Zhuoyu Zhang, Lijia Zhong, Mingwei Lin, Ri Lin and Dejun Li
Docking technology plays a crucial role in enabling long-duration operations of autonomous underwater vehicles (AUVs). Visual positioning solutions alone are susceptible to…
Abstract
Purpose
Docking technology plays a crucial role in enabling long-duration operations of autonomous underwater vehicles (AUVs). Visual positioning solutions alone are susceptible to abnormal drift values due to the challenging underwater optical imaging environment. When an AUV approaches the docking station, the absolute positioning method fails if the AUV captures an insufficient number of tracers. This study aims to to provide a more stable absolute position visual positioning method for underwater terminal visual docking.
Design/methodology/approach
This paper presents a six-degree-of-freedom positioning method for AUV terminal visual docking, which uses lights and triangle codes. The authors use an extended Kalman filter to fuse the visual calculation results with inertial measurement unit data. Moreover, this paper proposes a triangle code recognition and positioning algorithm.
Findings
The authors conducted a simulation experiment to compare the underwater positioning performance of triangle codes, AprilTag and Aruco. The results demonstrate that the implemented triangular code reduces the running time by over 70% compared to the other two codes, and also exhibits a longer recognition distance in turbid environments. Subsequent experiments were carried out in Qingjiang Lake, Hubei Province, China, which further confirmed the effectiveness of the proposed positioning algorithm.
Originality/value
This fusion approach effectively mitigates abnormal drift errors stemming from visual positioning and cumulative errors resulting from inertial navigation. The authors also propose a triangle code recognition and positioning algorithm as a supplementary approach to overcome the limitations of tracer light positioning beacons.
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Sun Chengwen, Li Wei and Kong Dejun
This paper aims to investigate the effect of Ti3SiC2 on the high-temperature tribological behaviors of NiCr coating, which was beneficial to improve the friction-wear performance…
Abstract
Purpose
This paper aims to investigate the effect of Ti3SiC2 on the high-temperature tribological behaviors of NiCr coating, which was beneficial to improve the friction-wear performance of hot work mold.
Design/methodology/approach
NiCr-Ti3SiC2 coatings were prepared on H13 steel substrate by laser cladding. The microstructure, phases and hardness of obtained coatings were analyzed using a super-depth of field microscope, X-ray diffraction and microhardness tester, respectively, and the tribological performance of obtained coatings at 500°C was investigated using a high-temperature tester.
Findings
The results show the NiCr-Ti3SiC2 coatings are comprised of γ-Ni solid, solution, TixNiy, TiC and Ti3SiC2 phases, and the coating hardness is increased with the increase of Ti3SiC2 mass fraction, which is contributed to the fine-grain and dispersion strengthening effect by the addition of Ti3SiC2. The NiCr-Ti3SiC2 coatings present excellent friction reduction and wear resistance by the synergetic action of Ti3SiC2 lubricant and hard phase, and the wear mechanism is predominated by abrasive wear and oxidation wear.
Originality/value
Ti3SiC2 phase was used to reinforce the tribological performance of H13 steel at high temperature, and the roles of friction reduction and wear resistance were discussed.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2023-0004/
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Kong Dejun and Li Jiahong
The purpose of this paper is to evaluate the salt spray corrosion (SSC) and electrochemical corrosion performances of CrNi, TiAlN/NiCr and CrNi–Al2O3–TiO2 coatings on H13 steel…
Abstract
Purpose
The purpose of this paper is to evaluate the salt spray corrosion (SSC) and electrochemical corrosion performances of CrNi, TiAlN/NiCr and CrNi–Al2O3–TiO2 coatings on H13 steel, which improved the corrosion resistance of H13 hot work mold.
Design/methodology/approach
CrNi, TiAlN/NiCr and CrNi–Al2O3–TiO2 coatings were fabricated on H13 hot work mold steel using a laser cladding and cathodic arc ion plating. The SSC and electrochemical performances of obtained coatings were investigated using a corrosion test chamber and electrochemical workstation, respectively. The corrosion morphologies, microstructure and phases were analyzed using an electron scanning microscope, optical microscope and X-ray diffraction, respectively, and the mechanisms of corrosion resistance were also discussed.
Findings
The CrNi coating is penetrated by corrosion media, producing the oxide of Fe3O4 on the coating surface; and the TiAlN coating is corroded to enter into the CrNi coating, forming the oxides of TiO and NiO, the mechanism is pitting corrosion, whereas the CrNi–Al2O3–TiO2 coating is not penetrated, with no oxides, showing the highest SSC resistance among the three kinds of coatings. The corrosion potential of CrNi coating, TiAlN/CrNi and CrNi–Al2O3–TiO2 coatings was –0.444, –0.481 and –0.334 V, respectively, and the corresponding polarization resistances were 3,074, 2,425 and 86,648 cm2, respectively. The electrochemical corrosion resistance of CrNi–Al2O3–TiO2 coating is the highest, which is enhanced by the additions of Al2O3 and TiO2.
Originality/value
The CrNi, TiAlN/CrNi and CrNi–Al2O3–TiO2 coatings on H13 hot work mold were firstly evaluated by the SSC and electrochemical performances.
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Li Wei and Kong Dejun
The purpose of this study is to investigate the effect of Y2O3 mass fraction on the electrochemical corrosion performance of CrNi coating, which provided a foundation for the…
Abstract
Purpose
The purpose of this study is to investigate the effect of Y2O3 mass fraction on the electrochemical corrosion performance of CrNi coating, which provided a foundation for the performance optimization of CrNi coatings.
Design/methodology/approach
CrNi coatings with the different Y2O3 mass fractions were fabricated on AISI H13 steel by laser cladding, and the effect of Y2O3 mass fraction on the electrochemical performance of CrNi coating in 3.5% NaCl solution was investigated using an electrochemical workstation.
Findings
The electrochemical corrosion performance of CrNi coating enhances with the increase of Y2O3 mass fraction, and the CrNi–15%Y2O3 coating has the largest polarization resistance and the lowest corrosion current density, which displays the best electrochemical performance among the CrNi–5%Y2O3, –10%Y2O3 and –15%Y2O3 coatings. The protective films are formed with the increase of Y2O3 mass fraction, which inhibits the occurrence of electrochemical corrosion.
Originality/value
The Y2O3 was first added to the CrNi coating to improve its electrochemical corrosion performance, and the influence of Y2O3 on the corrosion resistance of the CrNi coating was discussed by the corrosion model.
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Li Wei and Kong Dejun
This paper aims to analyze the effect of Y2O3 mass fraction on the tribological performance of CrNi coating, which solved the problem of wear resistance on AISI H13 steel.
Abstract
Purpose
This paper aims to analyze the effect of Y2O3 mass fraction on the tribological performance of CrNi coating, which solved the problem of wear resistance on AISI H13 steel.
Design/methodology/approach
Y2O3 reinforced CrNi coatings were fabricated on AISI H13 steel. The microstructure and phases of obtained coatings were analyzed using a super-depth of field microscope and X-ray diffraction, respectively, and the effects of Y2O3 mass fraction on the microstructure and wear resistance were methodically investigated using a wear tester.
Findings
The average coefficients of friction and wear rates of Y2O3 reinforced CrNi coatings decrease with the increase of Y2O3 mass fraction, in which the Y2O3 plays a role of friction reduction and wear resistance. The wear mechanism of Y2O3 reinforced CrNi coating is primary abrasive wear, accompanied by adhesive wear, which is contributed to the grain refinement and dense structure by the Y2O3 addition.
Originality/value
The Y2O3 was added to the CrNi coating by laser cladding, and the effect mechanism of Y2O3 mass fraction on the tribological performance of CrNi coating was established by the wear model.
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Li Jiahong and Kong Dejun
The purpose of this paper is to improve the salt spray corrosion and electrochemical corrosion performances of H13 hot work mould steel, Cr–Ni coatings with the different Cr and…
Abstract
Purpose
The purpose of this paper is to improve the salt spray corrosion and electrochemical corrosion performances of H13 hot work mould steel, Cr–Ni coatings with the different Cr and Ni mass ratios are fabricated using a laser cladding (LC), which provides an experimental basis for the surface modification treatment of H13 steel.
Design/methodology/approach
Cr–Ni coatings with the different Cr and Ni mass ratios were firstly fabricated on H13 hot work mould steel using a laser cladding (LC). The salt spray corrosion (SSC) and electrochemical corrosion performances of Cr–Ni coatings in 3.5 Wt.% NaCl solution were investigated to analyze the corrosion mechanism, and the effect of mass ratios of Cr and Ni on their corrosion mechanism was discussed.
Findings
The laser cladded Cr–Ni coatings with the different Cr and Ni mass ratios are composed of Cr–Ni compounds, which are metallurgically combined with the substrate. The SSC resistance of Cr–Ni coating with the Cr and Ni mass ratios of 24:76 is the highest. The electrochemical corrosion resistance of Cr–Ni coating with the Cr and Ni mass ratio of 24:76 is the best among the three kinds of coatings.
Originality/value
In this study, the corrosion resistance of laser cladded Cr–Ni coatings with the Cr and Ni mass ratios of 17: 83, 20: 80 and 24: 76 was first evaluated using salt spray corrosion (SSC) and electrochemical tests, and the effect of mass ratios of Cr and Ni on their corrosion mechanism was discussed.
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Haichen Zhou, Dejun Zheng, Yongming Li and Junwei Shen
To further provide some insight into mobile library (m-library) applications (apps) user needs and help libraries or app providers improve the service quality, the purpose of this…
Abstract
Purpose
To further provide some insight into mobile library (m-library) applications (apps) user needs and help libraries or app providers improve the service quality, the purpose of this paper is to explore all the types of user improvement needs and to discover which need is the most important based on user results.
Design/methodology/approach
Data were collected from more than 27,000 m-library app users from 16 provinces and autonomous regions in China. Text analysis using latent Dirichlet allocation and Word2Vec was carried out by text preprocessing. Furthermore, a visual presentation was conducted through pyLDAvis and word cloud. Finally, combined with expert opinions, the results were summarized to find the different types of needs.
Findings
There are three different types of needs for improvement: needs of function, needs of technology and needs of experience. These types can be further divided into six subtypes: richness of function, feasibility of function, easiness of technology, stableness of technology, optimization of experience and customization of experience. Besides the richness of function, the feasibility of function has received the most attention from users.
Originality/value
Most studies on m-library user needs have only focused on a method of quantitative research based on questionnaire surveys. This study, however, is the first to apply text mining methods for large-scale user opinion texts, which place more focus on user needs and inspire libraries and app providers to further improve their services.
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This study aims to investigate the influences of Al2O3 mass fraction on the corrosive wear and electrochemical behaviors of FeAl–xAl2O3 coatings.
Abstract
Purpose
This study aims to investigate the influences of Al2O3 mass fraction on the corrosive wear and electrochemical behaviors of FeAl–xAl2O3 coatings.
Design/methodology/approach
FeAl–xAl2O3 coatings were prepared on S355 steel by laser cladding to improve its corrosive wear and electrochemical properties.
Findings
The average coefficients of friction and wear rates of FeAl–xAl2O3 coatings are decreased with the Al2O3 mass fraction, and the Al2O3 plays a positive role in the corrosion wear resistance. Moreover, the charge transfer resistance of FeAl–xAl2O3 coatings is increased with the Al2O3 mass fraction, showing the FeAl–15%Al2O3 coating has the best corrosion resistance. The findings show the corrosion resistance of FeAl–15%Al2O3 coating is the highest among the three kinds of coatings.
Originality/value
Al2O3 was first added into FeAl coatings to further improve its corrosive wear and electrochemical properties by laser cladding.
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Zhao Peng and Kong Dejun
The aim was to investigate the effect of normal load on the tribological performance of laser cladded FeCoCrMoSi amorphous coating, which might choose the appropriate normal load…
Abstract
Purpose
The aim was to investigate the effect of normal load on the tribological performance of laser cladded FeCoCrMoSi amorphous coating, which might choose the appropriate normal load for the friction reduction and wear resistance.
Design/methodology/approach
A FeCoCrMoSi amorphous coating was prepared on 45 steel using laser cladding, and the tribological performance of obtained coating under the different normal loads was investigated using a ball-on-disk tribometer.
Findings
The FeCoCrMoSi amorphous coating is composed of M23C6, Co6Mo6C2 and amorphous phases, where the M23C6 hard phase enhances the coating hardness to increase the wear resistance and the Co6Mo6C2 with the vein shape forms the strong mechanical interlock to play the role of friction reduction. The average coefficients of friction of containing amorphous FeCoCrMoSi coating under the normal loads of 3, 4 and 5 N are 0.68, 0.65 and 0.53, respectively, and the corresponding wear rates are 17.7, 23.9 and 21.9 µm3•N−1•mm−1, respectively, showing that the appropriate normal load is beneficial for improving its friction reduction and wear resistance. The wear mechanism is composed of adhesive wear, abrasive wear and oxidative wear, which is attributed to the high hardness of amorphous coating by the amorphous phase.
Originality/value
The FeCoCrMoSi amorphous coating was first applied for the improvement of 45 steel, and the effect of normal load on its tribological performance was investigated.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2024-0304/
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The purpose of this paper is to investigate the effects of laser power on the electrochemical corrosion performance in 3.5% NaCl, 0.1 M H2SO4 and 0.1 M NaOH solutions, which…
Abstract
Purpose
The purpose of this paper is to investigate the effects of laser power on the electrochemical corrosion performance in 3.5% NaCl, 0.1 M H2SO4 and 0.1 M NaOH solutions, which provided an experimental basis for the application of Al–Ti–Ni amorphous coating in marine environment.
Design/methodology/approach
Amorphous Al–Ti–Ni coatings were fabricated on S355 structural steel by laser thermal spraying (LTS) at different laser powers. The surface and cross-section morphologies, chemical element distribution, phases and crystallization behaviors of obtained coatings were analyzed using a scanning electron microscope, energy-dispersive X-ray spectroscope, X-ray diffraction and differential scanning calorimetry, respectively. The effects of laser power on the electrochemical corrosion performances of Al–Ti–Ni coatings in 3.5% NaCl, 0.1 M H2SO4 and 0.1 M NaOH solutions were investigated using an electrochemical workstation.
Findings
The crystallization temperature of Al–Ti–Ni coatings fabricated at the laser power of 1,300 and 1,700 W is ∼520°C, whereas that fabricated at the laser power of 1,500 W is ∼310°C. The coatings display excellent corrosion resistance in 3.5% NaCl and 0.1 M NaOH solutions, while a faster dissolution rate in 0.1 M H2SO4 solution. The coatings fabricated at the laser power of 1,300 and 1,700 W present the better electrochemical corrosion resistance in 3.5% NaCl and 0.1 M NaOH solutions, whereas that fabricated at the laser power of 1,500 W exhibits the better electrochemical corrosion resistance in 0.1 M H2SO4 solution.
Originality/value
In this work, Al-wire-cored Ti–Ni powder was first on S355 steel with the laser power of 1,300, 1,500 and 1,700 W, and the effects of laser power on the electrochemical corrosion performance in 3.5% NaCl, 0.1 M H2SO4 and 0.1 M NaOH solutions were investigated using an electrochemical workstation.