Surface Modification, Repairing and Forming of Metallic Materials by Additive Manufacturing

A special issue of Coatings (ISSN 2079-6412). This special issue belongs to the section "Surface Characterization, Deposition and Modification".

Deadline for manuscript submissions: 31 January 2025 | Viewed by 8060

Special Issue Editor


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Guest Editor
School of Mechanical Engineering, Dalian Jiaotong University, Dalian 116028, China
Interests: additive manufacturing

Special Issue Information

Dear Colleagues,

With the development of heavy-haul and high-speed trains, the failures of parts in rail traffic must be responded to in a serious and effective manner. In order to prolong the service life of parts, performance strengthening via the creation of coatings on the surface of parts in their development, and the repairing of the damaged parts based on the additive manufacturing (AM) following any failure both play an increasingly important role in rail transit. In addition, with the increasing global attention being devoted to environmental protection and the concept of green development, ensuring parts are lightweight in rail transit has become an important way for the improving of rail transit operation efficiency, energy saving, emission reduction, and the promotion of material technology innovation. However, applying AM technology to rail transit still poses a significant challenge due to the difficulty of precision-property coordinated controlling and the current high demand. Research on the application of AM in rail transit requires continuous efforts.

In this Special Issue, we are accepting manuscripts that report on the recent developments in this area. Research areas may include (but are not limited to) the following: the design, processing, and characterization of coatings, novel approaches of material design and AM processing for rail transit, lightweight design, and the performance of parts in rail transit.

We look forward to receiving your contributions.

Dr. Xinlin Wang
Guest Editor

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Keywords

  • rail transit
  • additive manufacturing
  • coatings
  • repairing
  • lightweight of parts

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Published Papers (10 papers)

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Research

21 pages, 15853 KiB  
Article
Numerical Investigation of Film Formation Characteristics and Mechanisms through Airless Spraying on Spherical Surfaces
by Zhaojie Wu, Chuanshuo Wang, Guichun Yang, Shiming Chen, Jimiao Duan and Yan Chen
Coatings 2024, 14(10), 1299; https://doi.org/10.3390/coatings14101299 - 11 Oct 2024
Viewed by 409
Abstract
This paper focuses on key engineering issues, particularly the overall turbulent transport of paint spray and coating film distribution characteristics, in the process of airless spraying film formation. By deeply considering the geometric features of spherical surfaces and their impact on the near-wall [...] Read more.
This paper focuses on key engineering issues, particularly the overall turbulent transport of paint spray and coating film distribution characteristics, in the process of airless spraying film formation. By deeply considering the geometric features of spherical surfaces and their impact on the near-wall region of the flow field, an airless spraying film formation model consisting of the Eulerian multiphase model, the realizable k–ε turbulence model, and the Eulerian Wall Film model was established. Through numerical simulations of static spraying on the inner and outer walls of spherical surfaces with different radii, the influence of geometric features on the spray flow field and film formation characteristics on spherical surfaces was investigated. Subsequently, based on numerical simulations of dynamic spraying on different nozzle trajectories, the film formation characteristics were analyzed, and the optimal spray trajectory planning method was determined. Additionally, this study examined the coating distribution characteristics during dynamic spraying on spherical surfaces with varying geometric dimensions. Finally, a kind of chlorinated rubber anti-corrosion primer was chosen to carry out spraying experiments, which validated that the airless spray coating model and the corresponding numerical simulation methods established in this paper were reasonable and feasible for investigating the film formation characteristics on spherical surfaces. This work is expected to further promote the application of airless spray techniques in machinery, automotive, shipbuilding, and aviation industries. Full article
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13 pages, 8226 KiB  
Article
Optimal Design of Multilevel Composite Lubrication Structures on Sliding Guide Rail Surfaces
by Hong Bao, Mengjie Hao, Yuchen Du and Yuzhe Chen
Coatings 2024, 14(10), 1286; https://doi.org/10.3390/coatings14101286 - 9 Oct 2024
Viewed by 407
Abstract
To optimize the crawling phenomenon of slides under circumstances of low speed and a heavy load, a composite lubrication structure is adopted to alleviate the crawling phenomenon. The response surface optimal-design method establishes a quadratic mathematical model for multistage composite lubrication structure parameters, [...] Read more.
To optimize the crawling phenomenon of slides under circumstances of low speed and a heavy load, a composite lubrication structure is adopted to alleviate the crawling phenomenon. The response surface optimal-design method establishes a quadratic mathematical model for multistage composite lubrication structure parameters, including crawling time and average friction coefficient. The optimal combination parameters of multistage composite lubrication structures have been determined. The optimal ratio of lubricating oil to molybdenum disulfide (MoS2) has been identified, and a composite lubrication structure has been proposed to enhance the crawling phenomenon and friction performance of sliding guide rails under medium-speed and medium-load conditions. These research outcomes indicate that when low speed and a heavy load are present, the crawling time and friction coefficient initially diminish and subsequently augment as the width, spacing, and cycle length of the sinusoidal texture and the diameter of the hexagonal pit expand. The optimum configuration of multistage composite lubrication structures is as follows: The width of the sine-wave texture b amounts to 0.15 mm, the cycle length e is 2 mm, the spacing c is 1.5 mm, and the diameter of the hexagonal pit d is 0.2 mm. When the mass ratio of guide oil to MoS2 is 2:1, it exhibits supreme crawling resistance and antifriction attributes. In circumstances involving a medium load and speed, multistage composite lubrication structures manifest pre-eminent friction performance. These data can steer the design of multistage composite lubrication structures on the surface of slide rails. Full article
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15 pages, 5973 KiB  
Article
Systematic First-Principles Investigations of the Nucleation, Growth, and Surface Properties of Al11RE3 Second-Phase Particles in Al-Based Alloys
by Wei Yin, Yuming Liu, Lan Lin, Yiru Wang, Leyi Chen, Zhaoting Li, Honghu Peng, Touwen Fan, Yuanzhi Wu, Yuanxiang Deng, Xiong Liu and Dongchu Chen
Coatings 2024, 14(8), 983; https://doi.org/10.3390/coatings14080983 - 4 Aug 2024
Cited by 1 | Viewed by 734
Abstract
At room temperature, Al alloys have excellent mechanical properties and are widely used in automotive, electronics, aerospace and other fields, but it is difficult to maintain this advantage in the middle and high temperature ranges. To address this issue, second-phase Al11RE [...] Read more.
At room temperature, Al alloys have excellent mechanical properties and are widely used in automotive, electronics, aerospace and other fields, but it is difficult to maintain this advantage in the middle and high temperature ranges. To address this issue, second-phase Al11RE3 (RE represents rare earth element) was introduced into a Al-Mg-RE alloy as its primary constituent. By incorporating RE elements as additives, this material exhibits exceptional mechanical and thermal properties at elevated temperatures. Based on first principles and quasi-harmonic approximation (QHA), the nucleation growth mechanism and surface properties of second-phase Al11RE3 were studied in this paper. The interfacial energy γα/β, strain energy ΔECS and chemical driving force ΔGV of Al11RE3 were obtained. Models1, 4, and 6 have better properties of para-site connections than inter-site connections. It is found that the resistances of particle nucleation, interface energy γα/β and strain energy ΔECS, first increase and then decrease with increased atomic number REs, but they are much smaller than the chemical driving force ΔGV. A reduced chemical driving force and a diminished nucleation radius R* are more favorable for the process of nucleation. The addition of Sc is the most unfavorable for nucleation, and La has the strongest nucleating ability, which gradually decreases as the atomic number of the lanthanide element increases. The nucleation ability of the Al11RE3 phase decreases with increasing temperature, which is consistent with the experiments. The nucleation radius R* also increases with increasing temperature, indicating that the nucleation ability decreases as the atomic number of the lanthanide elements increases. Since the smaller the nucleation radius R* the easier the nucleation, compared with model4 and 6, model1 has a smaller nucleation radius R* and the smallest increment. Thus, model1 is more prominent in the nucleation mechanism. In the particle growth study, the smaller the diffusion activation energy Q, the faster the diffusion rate in the Al matrix, and hence the higher the coiling rate, which promotes the growth of second-phase particles. The diffusion activation energy Q decreases sequentially from La to Ce and then increases with atomic number. The coarsening rate KLSW of the Al11RE3 phase in models1, 4, and 6 increased with increasing temperature, which promoted the growth of particles. This paper is intended to provide a solid theoretical basis for the production and application of aluminum alloy at high temperatures. Full article
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18 pages, 10235 KiB  
Article
Study on the Formation Mechanism of Serrated Chips in the Cutting Process of Powder Metallurgy Superalloys Based on a Modified J–C Constitutive Relation Simulation Model
by Xiaoping Ren, Chen Ling, Xuepeng Wang, Yinghao Li, Zhanqiang Liu and Bing Wang
Coatings 2024, 14(8), 933; https://doi.org/10.3390/coatings14080933 - 25 Jul 2024
Viewed by 702
Abstract
Powder metallurgy superalloys are attracting great attention due to their unique performance advantages, such as good oxidation resistance, corrosion resistance, excellent tensile behavior, durability, fatigue properties, and long-term tissue stability. Therefore, powder superalloys show strong vitality in the field of advanced aerospace engines. [...] Read more.
Powder metallurgy superalloys are attracting great attention due to their unique performance advantages, such as good oxidation resistance, corrosion resistance, excellent tensile behavior, durability, fatigue properties, and long-term tissue stability. Therefore, powder superalloys show strong vitality in the field of advanced aerospace engines. However, the cutting force is large, and the serrated chips lead to poor machinability in the cutting process. The influence of dynamic recrystallization softening on serrated chips in the cutting process cannot be ignored. In this paper, the formation mechanism of serrated chips in the FGH96 cutting process is studied considering the influence of dynamic recrystallization softening. Firstly, based on the J–C constitutive relation modified by the recrystallization stress softening established previously, a finite element simulation model of the right-angle cutting of FGH96 is established. According to the results of the simulation model, the variation law of the thermal mechanical loading field in the formation process of serrated chips is quantitatively characterized. The validity of the simulation model is verified by comparison with the cutting force, chip morphology, and strain rate obtained from the experiment. Simulation results show that, in the formation process of serrated chips, the temperature field, strain field, and strain rate field in the first deformation zone show similar distribution characteristics to the shear band distribution, and with the formation of serrated chips, their values gradually increase. On this basis, the formation mechanism of serrated chips is revealed, which is the stage of serrated chip initiation, the stage of generating 50% serrated chips, the stage of generating 75% serrated chips, and the stage of serrated chip formation. Full article
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21 pages, 16949 KiB  
Article
Research on Film Formation Characteristics by Spraying on Unidiameter Vertical Interpenetrating Cylindrical Surfaces
by Zhaojie Wu, Yan Chen, Shiming Chen, Jimiao Duan and Jiang Li
Coatings 2024, 14(7), 847; https://doi.org/10.3390/coatings14070847 - 5 Jul 2024
Viewed by 664
Abstract
Unidiameter Vertical Interpenetrating Cylindrical Surfaces (UVICS, also called T-pipe surfaces) are a type of typical complex surface that exists in facilities or equipment such as oil storage tanks and industrial pipelines. The shape and surface characteristics of a component undergoing spraying will have [...] Read more.
Unidiameter Vertical Interpenetrating Cylindrical Surfaces (UVICS, also called T-pipe surfaces) are a type of typical complex surface that exists in facilities or equipment such as oil storage tanks and industrial pipelines. The shape and surface characteristics of a component undergoing spraying will have a significant impact on the spray flow field and the resulting coating film. In order to optimize the coating effects of complex surfaces, the Euler-Euler approach was utilized to model a spray film formation process that encompasses both a spray flow field model and a wall adhesion model. Subsequently, the influence of the geometric features, geometric dimensions, lateral air pressure of the spray gun, and spraying distance on the coating film characteristics of this kind of surface were systematically investigated. It is determined that the film thickness uniformity could be enhanced by decreasing the dimensions of the workpiece or increasing the lateral air pressure and spraying distance in an appropriate manner when spraying at the location with the most complex geometric features of UVICS. Furthermore, the optimal parameters under varying spraying conditions were identified. The experiments validated the accuracy of the numerical simulation results and demonstrated the feasibility of this simulation model. The study is of significant value in addressing the challenges associated with film formation during spraying on complex surfaces, developing a comprehensive theoretical framework for air spraying, and expanding the scope of applications for automatic spraying technology. Full article
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9 pages, 5195 KiB  
Article
Advancing Atomic Force Microscopy: Design of Innovative IP-Dip Polymer Cantilevers and Their Exemplary Fabrication via 3D Laser Microprinting
by Peter Gaso, Daniel Jandura, Sergii Bulatov, Dusan Pudis and Matej Goraus
Coatings 2024, 14(7), 841; https://doi.org/10.3390/coatings14070841 - 4 Jul 2024
Viewed by 913
Abstract
This paper presents the design and fabrication of new types of polymer-based cantilevers for atomic force microscopy. The design and fabrication are aimed at the capability of 3D laser microprinting technology based on two-photon polymerization on a standard silicon substrate. IP-Dip commercial material [...] Read more.
This paper presents the design and fabrication of new types of polymer-based cantilevers for atomic force microscopy. The design and fabrication are aimed at the capability of 3D laser microprinting technology based on two-photon polymerization on a standard silicon substrate. IP-Dip commercial material from the Nanoscribe company was used for the fabrication of the designed cantilevers. The fabricated microprinted cantilevers facilitate precise manipulation at the nanoscopic scale, which is essential for studying nanomaterials’ mechanical, electrical, and optical properties. The cantilevers’ flexibility allows for the integration of functional elements such as piezoelectric layers and optical fibers, enabling combined measurements of multiple physical parameters. Various cantilever geometries, including rectangular and V-shaped, are examined, and their resonance frequencies are calculated. The experimental process involves preparing the cantilevers on a silicon substrate and coating them with aluminum for enhanced reflectivity and conductivity. Scanning electron microscope analysis documents the precise form of prepared polymer cantilevers. The functionality of the probes is validated by scanning a step-height standard grating. This study demonstrates the versatility and precision of the fabricated cantilevers, showcasing their potential for large-area scans, living cell investigation, and diverse nanotechnology applications. Full article
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15 pages, 10942 KiB  
Article
Calculation of Stress Intensity Factor for Annular Double Cracks on Inner Surface of Pipeline
by Jintai Cui, Huifang Li, Zhiwei Wu and Caifu Qian
Coatings 2024, 14(6), 744; https://doi.org/10.3390/coatings14060744 - 12 Jun 2024
Viewed by 636
Abstract
Cracks in engineered pipelines often appear in the form of multiple cracks or crack clusters with interactions between them. It is important to study the interaction between cracks if the pipeline crack cluster is to be evaluated in terms of equivalence and safety [...] Read more.
Cracks in engineered pipelines often appear in the form of multiple cracks or crack clusters with interactions between them. It is important to study the interaction between cracks if the pipeline crack cluster is to be evaluated in terms of equivalence and safety assessment. In this paper, based on FRANC3D crack analysis software, the interaction between circumferential parallel double cracks on the inner surface of pipelines was investigated, the factors affecting the interaction were examined, and the empirical equations for calculating the stress intensity factor (SIF) of double cracks was proposed. The results show that if there is no bias between the double cracks, the crack leading edge is shielded, but if there is offset between the double cracks, the crack leading edge is subjected to different interactions at different locations. The distal end of the cracks is generally strengthened, while the proximal end of the cracks is probably more shielded. The interaction effects between cracks are dependent on their relative positions rather than the pipe size or concerned crack size. According to the numerical simulation, boundaries for shielding or enhancing interactions were obtained, and the stress intensity factor calculation equations were fitted. Full article
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22 pages, 26927 KiB  
Article
Experimental Study on the Process of Submerged Arc Welding for Nickel-Based WC Flux-Cored Wire on Descaling Roll
by Chang Li, Lei Feng, Xing Han, Fenghua Luo and Han Sun
Coatings 2024, 14(6), 734; https://doi.org/10.3390/coatings14060734 - 8 Jun 2024
Viewed by 1185
Abstract
Descaling roll is a key component used to remove iron oxide on billet surface in hot rolling production lines, and its surface properties have a significant effect on the quality of hot rolling products. The descaling roll is in bad service condition and [...] Read more.
Descaling roll is a key component used to remove iron oxide on billet surface in hot rolling production lines, and its surface properties have a significant effect on the quality of hot rolling products. The descaling roll is in bad service condition and subjected to the dynamic impact caused by high-pressure water erosion and high temperature billet descaling process for a long time. Under the action of high temperature, strong wear, multi-cycle heat, force, flow and multi-field strong coupling, the surface is prone to wear and corrosion failure, which affects the continuous rolling production. Submerged arc welding provides an effective way to repair and strengthen the descaling roll surface. The content of WC hard phase has a significant effect on welding quality. At the same time, direct submerged arc welding of Ni based WC wire on the descaling roll surface is easy to cause cracks, and a gradient synergistic strengthening effect can be formed by setting the transition bottom layer in welding. At present, there is a lack of experiments related to the preparation of flux-cored wire with different contents and the overlaying for the bottom submerged arc welding. Relevant studies are urgently needed to further reveal the welding process mechanism to provide significant theoretical support for the preparation of wire materials and the improvement of welding quality. In this paper, 30% and 60% WC flux-cored wires were prepared by employing Ni-Cr-B-Si alloy powder as the base powder, and submerged arc welding tests were conducted on the descaling roll, preparing three welding layers, namely 70% NiCrBSi + 30% WC without the bottom layer, 70% NiCrBSi + 30% WC with the bottom layer, and 40% NiCrBSi + 60% WC with the bottom layer. The properties of the welding layer were evaluated by SEM, XRD, EDS, hardness, friction and wear, corrosion and impact experiments. The results show that the WC hard phase added in the filler metal has dissolved and formed a new phase with other elements in the melting pool. The surfacing layer mainly contains Fe-Ni, Cr-C, Fe3Si, Ni3C and other phases. The surfacing layer prepared by a different amount of WC flux-cored wire and the surfacing layer with or without the bottom layer have great differences in microstructure and properties. This study lays a significant theoretical foundation for optimizing the submerged arc welding process and preparing welding materials for the descaling roll and has significant practical significance and application value. Full article
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19 pages, 9521 KiB  
Article
Experimental Study on Preparation of Tungsten-Carbide-Particle-Reinforced Nickel-Based Alloy Plasma Surfacing Layer on Descaling Roller Surface
by Lei Feng, Chang Li, Xing Han, Fenghua Luo and Han Sun
Coatings 2024, 14(6), 729; https://doi.org/10.3390/coatings14060729 - 6 Jun 2024
Viewed by 1039
Abstract
The descaling roller is a significant component in steel rolling production. Under harsh service conditions, the descaling roller is subjected to the dynamic impact caused by high-pressure water erosion and a high-temperature billet descaling process for a long time. Under the harsh conditions [...] Read more.
The descaling roller is a significant component in steel rolling production. Under harsh service conditions, the descaling roller is subjected to the dynamic impact caused by high-pressure water erosion and a high-temperature billet descaling process for a long time. Under the harsh conditions of high temperature, strong wear, multi-cycle heat, force, flow, and multi-field strong coupling, the roller surface is prone to wear and corrosion failure, which affects the production cost and efficiency. Through plasma surfacing technology, a high-performance coating can be applied on the conventional metal surface to effectively improve its surface properties. It is important to carry out experimental research on the surface plasma surfacing of the descaling roller to prolong product life, improve product quality, and save cost. At present, the research on the 42CrMo scaler matrix plasma surfacing of nickel-based alloys with different WC contents is still lacking. In this paper, 70%NiCrBSi+30%WC powder and 40%NiCrBSi+60%WC powder were used as surfacing materials; plasma surfacing experiments were carried out on the 42CrMo matrix; and SEM, XRD, microhardness, friction and wear, and corrosion tests were carried out on the surfacing layer to evaluate the feasibility of preparing an ultra-high-hardness WC-particle-reinforced nickel-based alloy plasma surfacing layer on the descaling roller surface and to explore the WC hard phase dissolution behavior and complex secondary phase formation mechanism. The results show that γ(Fe/Ni), Fe-Ni, FeSi, Fe3C, and M7C3 are the main phases in the Ni/WC plasma surfacing layer. The diffusion and precipitation of elements occur in the molten pool, and complex secondary phases are formed in the surfacing layer. Compared with the 70%NiCrBSi+30%WC surfacing layer, the WC deposition phenomenon of the 40%NiCrBSi+60%WC surfacing layer has been significantly improved and has better hardness, wear resistance, and corrosion resistance. Based on the welding test, the correlation law between powder formulation, welding structure, and surfacing layer properties was revealed in this study, which lays a theoretical foundation for the preparation of high-performance coating on the descaling roller surface and has significant engineering application value and practical significance. Full article
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14 pages, 15648 KiB  
Article
Effects of ZrW2O8 Content on the Microstructures and Properties of Composite Coatings Produced by Laser Cladding
by Pengxian Zhang, Chang Liu and Yibin Pang
Coatings 2024, 14(5), 649; https://doi.org/10.3390/coatings14050649 - 20 May 2024
Viewed by 757
Abstract
Addressing the issue of cracking in laser-cladding Ni-based composite coatings with WC particles, this study explored an approach to fabricating a crack-free coating by incorporating ZrW2O8 powder. The influence of varying ZrW2O8 contents on the crack susceptibility, [...] Read more.
Addressing the issue of cracking in laser-cladding Ni-based composite coatings with WC particles, this study explored an approach to fabricating a crack-free coating by incorporating ZrW2O8 powder. The influence of varying ZrW2O8 contents on the crack susceptibility, microstructure, microhardness, wear resistance, and corrosion resistance of Ni60/WC composite coatings was systematically examined. The findings indicate that the ZrW2O8 content significantly impacts the microstructure and functional properties of the coating. Furthermore, it is suggested that the main contributors to preventing crack formation and diffusion are believed to be the pressure interaction caused by the negative expansion effect of ZrW2O8, as well as the in situ phase transition and diffusion toughening of ZrO2 during its decomposition process. The feasibility of achieving crack selfhealing through the addition of specific amounts of ZrW2O8 powder has been conclusively demonstrated. Full article
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