The Experts below are selected from a list of 627 Experts worldwide ranked by ideXlab platform
Wenbin Hu - One of the best experts on this subject based on the ideXlab platform.
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microstructure modification and improving corrosion resistance of laser surface quenched Nickel Aluminum Bronze alloy
Corrosion Science, 2020Co-Authors: Yiwen Zhang, Yuting Lv, Zhong Wu, Wenbin HuAbstract:Abstract Laser surface quenching technology was utilized to modify the surface microstructure of as-cast Nickel-Aluminum Bronze. A supersaturated solid solution layer with a fine-grained size of 30∼50 μm was formed, and its corrosion behavior was studied by electrochemical measurements and long-term immersion corrosion test. It was found that laser surface quenching homogenized the distribution of elements in the constituent phases and eliminated the selective phase corrosion. Due to the formation of a more protective film on laser quenched NAB alloy, the corrosion rate reduced about 42.6 % compared with that of as-cast NAB alloy.
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microstructure design to improve the corrosion and cavitation corrosion resistance of a Nickel Aluminum Bronze
Corrosion Science, 2018Co-Authors: Qi Zhang, Zhong Wu, Bin Shen, Wenbin HuAbstract:Abstract Microstructure evolution of the Nickel-Aluminum Bronze alloy was studied by heat treatment, including annealing, normalizing, quenching and aging. The microstructure was refined and homogenized after quenching or quenching/aging at 450 ℃, which can eliminate selective phase corrosion effectively. Compared with the current production process, static corrosion rate reduced about 50%, due to the rapid formation of a protective film. In addition, cavitation corrosion rate reduced by a factor of 4.9 and 7.9 for the quenched and quenched/aged at 450 ℃ samples, respectively. This can be attributed to the improved hardness and weakened synergy between corrosion and mechanical attack.
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the corrosion behavior of ni cu gradient layer on the Nickel Aluminum Bronze nab alloy
Corrosion Science, 2018Co-Authors: Zhong Wu, Wenbin Hu, Bin ShenAbstract:Abstract The gradient Ni-Cu layer on Nickel Aluminum-Bronze alloy was obtained by the thermal diffusion process. The corrosion resistance was improved due to the formation of protective film, consisted of Ni(OH)2 and Cu2O. Although the Ni-Cu layer exhibited local corrosion with uniform corrosion and pitting corrosion simultaneously during the immersion test, the pitting growth was depressed because of the gradient distribution of Ni and Cu. The relieving driving force for galvanic corrosion between outer passive layer and bare Ni-Cu in the pitting was the main factor, which was caused by the decreasing interface potential drop.
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the synergistic effect of cavitation erosion and corrosion of Nickel Aluminum copper surface layer on Nickel Aluminum Bronze alloy
Journal of Alloys and Compounds, 2018Co-Authors: Qi Zhang, Zhong Wu, Wenbin Hu, Bin ShenAbstract:Abstract A completely Nickel-Aluminum-copper (Ni-Al-Cu) layer was obtained through thermal diffusion process on a Nickel-Aluminum-Bronze (NAB) substrate. The cumulative mass loss of the NAB alloy during the cavitation erosion tests was about 6.4 times and 5.5 times as large as that of the Ni-Al-Cu layer in distilled water and 3.5 wt% sodium chloride (NaCl), respectively. Electrochemical measurements under quiescence and cavitation erosion conditions were conducted to investigate the synergistic effects of cavitation erosion and corrosion. The results showed that the synergism had measurable effect on the cavitation erosion-corrosion process for both the NAB alloy and the Ni-Al-Cu layer. The total contribution of the cavitation erosion component including WE and WCIE was more than 80% and WE occupied the largest percentage. Thus, the improved cavitation erosion resistance of the Ni-Al-Cu layer was mainly due to mechanical factors, which implied a homogeneous and refined microstructure and the formation of hardened Ni3Al phase.
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surface modification of Nickel Aluminum Bronze alloy with gradient ni cu solid solution coating via thermal diffusion
Surface & Coatings Technology, 2017Co-Authors: Zhong Wu, Wenbin HuAbstract:Abstract The surface modification of Nickel-Aluminum Bronze (NAB) alloy was developed by thermal diffusion of Ni coating and the alloy matrix. A multilayer coating was designed with the gradient outer layer of the Ni-Cu solid solution and the inner layer of the Ni-Al-Cu intermetallic layer. The evolution of the multilayer was a diffusion controlled model. The enhanced corrosion resistance of the Ni-Cu layer could be found in the salt spray test, which exhibited uniform corrosion behavior compared with severe selective phase corrosion of the NAB alloy. Besides the gradient distribution of the components, it was also attributed to the formation of protective film, which mainly consisted of Ni(OH) 2 and Cu 2 O. It has been confirmed by electrochemical impedance spectroscopy (EIS) test and X-ray photoelectron spectroscopy (XPS) results.
Zhong Wu - One of the best experts on this subject based on the ideXlab platform.
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microstructure modification and improving corrosion resistance of laser surface quenched Nickel Aluminum Bronze alloy
Corrosion Science, 2020Co-Authors: Yiwen Zhang, Yuting Lv, Zhong Wu, Wenbin HuAbstract:Abstract Laser surface quenching technology was utilized to modify the surface microstructure of as-cast Nickel-Aluminum Bronze. A supersaturated solid solution layer with a fine-grained size of 30∼50 μm was formed, and its corrosion behavior was studied by electrochemical measurements and long-term immersion corrosion test. It was found that laser surface quenching homogenized the distribution of elements in the constituent phases and eliminated the selective phase corrosion. Due to the formation of a more protective film on laser quenched NAB alloy, the corrosion rate reduced about 42.6 % compared with that of as-cast NAB alloy.
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Evolution of the Corrosion Product Film on Nickel-Aluminum Bronze and Its Corrosion Behavior in 3.5 wt % NaCl Solution.
Materials, 2019Co-Authors: Yang Ding, Liqiang Wang, Rong Zhao, Zhong Wu, Weijie LuAbstract:The in-situ studies of the corrosion product film on Nickel-Aluminum Bronze are significant for explaining the mechanism of its corrosion resistance. In this paper, the corrosion behavior of Nickel-Aluminum Bronze and the formation process of the protective film in 3.5 wt % NaCl solution are systematically investigated. The results of scanning electron microscope analysis and electrochemical tests indicate that the corrosion resistance of Nickel-Aluminum Bronze is improved due to the formation of the corrosion product film. The change of local electrochemical property on the corrosion product film during the immersion time is evaluated via in-situ scanning vibrating electrode technique, and it reveals the evolution rules of ionic flux in real time. The formation process of the protective film on different phases in Nickel-Aluminum Bronze is observed directly by in-situ atomic force microscopy as height change measurements. The α phases at different locations present different corrosion behaviors, and the lamellar α phase within the α + κIII eutectoid structure gets more serious corrosion attack. The κ phases establish a stable and dense protective film in short time, preventing the corrosion attack effectively. The β′ phase, however, suffers the most serious corrosion damage until a protective film is formed after 150 min of immersion.
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evolution of the corrosion product film on Nickel Aluminum Bronze and its corrosion behavior in 3 5 wt nacl solution
Materials, 2019Co-Authors: Yang Ding, Liqiang Wang, Rong Zhao, Zhong Wu, Weijie LuAbstract:The in-situ studies of the corrosion product film on Nickel-Aluminum Bronze are significant for explaining the mechanism of its corrosion resistance. In this paper, the corrosion behavior of Nickel-Aluminum Bronze and the formation process of the protective film in 3.5 wt % NaCl solution are systematically investigated. The results of scanning electron microscope analysis and electrochemical tests indicate that the corrosion resistance of Nickel-Aluminum Bronze is improved due to the formation of the corrosion product film. The change of local electrochemical property on the corrosion product film during the immersion time is evaluated via in-situ scanning vibrating electrode technique, and it reveals the evolution rules of ionic flux in real time. The formation process of the protective film on different phases in Nickel-Aluminum Bronze is observed directly by in-situ atomic force microscopy as height change measurements. The α phases at different locations present different corrosion behaviors, and the lamellar α phase within the α + κIII eutectoid structure gets more serious corrosion attack. The κ phases establish a stable and dense protective film in short time, preventing the corrosion attack effectively. The β′ phase, however, suffers the most serious corrosion damage until a protective film is formed after 150 min of immersion.
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microstructure design to improve the corrosion and cavitation corrosion resistance of a Nickel Aluminum Bronze
Corrosion Science, 2018Co-Authors: Qi Zhang, Zhong Wu, Bin Shen, Wenbin HuAbstract:Abstract Microstructure evolution of the Nickel-Aluminum Bronze alloy was studied by heat treatment, including annealing, normalizing, quenching and aging. The microstructure was refined and homogenized after quenching or quenching/aging at 450 ℃, which can eliminate selective phase corrosion effectively. Compared with the current production process, static corrosion rate reduced about 50%, due to the rapid formation of a protective film. In addition, cavitation corrosion rate reduced by a factor of 4.9 and 7.9 for the quenched and quenched/aged at 450 ℃ samples, respectively. This can be attributed to the improved hardness and weakened synergy between corrosion and mechanical attack.
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the corrosion behavior of ni cu gradient layer on the Nickel Aluminum Bronze nab alloy
Corrosion Science, 2018Co-Authors: Zhong Wu, Wenbin Hu, Bin ShenAbstract:Abstract The gradient Ni-Cu layer on Nickel Aluminum-Bronze alloy was obtained by the thermal diffusion process. The corrosion resistance was improved due to the formation of protective film, consisted of Ni(OH)2 and Cu2O. Although the Ni-Cu layer exhibited local corrosion with uniform corrosion and pitting corrosion simultaneously during the immersion test, the pitting growth was depressed because of the gradient distribution of Ni and Cu. The relieving driving force for galvanic corrosion between outer passive layer and bare Ni-Cu in the pitting was the main factor, which was caused by the decreasing interface potential drop.
Liping Zhou - One of the best experts on this subject based on the ideXlab platform.
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wear triggered self healing behavior on the surface of nanocrystalline Nickel Aluminum Bronze ti 3 sic 2 composites
Applied Surface Science, 2018Co-Authors: Wenzheng Zhai, Wenlong Lu, Po Zhang, Jian Wang, Liping ZhouAbstract:Abstract Self-healing can protect materials from diverse damages, but is intrinsically difficult in metals. This paper demonstrates a potential method through a simultaneous decomposition and oxidation of Ti3SiC2 to achieve healing of stress cracking on the surface of Nickel Aluminum Bronze (NAB)/Ti3SiC2 nanocrystalline composites during fretting wear. At the finest nanocrystalline materials, a crack recovery would be attained at 76.5%. The repetitive fretting wear leads to a modest amount of ‘flowability’ of Ti3SiC2 toward the crack, facilitating crack recovery. Along with the wear-triggered self-healing, the NAB/Ti3SiC2 shows an improved tribological performance with the stable decreased friction torque due to the formation of lubrication TiO2 oxide.
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Wear-triggered self-healing behavior on the surface of nanocrystalline Nickel Aluminum Bronze/Ti 3 SiC 2 composites
Applied Surface Science, 2018Co-Authors: Wenzheng Zhai, Wenlong Lu, Po Zhang, Jian Wang, Liping ZhouAbstract:Abstract Self-healing can protect materials from diverse damages, but is intrinsically difficult in metals. This paper demonstrates a potential method through a simultaneous decomposition and oxidation of Ti3SiC2 to achieve healing of stress cracking on the surface of Nickel Aluminum Bronze (NAB)/Ti3SiC2 nanocrystalline composites during fretting wear. At the finest nanocrystalline materials, a crack recovery would be attained at 76.5%. The repetitive fretting wear leads to a modest amount of ‘flowability’ of Ti3SiC2 toward the crack, facilitating crack recovery. Along with the wear-triggered self-healing, the NAB/Ti3SiC2 shows an improved tribological performance with the stable decreased friction torque due to the formation of lubrication TiO2 oxide.
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effect of different levels of free water in oil on the fretting wear of Nickel Aluminum Bronze based composites
Wear, 2017Co-Authors: Wenlong Lu, Wenzheng Zhai, Po Zhang, Mingzhuo Zhou, Liping ZhouAbstract:Abstract Fretting wear of Nickel-Aluminum Bronze (NAB) alloys and 15 wt% Ti3SiC2/NAB composites against the 42CrMo4 steel was studied through flat-on-flat testing at oil-lubrication conditions with varying free-water contents (0, 26.8, 52.3 and 76.7 wt%). Tribological test results revealed that the addition of Ti3SiC2 substantially reduced the fretting wear and the friction coefficient of NAB alloys at all testing conditions, which could be attributed to high absorption of the fracture energy on the wear track by the deflection of fatigue cracks along Ti3SiC2/NAB interfaces. In addition, microstructural analyses and dissipative particle dynamics simulations revealed that high free-water contents facilitated the propagation of cracks and break of the oil film, which resulted in the transformation of wear mechanisms from abrasion and mild oxidation at the low free-water contents to abrasion, deformation and oxidation at the high contents. Accordingly, the steady-state friction coefficient of Ti3SiC2/NAB composites increased from 0.09 to 0.17 as the free-water content increased from 0 to 76.7 wt%.
Bingwen Lu - One of the best experts on this subject based on the ideXlab platform.
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effect of the protective materials and water on the repairing quality of Nickel Aluminum Bronze during underwater wet laser repairing
Optics and Laser Technology, 2019Co-Authors: Xiangru Feng, Wei Zheng, Bingwen Lu, Meiling Dong, Yao ZhaoAbstract:Abstract Today, many researchers focus on the destructive effects of the laser in underwater environment. In this paper, we present underwater wet laser repairing which is a kind of technique to avert the destructive effects of the interactions between laser, water and target. We introduce helpful materials to repair Nickel Aluminum Bronze (NAB) plate and discuss the effect of interactions between the laser, water and target on the repairing quality during underwater wet laser repairing process. As a result, the useful materials, Zn and Ti, protect melting pool from damaging by the high-speed water jet and shock wave. The as-repaired layers possess good repairing quality. In addition, the as-repaired layer manufactured by underwater wet laser repairing process possesses smaller heat affected zone, smaller coating thickness and more deformation than the layer manufactured in the air. In summary, with the help of the useful materials, a good repairing quality can be obtained.
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performance of underwater laser cladded Nickel Aluminum Bronze by applying zinc protective layer and titanium additives
Journal of Materials Processing Technology, 2019Co-Authors: Xiangru Feng, Wei Zheng, Yao Zhao, Bingwen Lu, Meiling DongAbstract:Abstract The requirement of repairing damaged surface of Nickel Aluminum Bronze (NAB) parts from underwater environment is urgent in recent years. In this paper, a novel approach to underwater laser cladded NAB by adding Ti and applying Zn protective layer has been reported. The materials fabricated underwater from this approach possess desirable performance. Ti additives increases the surface tension in melting pool, and prevents the high-speed water jet from invading the melting pool. Therefore, pores are almost disappearing. Due to the fast heat loss during underwater laser cladding process, the microstructure of underwater laser cladded Nickel Aluminum with adding titanium is fine, homogeneous and stable, in addition, the heat affected zone is small. Electrochemical results shows that the corrosion resistance of underwater laser cladded Nickel Aluminum Bronze with adding titanium is better than that of substrate. In this study, the underwater environment is favorable for manufacturing a good material by using laser processing technology. The results of this study will provide meaningful reference to repairing NAB parts in underwater environment.
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underwater laser cladding in full wet surroundings for fabrication of Nickel Aluminum Bronze coatings
Surface & Coatings Technology, 2018Co-Authors: Xiangru Feng, Wei Zheng, Bingwen LuAbstract:Abstract Underwater laser repairing technology as a new type of on-line maintenance technology will promote the development of oceanographic engineering. However, there are many difficulties during the process of underwater laser repairing. In this paper, underwater laser cladding process in full wet surroundings (or WULC, for short) for fabrication of Nickel Aluminum Bronze (or NAB, for short) has been reported, and laser cladding process in the air for fabricating NAB coatings was used for comparative study. The homemade protective covering was used to solve the problems of underwater laser repairing. For comprehending the effect of full wet surroundings and protective covering on microstructure and electrochemical performance of the NAB coatings, a series of characterization tests including SEM, EDS, XRD and TEM and a series of electrochemical measurements were carried out. The alloy coatings fabricated by WULC possess good formability through optimizing the processing parameters. The elements distribution of the coatings shows different patterns compared to conventional cast copper alloy and NAB coating fabricated by laser cladding in the air. In addition, the ordered solid solution and twinning structure have been observed in the WULC-NAB coatings. These unique microstructures and elements distribution patterns caused the better electrochemical performance of NAB coating fabricated by WULC. These findings suggest that the idea of using a protective layer in underwater laser cladding in full wet surroundings is feasible. The WULC process reported in this paper can provide some theoretical guidance for repairing damaged parts in full wet surroundings.
Babak Shalchi Amirkhiz - One of the best experts on this subject based on the ideXlab platform.
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micromechanical characterization of wire arc additive manufactured and cast Nickel Aluminum Bronze ambient and intermediate temperatures
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2020Co-Authors: S I Shakil, Chalasani Dharmendra, Babak Shalchi Amirkhiz, Mohsen Mohammadi, D Verma, M HaghshenasAbstract:Abstract Instrumented indentation is a semi-destructive and robust technique to assess micromechanical characteristics (e.g., local properties) of metallic materials at ambient and elevated temperatures. In the present study, the instrumented indentation is employed to assess and compare the micromechanical response and fundamental mechanisms of plastic deformation (e.g., rate-controlling plasticity) in wire-arc additively manufactured (WAAM) and cast Nickel Aluminum Bronze (Cu–9Al–4Fe–4Ni–1Mn) at ambient and intermediate temperatures. Two separate sets of indentation-based test schedules are employed to investigate these mechanisms. In the first set of experiments, load-controlled (peak load of 500 mN) indentation tests are performed under various loading rates (5–50 mN/s) at a constant (25 °C) temperature. In the second set of experiments, load-controlled indentation tests (peak load of 200 mN) at various temperatures of 25, 200, and 300 °C are performed under a constant loading rate. Indentation load versus indentation depth and time data are analyzed to collect a wealth of information including indentation stress, indentation strain rate, size effect, dislocation activation energy, and activation volume to assess fundamentals of governing mechanisms of plastic deformation. Optical, scanning, and transmission electron microscopy are utilized to provide microstructural evidence for the proposed micromechanical mechanisms of plastic deformation based on dislocation activities and interactions. The nanoindentation hardness results show that the strength of the WAAM alloy is higher than the cast counterpart. However, neither cast nor WAAM-NAB materials are rate-sensitive at ambient (room) temperature. When the temperature is raised, both alloys become softer, and the indentation size effect becomes less pronounced. The activation volume and the activation energy data show that a steady-state microstructure does not necessarily exist around the indentations, and the nature of rate-limiting obstacles (against dislocation activities) may vary in the course of the indentation.
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microstructural evolution and mechanical behavior of Nickel Aluminum Bronze cu 9al 4fe 4ni 1mn fabricated through wire arc additive manufacturing
Additive manufacturing, 2019Co-Authors: Chalasani Dharmendra, Amir Hadadzadeh, Babak Shalchi Amirkhiz, Mohsen MohammadiAbstract:Abstract As a step forward toward the development of the next generation of Nickel Aluminum Bronze (NAB) components using wire-arc additive manufacturing (WAAM), square bars were printed in the vertical direction. The as-built microstructure was characterized using multi-scale electron microscopy techniques, where the differences in phase formation were compared to the reference cast-NAB based on the solidification characteristics. The as-cast microstructure typically consists of Cu-rich α-matrix, and four types of intermetallic particles referred to as κ-phases. In the WAAM-NAB, the formation of κI was suppressed due to high cooling rates. The microstructure was finer and the volume fraction of intermetallic particles was significantly lower than that of the cast-NAB. Based on energy dispersive spectroscopy (EDS) technique and diffraction pattern analysis using transmission electron microscopy (TEM), the phases formed in the interdendritic regions were identified as κII (globular Fe3Al) and κIII (lamellar NiAl), whereas numerous fine (5–10 nm) Fe-rich κIV particles were precipitated uniformly within the α-matrix. Electron backscatter diffraction analysis revealed weak texture on both parallel and perpendicular planes to the building direction with (100) poles rotated away from the build direction. The WAAM-NAB sample exhibited considerably higher yield strength (˜88 MPa) and elongation (˜10%) than the cast-NAB, but the gain in the ultimate tensile strength was marginal.
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The Morphology, Crystallography, and Chemistry of Phases in Wire-Arc Additively Manufactured Nickel Aluminum Bronze
TMS 2019 148th Annual Meeting & Exhibition Supplemental Proceedings, 2019Co-Authors: Chalasani Dharmendra, Amir Hadadzadeh, Babak Shalchi Amirkhiz, Mohsen MohammadiAbstract:A new Wire-Arc Additive Manufacturing Additive manufacturing (WAAM) technique is used to produce Nickel Aluminum Bronze (NAB) Nickel Aluminum Bronze (NAB) components for marine applications Applications in view to mitigate the problems that typically arise in a cast microstructure Microstructure . In cast condition, the alloy typically exhibits microstructure Microstructure that consists of an FCC Cu-rich solid solution (or α-phase), some retained β-phase, and several intermetallic phases Intermetallic phases collectively referred to as κ-phase. This study aims to characterize the crystal structures of the various κ-phases or precipitates, their distribution, morphology, orientation relationships with the α-matrix, and their chemical compositions in WAAM-NAB Nickel Aluminum Bronze (NAB) alloy using electron microscopy Electron microscopy . The precipitation Precipitation of κ-phase differs in morphology and chemical composition to those present in a cast NAB Nickel Aluminum Bronze (NAB) . In addition, some uniaxial tensile coupons were machined out of the WAAM-NAB Nickel Aluminum Bronze (NAB) samples, where tensile mechanical properties Mechanical properties are superior to those of cast NAB Nickel Aluminum Bronze (NAB) . The effects of microstructural differences in both alloys on the mechanical properties Mechanical properties are correlated.
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the morphology crystallography and chemistry of phases in wire arc additively manufactured Nickel Aluminum Bronze
2019Co-Authors: Chalasani Dharmendra, Amir Hadadzadeh, Babak Shalchi Amirkhiz, Mohsen MohammadiAbstract:A new Wire-Arc Additive Manufacturing (WAAM) technique is used to produce Nickel Aluminum Bronze (NAB) components for marine applications in view to mitigate the problems that typically arise in a cast microstructure. In cast condition, the alloy typically exhibits microstructure that consists of an FCC Cu-rich solid solution (or α-phase), some retained β-phase, and several intermetallic phases collectively referred to as κ-phase. This study aims to characterize the crystal structures of the various κ-phases or precipitates, their distribution, morphology, orientation relationships with the α-matrix, and their chemical compositions in WAAM-NAB alloy using electron microscopy. The precipitation of κ-phase differs in morphology and chemical composition to those present in a cast NAB. In addition, some uniaxial tensile coupons were machined out of the WAAM-NAB samples, where tensile mechanical properties are superior to those of cast NAB. The effects of microstructural differences in both alloys on the mechanical properties are correlated.