Poor Surface Research Articles

Analysis of Soil–Straw Movement Behavior in Saline–Alkali Soil Under Dual-Axis Rotary Tillage Based on EDEM

The layered soil crushing rotary tillage machine with L-shaped reclamation rotary blades and rotary-reclamation rotary blades combination was designed to deal with the problems of a low soil fragmentation rate, low straw mulching rate, and poor surface leveling after plowing in the traditional rotary tiller tillage mode in the coastal saline land of the Yellow River Delta. A dual active layered soil fragmentation tillage mode was proposed, and the key structural parameters, blade axis arrangement, and spatial layout of L-shaped reclamation rotary blades and rotary-reclamation rotary blades were determined based on the sliding cutting principle analysis. A discrete element model of soil straw tillage component aggregates suitable for coastal saline alkali land was constructed using EDEM, and the influence of L-shaped reclamation rotary blades and rotary-reclamation rotary blades on the soil tillage layer displacement performance and straw burial performance of saline alkali land was comprehensively analyzed from a microscopic perspective. Taking the rotation speed of the L-shaped reclamation rotary blades, the rotation speed of the rotary-reclamation rotary blades, and the forward speed as experimental factors, and using soil fragmentation rate and straw burial rate as evaluation indicators for experimental optimization analysis, the optimal parameters were obtained: the rotation speed of the L-shaped reclamation rotary blades was 295.04 r/min, the rotation speed of the rotary-reclamation rotary blades was 359.06 r/min, and the forward speed was 3.12 km/h. At this time, the theoretical soil fragmentation rate of saline alkali land was 94.67%, and the straw burial rate was 93.56%. Field experiments have shown that the average soil fragmentation rate of the L-shaped reclamation rotary blades and rotary-reclamation rotary blades combined layered soil crushing rotary tiller after cultivation is 94.37%, the straw burial rate is 95.68%, the surface flatness is 25.82 mm, and the stability of the tillage depth is 95.64%. The machine has shown increased performance in comparison to traditional single axis rotary tillers, meeting the needs of crop bed preparation in saline alkali land.

Study on Polishing Technologies for Additive Manufacturing Parts

Additive manufacturing has a good application prospect in aerospace, medical implantation and other fields, but the molding surface quality is poor, without post processing can not meet the requirements of high service, polishing processing is a key link in the high-performance metal additive manufacturing technology chain. This paper summarizes the characteristics of the ladder effect, the high roughness of the forming surface. In recent years, additive manufacturing technology, also known as 3D printing, has been highly valued by aviation enterprises for its unique advantage in rapid prototyping, particularly for complex metal parts. However, due to the layer-by-layer growing process of 3D printing, the built parts often have poor surface roughness and are not suitable for practical use without post-treatment. Based on this foundation, the primary focus of research in the field of additive manufacturing for metal parts polishing includes electrochemical, laser, and abrasive flow polishing technologies. The progress in these areas is examined with consideration given to various manufacturing processes, different types of metal powder materials, and diverse structures (such as porous structure and high aspect flow channels) found in additive manufacturing samples. This review summarizes the research findings related to surface roughness, material removal, surface residual stress, profile accuracy retention, and other technical indicators associated with the polishing process for additive manufacturing metal parts. Finally, the paper discusses potential future developments in polishing technology for 3D printed metal parts.

Influence of Laser‐Assisted Cutting on the Surface Integrity and Fatigue Life of FeCoCrNiAl0.6 High‐Entropy Alloy

ABSTRACTThis study explores the application of laser‐assisted cutting (LAC) in FeCoCrNiAl0.6 high‐entropy alloys to address traditional machining challenges and poor surface quality. It systematically analyzes the effects of laser power, scan speed, and spot diameter on surface integrity and fatigue life. Using Abaqus/FE‐SAFE simulations and LAC experiments, differences in surface quality and fatigue cycles under various laser parameters are observed. Results show that increasing the spot radius reduces heat accumulation and center temperature. A 1 mm radius yields a center temperature 5.58 times higher than a 7 mm radius and achieves a residual compressive stress of 412 MPa, which decreases to 198 MPa (51.9% reduction) at 7 mm. Larger laser power increases stress and fatigue life positively, while higher scan speeds reduce stress. Fatigue cycles drop by 82.9% as the spot radius increases from 1 to 7 mm, while 25 W power extends fatigue life 4.26 times compared to 10 W.

Enhancing corrosion resistance of Nd-Fe-B magnets with amorphization Ni-P coatings

Nd-Fe-B permanent magnets, due to the unique phase structure, demand exceptional corrosion resistance. Electrodeposited nickel-phosphorus (Ni-P) coatings are recognized for their superior anti-corrosion performance, but the performance of electrodeposited Ni-P coatings with different crystallinity varies considerably from process to process. In this study, we propose a strategy to grow Ni-P coatings that exhibit varying crystallographic orientations and degrees of crystallinity. Meanwhile, the differences in structure, morphology, corrosion resistance, and mechanical properties between crystalline and amorphous Ni-P coatings were systematically investigated. The results show that the crystalline Ni-P alloy coating predominantly forms on the Ni(111) crystal plane, with poor surface topographic flatness. In contrast, the amorphous Ni-P coating demonstrates better surface topographic flatness. The crystalline Ni-P alloy coating exhibits a corrosion potential of −0.63 V, a corrosion current density of 5.6 × 10−7 A cm−2, and a hardness of 583HV. In comparison, the completely amorphous Ni-P alloy coating shows an improved corrosion potential of −0.38 V, an exceedingly low corrosion current density of 9.5 × 10−10 A cm−2, and an increased hardness of 622HV.

TENet: Attention-Frequency Edge-Enhanced 3D Texture Enhancement Network

Oblique photogrammetry imagery often suffers from uneven resolution and blurred details, leading to poor surface texture quality in 3D reconstructions, particularly for building facades. To address these challenges, we propose a novel Attention-Frequency Edge-Enhanced 3D Texture Enhancement Network (TENet) and introduce a comprehensive 3D texture enhancement pipeline. This pipeline applies 2D texture super-resolution techniques to 3D models for fine-grained texture restoration, enhancing the surface texture quality. TENet leverages attention mechanisms and frequency-domain techniques to improve texture sharpness and edge accuracy. Our approach includes a Region-Resolution Adaptive Enhancement Module (RAEM) and a Frequency-Domain Edge Enhancement Mechanism (FDEEM) to enhance local details and restore critical edge features. The experimental results demonstrate that TENet outperforms existing methods, significantly improving texture quality and 3D reconstruction performance. Ablation studies confirmed the effectiveness of each component in enhancing 3D texture reconstruction. The network is validated for real-world applications, showing its ability to significantly reduce edge artifacts and restore clear, accurate textures in real-world 3D surface models.

Laser Surface Texturing in Single-Point Incremental Sheet Forming

Abstract Single-point incremental sheet forming (SPIF) offers high flexibility, cost-effectiveness, mass customization, ease of setup, and scalability. However, the process can result in poor surface characteristics, making it important to control them, especially for applications requiring enhanced wettability. To overcome this challenge, the present study introduces a novel technique that uses laser surface texturing (LST) to create micropatterns on the SPIF forming tool and replicate on the planar surface of workpiece. After SPIF process on the opposite side of the workpiece, the replicated micropatterns are maintained without significant effect to the laser textures and keep the surface's wettability. The 3D surface topography of the imprinted micropatterns was characterized. Additionally, a sessile drop test was performed to assess the wettability of the surface both before and after the deformation process. The results showed that a functionalized micropatterned surface can be achieved using the proposed technique without affecting the geometric accuracy. No cracks were observed on the workpiece surface, but during the SPIF process, deformation stretched the imprinted microvalleys, leading to a slight decrease in hydrophobicity compared to the original LST surface.

Titanium Dioxide and Photocatalytic CO2 Reduction: A Detailed Review of the Current Status and Future Prospects

A significant amount of carbon dioxide is released into the atmosphere as a result of the extensive usage of fossil fuels. The photocatalytic reduction and conversion of CO2 under visible light into alternative renewable solar fuels or other oxygenated products (methane, formaldehyde, methanol, and formic acid) are practical and efficient methods for reducing atmospheric carbon pollution. Functional materials containing titanium dioxide (TiO2) have attracted significant interest for the photocatalytic reduction of CO2. In this direction, many studies have been conducted in recent years, especially on solar energy harvesting and the charge separation, adsorption, activation, and reduction of CO2 on enhanced TiO2. Recent studies have shown that brookite TiO2 (BT) was the most active photocatalyst, followed by rutile and anatase. Therefore, this study aims to review in detail the recent advances in the development of selective and active catalysts for photocatalytic CO2 reduction using titanium dioxide with a brookite structure. This review evaluates the most common methods for obtaining BT. It discusses various engineered strategies, including doping with metallic or non-metallic heteroatoms, addition of a co-catalyst, formation of heterojunctions, and other algorithms to improve the CO2 reduction mechanism. The influence of another phase and crystal facets on the photocatalytic CO2 reduction reaction are discussed in detail. The problems associated with BT-based photocatalysts, namely, their modest visible-light absorption, slow interfacial charge separation, and poor surface catalytic dynamics, are further discussed, along with possible solutions. To stimulate additional research in this field, the difficulties and potential advantages of photocatalytic CO2 conversion methods are discussed.

AUTOMATIC DETECTION AND NOTIFICATION OF POTHOLES AND HUMPS ON ROADS TO AID DRIVERS

The Indian subcontinent is the world's second most populous Country and one of its fastest developing economically. Backwardness of roads is also one of the problems in the region. Roads are now the dominant form of transportation in India. In fact, it accounts for about 90 percent of the country's total passenger transport and about 65 percent of the country's total freight transport. Most of the roads in India are narrow and congested with poor surface quality and their maintenance needs are not satisfactorily met. Most of the rural non-tarred roads are in a shabby condition. Most of the roads either become muddy tracks in the rains or dusty tracks during the summer months. Indeed, in India, there are roads built with automatic barriers which control the traffic and flow at ramp sites. It would thus be highly essential to estimate how quickly a ramp could be deployed from an operational standpoint as part of the overall procedure of traffic management. All of these facts therefore highlight that there is different relevant material available on the general nature of undulatio and undulation detection of ramps in India. If the aforementioned are to be operated successfully and efficiently, then necessarily, the target has to be first identified successfully. It is done through filtering interal models with a confidence level in reducing accidents by taking into consideration the aspect of humps and potholes within the Indian landscape. Constant movement and high impact on structures cause depression stressing material reinforcement, ultimately leading to the formation of potholes. Key Words: Road infrastructure, Transportation, Potholes, Humps, Traffic management, Undulation detection, Rural roads, Maintenance.

Application of biomass carbon dots in food packaging.

Since its discovery, carbon quantum dots (CDs) have been widely applied in cell imaging, drug delivery, biosensing, and photocatalysis due to their excellent water solubility, chemical stability, fluorescence stability biocompatibility, low toxicity, and preparation cost. However, the low fluorescence yield and poor surface structure limit the application of CDs. Heteroatom doping is considered an ideal method to improve CDs' optical and electrical properties. From this perspective, eco-friendly biomass and its derivatives are perfect carbon precursors for CDs because they contain the heteroatoms needed to modify CDs, and their complex chemical composition gives CDs a wide variety of surface functional groups. Besides, converting biomass waste into high-value-added CDs is also an innovation in biomass waste treatment. Therefore, this paper focuses on the carbon precursors of biomass CDs. At the same time, food packaging occupies an essential position in the industry, and fluorescent CDs with good fluorescence properties, high chemical stability, and good photobleaching properties have great application potential in packaging innovation techniques that have emerged in recent years, but relevant reports are scarce and scattered. Considering that the surface morphology, chemical structure, and optical and electrical properties of biomass CDs are primarily affected by the carbon precursors' chemical structure and preparation method, this paper also focuses on the synthesis method of biomass CDs and its application in anti-counterfeiting packaging, intelligent packaging, antioxidant packaging, and antibacterial packaging.

Simultaneous enhancement of build rate and microstructure in SS316L additive manufacturing through in-situ laser remelting

The build quality in Laser-Directed Energy Deposition (L-DED) is crucial for industrial production but is often compromised at higher build rates. Higher deposition rates in L-DED typically lead to poor surface finish, high porosity, and solute segregation at grain boundaries. This study investigates in-situ laser remelting with positive defocus to enable a substantially higher deposition rate, i.e., 25 g/min compared to the preferred 7 g/min, in building SS316L components using the powder-based L-DED technique while maintaining the desired build quality. It is shown that laser remelting significantly improves surface finish, reduces porosity by up to 83%, increases microhardness by up to 34%, and eliminates solute segregation compared to the as-deposited case. The effect of specific laser remelting parameters and underlying mechanisms are further investigated via specially designed experiments. The results indicate that employing the highest linear energy density through maximum laser power (2000 W) and minimum scan speed (400 mm/min) yields minimum porosity. On the other hand, employing the lowest linear energy density through minimum laser power (500 W) and maximum scan speed (1000 mm/min) yields the highest microhardness due to grain refinement. An analytical model is utilized to provide insights into the process-structure–property relationship based on experimental measurements of cooling rate, grain size, and microhardness. In conclusion, this research demonstrates the potential of in-situ laser remelting to significantly enhance both build rate and quality in L-DED, offering a promising approach for large-scale part production through periodic laser melting during deposition.

Application of electrical resistivity tomography for groundwater evaluation in Yirgacheffe Town and its environs, Main Ethiopian Rift

Exploring groundwater is crucial in areas with poor surface water quality, such as Yirgacheffe Town and its surroundings. This study aims to assess aquifer materials and groundwater potential using Electrical Resistivity Tomography (ERT) in the region,within the Main Ethiopian Rift. Four electrical resistivity profiles were gathered using a Wenner array with a WDA-1 digital resistivity and induced polarization meter from Chongqing, China. Each profile extended 236 m with 4-m electrode spacing. Data were analyzed and inverted with Res2DinV software and validated against lithological logs. The ERT inversion revealed three subsurface geoelectric layers: (1) massive rhyolite ignimbrite and basalt (>2000 Ωm); (2) weathered rhyolite ignimbrite and basalt (200–2000 Ωm); and (3) topsoil (4–200 Ωm). These results are key for effective water resource management and highlight ERT's utility in similar geological settings.

A review of photoelectrochemical water oxidation using hematite photoanode

Background: The sun, as an abundant and renewable energy source, provides a sustainable alternative to fossil fuels, which contribute significantly to CO₂ emissions and global warming. With CO₂ emissions surpassing 35 billion tons in 2023, the need for clean energy solutions has become increasingly urgent. Solar energy utilization includes photoelectrochemical (PEC) water splitting, where hematite is widely recognized as an efficient photoanode material due to its availability, stability, and favorable band gap for visible light absorption. However, hematite faces challenges such as poor conductivity, surface recombination, and slow oxygen evolution reaction (OER) kinetics, which limit its performance. Methods: This review examines various strategies to enhance hematite photoanode performance for PEC water splitting. The study explores three key approaches: (1) using three-dimensional conductive substrates with high surface area to facilitate heterojunction formation, (2) doping with tetravalent metal ions (e.g., Ti⁴⁺) to improve conductivity and charge carrier density, and (3) integrating Bi₂WO₆ with hematite to enhance charge separation and photoelectrochemical efficiency. The hydrothermal method was applied for hematite fabrication due to its feasibility, cost-effectiveness, and scalability. Findings: The analysis highlights the effectiveness of each strategy in overcoming hematite’s inherent limitations. The use of 3D conductive substrates improves electron transport and surface reaction sites, while Ti⁴⁺ doping enhances charge carrier density and conductivity. Conclusion: Hematite remains a promising photoanode material for PEC water splitting, but its limitations must be addressed to maximize efficiency. The combination of 3D conductive substrates, metal ion doping, and Bi₂WO₆ integration has shown potential in improving hematite’s photoelectrochemical performance. Novelty/Originality of this article: This review provides a comprehensive analysis of hematite performance enhancement strategies, focusing on the synergistic effects of 3D conductive substrates, Ti⁴⁺ doping, and Bi₂WO₆ integration.

An Investigation on the Laser Abrasive Jet Machining of glass using Taguchi L27 arrays

Abstract: Nowadays, it might be challenging to machine materials that are difficult to cut. The main issues with machinability are high cutting powers, poor surface quality, and short tool lives. Traditional machining techniques have been shown to be less efficient and time- consuming. Nowadays, it might be challenging to machine materials that are difficult to cut. Nowadays, researchers are choosing hybrid machining techniques to solve these issues. The laser-assisted machining approach has drawn attention recently among other techniques. The cutting of difficult-to-cut materials with the aid of lasers can improve the machinability of those materials. Heat assistance is provided by a low power CO2 laser, and a HYBRID non- conventional machining technique is created by combining CO2 laser machining with an abrasive jet approach. In the aforementioned study, two unconventional machining techniques are used to evaluate the process variables, performance traits for a better material removal rate, and surface roughness. This work summarises the machining process for the machining of challenging materials using laser assistance.

Revealing formation mechanism of end of process depression in laser powder bed fusion by multi-physics meso-scale simulation

ABSTRACT Unintended end-of-process depression (EOPD) commonly occurs in laser powder bed fusion (LPBF), leading to poor surface quality and lower fatigue strength, especially for many implants. In this study, a high-fidelity multi-physics meso-scale simulation model is developed to uncover the forming mechanism of this defect. A defect-process map of the EOPD phenomenon is obtained using this simulation model. It is found that the EOPD formation mechanisms are different under distinct regions of process parameters. At low scanning speeds in keyhole mode, the long-lasting recoil pressure and the large temperature gradient easily induce EOPD. While at high scanning speeds in keyhole mode, the shallow molten pool morphology and the large solidification rate allow the keyhole to evolve into an EOPD quickly. Nevertheless, in the conduction mode, the Marangoni effects along with a faster solidification rate induce EOPD. Finally, a ‘step’ variable power strategy is proposed to optimise the EOPD defects for the case with high volumetric energy density at low scanning speeds. This work provides a profound understanding and valuable insights into the quality control of LPBF fabrication.

Influence of Grinding Tool Mesh Size and Rotational Speed on Post-Machining Quality of CFRP Laminates by Acceleration Signal and Surface Roughness Analyses

In the grinding process, acceleration signals in both the time and frequency domains are valuable for monitoring and controlling vibration patterns, as factors such as rotational speed and the grinding head design significantly influence machining quality, efficiency, and finishing performance. This study analyzes the acceleration signals by dividing them into three distinct stages, pairing this analysis with microscopic morphology to investigate the grinding behavior of carbon fiber-reinforced polymer (CFRP). The findings reveal that high-frequency and low-amplitude vibrations enhance polishing efficiency and quality, whereas low-frequency and high amplitudes adversely affect grinding quality. Acceleration vibrations are more stable during the intermediate grinding stage compared to the initial and final stages, which helps reduce surface roughness, regardless of the rotational speed or grinding head mesh size. In addition, a coarse mesh (#40) results in an uneven surface due to a large amount of removed material, whereas a fine one (#120) results in lower material removal but continuous vertical vibrations due to the impact with the grinding surface, also resulting in poor surface quality. Thus, controlling the tool’s size and rotational speed is essential in reducing the amplitude of the vibration, allowing for maximizing the grinded CFRP surface quality.

Experimental investigation of laser texturing on surface roughness and wettability of PAHT CF15 fabricated by fused deposition modeling

AbstractFused deposition modeling (FDM) process has been emerged as an effective method for fabrication of different types of products without the need for expensive molds or material wasting subtractive processes. Polyamide composites possess higher mechanical properties, temperature resistance and inertness to many chemicals making them an attractive choice for many applications. This study focuses on the utilization of a nanosecond fiber laser texturing process as a post processing method for improving the surface finish and surface hydrophobicity of polyamide composite (PAHT CF15) produced through FDM process. PAHT CF15 is a high temperature resistant polyamide filament with 15% carbon fiber. These effects of texturing direction on surface finish and wettability of FDM printed PAHT CF15 samples were evaluated by texturing in two mutually perpendicular directions namely longitudinal and transverse. Experiments were also performed to determine the effect of laser power and scanning speed by varying the power at four levels, that is 20, 30, 40, and 50 W and scanning speed at two levels, that is 2000 and 4000 mm/s. Moisture absorption test of the textured surfaces were performed in an incubator at controlled temperature and relative humidity condition. A defocused laser beam was utilized to melt the upper surface of the 3D printed material in order to bring the changes at the surface level without causing surface ablation. It was observed that high speed laser processing can bring about the significant changes in surface finish, wettability and moisture absorption of the FDM printed parts.Highlights PAHT CF15 composites possess excellent mechanical properties. FDM printed PAHT CF15 parts have poor surface finish and low contact angles. Fiber lasers were employed to improve surface roughness. Wettability of textured surfaces was decreased by a maximum of 46%.

Surface Modification of Ultra-High-Molecular-Weight Polyethylene and Applications: A Review.

Ultra-high-molecular-weight polyethylene (UHMWPE) is often considered an ideal reinforcing material due to its extraordinary characteristics like high abrasion resistance, excellent toughness, and chemical stability. However, the poor surface properties have significantly hindered the progress of UHMWPE with high performance. This review is intended to introduce the physicochemical mechanisms of UHMWPE interfacial property modification. Therefore, this review provides a concise overview of the progress in diverse surface modification techniques for UHMWPE and their strengths and limitations as polymer reinforcement materials. Lastly, an overview of the potential and challenges of each surface modification has been summarized.

Studying the performance of quasi zero stiffness structure added to seat’s suspension based on various vehicle types

To elucidate the performance of quasi zero stiffness structure (QZSS) added to seat’s suspension on various vehicle models, three typical models of the vehicle including the car, soil compactor, and vehicle truck are used and established to study the QZSS under various simulations of vehicles. The experiment of soil compactor with seat suspension using QZSS has been also done to strengthen the research results. The result research at the time domain and frequency domain shows that QZSS added into seat’s suspension system is very effective in isolating operator’s seat vibrations in all three models. Especially, the QZSS is very effective when the vehicles are moving on poor road surfaces and high speeds. Besides, the performance of QZSS on the soil compactor’s seat is better than that of the vehicle truck and car. Therefore, this discovery can be a very useful reference for researching and applying QZSS to seat suspension in all off-road vehicles including earth-moving machinery and soil compactors.

Finite Element Analysis of Stress Distribution in Alkali-Peroxide Treated Epoxy Composites with Various Woven Cotton Structures

ABSTRACT The poor surface properties of woven epoxy-cotton composite structures have limited their use in industrial applications. Existing solutions using single treatment processes have been developed to address the challenges but have recorded appreciable degrees of success. This study has introduced a novel and synergistic alkali-peroxide treatment in addition to the use of five (5) variations of reinforcing woven structures (plain, matt, twill, herringbone, and satin) to develop the composites via the vacuum bagging molding process. This paper demonstrates the effectiveness of the dual treatment and different woven architectures in structure-related properties, particularly in the warp (machine) direction. The synergistic treatment showed a negative effect on the thermal stability of the resulting composites. The composite with the optimum weave structure in reinforcement capacity was validated using ANSYS FEA based on the numerical and experimental results, and the obtained results showed the possibility of simulating the tensile behavior of the composite structures.

Welding process stability in narrow-gap oscillating laser-MIG hybrid welding of titanium alloys with various oscillating patterns

Revealing the mechanism of laser oscillating patterns on the laser-MIG hybrid welding process stability was of great significance for improving weld formation and controlling porosity defect of titanium alloys. Convex welds were formed with poor surface formation using linear, 8-shaped and infinity oscillating laser. A circular oscillating laser with more uniform energy distribution favored the formation of concave weld. Weld porosity decreased by approximately 60 % when compared to laser with linear oscillating pattern. A keyhole with the maximum opening size was formed and fluctuated slightly. More laser-induced plasma (LIP) was ejected from the keyhole, which favored the enhancement of electric channel. Particle exchange between the arc and LIP was enhanced. Additionally, the arc burnt stably. The wire melting was accelerated to form smaller droplets, and the droplet transfer frequency increased by about 9.2 % compared with that via linear oscillating laser. Furthermore, the droplet impact force decreased by about 27.3 %. The liquid ridge (LR), formed by the droplet impact, was cushioned by the circular flow of molten metal. The droplet disturbance impact on keyhole wall was suppressed. Besides, when laser oscillated with circle pattern, the liquid metal was sufficiently diffused to rear part of molten pool, thereby suppressing convex welds.