate structure of martensite and austenite, has been proposed using a method called 'chemical patterning'. A computational model has been developed to simulate the chemical patterning process and has been successfully used to design two chemically-patterned alloys with different levels of retained austenite. Experimental results confirm the effectiveness of this approach and demonstrate the interesting performance of the new microstructures.
