Evolution Of Surface Morphology Research Articles

Evolution of phase, surface morphology and wettability of sputtered copper thin films on annealing in air: Formation of CuO/Cu2O/Cu nanocomposites

Evolution of phase, surface morphology and wettability of sputtered copper thin films on annealing in air: Formation of CuO/Cu2O/Cu nanocomposites

A method for determining efficiency parameters based on efficiency-quality graph in incremental sheet forming

This study reveals the mechanisms by which efficiency parameters affect surface quality, mechanical properties, and configuration offset in incremental sheet forming (ISF), focusing on surface morphology and microstructural evolution. By constructing an efficiency-quality graph, a method is developed to determine efficiency parameters that balance quality and efficiency synergistically. The results show that increasing Z and decreasing v intensify plowing and adhesion effects at the interface, degrading surface quality and enriching the presence of {001}<100> Cube and {112}<111> Copper textures, while the cross-sectional crystal orientation remains unaffected. Additionally, increasing Z enlarges grain size and reduces high-angle grain boundaries (HAGBs), amplifying micro-stress and defects, which deteriorates mechanical properties and increases configuration offset. Conversely, increasing v has minimal impact on mechanical properties but significantly increases configuration offset due to the rise in HAGBs, micro-stress, and defects. The efficiency-quality graph elucidates the complex synergistic relationship between forming efficiency and comprehensive quality of the formed parts, and the optimal efficiency parameters are identified by considering the priority order of different quality dimensions. Specifically, when prioritizing surface quality and hardness, the optimal parameters are Z=0.1mm and v=5000mm/min; when prioritizing configuration offset, the optimal parameters are Z=0.1mm and v=1000mm/min. Therefore, this study provides a comprehensive method for evaluating efficiency parameters in incremental sheet forming, emphasizing the importance of balancing efficiency with quality.

Nanosecond pulsed laser coloring of the CrMnFeCoNi high entropy alloy

High-entropy alloys (HEAs) possess great potential for applications in the aerospace and military fields due to their excellent performance. Surface coloring can endow HEAs diverse functions. However, achieving a multi-color surface with minimal surface damage and cost remains a significant challenge. In this study, surface coloring of the CrMnFeCoNi HEA was attempted by nanosecond pulsed laser irradiation in air, and the multi-color surface was achieved. The evolution of surface color and morphology with laser parameters was analyzed. Then, five typical colors were selected, and the corresponding morphologies and chemical compositions were characterized by various techniques. The results showed that the change in oxide layer thickness as well as the formation of chromium-rich β-spinel and Cr (VI) compounds induced noticeable changes in surface color. Accordingly, complex surface patterns with various stable colors were prepared on the HEA surface, demonstrating the potential application of nanosecond pulsed laser coloring of HEAs.

Concurrent Amorphization and Nanocatalyst Formation in Cu-Substituted Perovskite Oxide Surface: Effects on Oxygen Reduction Reaction at Elevated Temperatures.

The activity and durability of chemical/electrochemical catalysts are significantly influenced by their surface environments, highlighting the importance of thoroughly examining the catalyst surface. Here, Cu-substituted La0.6Sr0.4Co0.2Fe0.8O3-δ is selected, a state-of-the-art material for oxygen reduction reaction (ORR), to explore the real-time evolution of surface morphology and chemistry under a reducing atmosphere at elevated temperatures. Remarkably, in a pioneering observation, it is discovered that the perovskite surface starts to amorphize at an unusually low temperature of approximately 100 °C and multicomponent metal nanocatalysts additionally form on the amorphous surface as the temperature raises to 400 °C. Moreover, this investigation into the stability of the resulting amorphous layer under oxidizing conditions reveals that the amorphous structure can withstand a high-temperature oxidizing atmosphere (≥650 °C) only when it has undergone sufficient reduction for an extended period. Therefore, the coexistence of the active nanocatalysts and defective amorphous surface leads to a nearly 100% enhancement in the electrode resistance for the ORR over 200 h without significant degradation. These observations provide a new catalytic design strategy for using redox-dynamic perovskite oxide host materials.

Electrolyte engineering for optimizing anode/electrolyte interface towards superior aqueous zinc-ion batteries: A review

Aqueous zinc-ion batteries (AZIBs) are promising candidates for the large-scale energy storage systems due to their high intrinsic safety, cost-effectiveness and environmental friendliness. However, issues such as dendrite growth, hydrogen evolution reaction, and interfacial passivation occurring at the anode/electrolyte interface (AEI) have hindered their practical application. Constructing a stable AEI plays a key role in regulating zinc deposition and improving the cycle life of AZIBs. The fundamentals of AEI and the challenges faced by the Zn anode due to unstable interfaces are discussed. A comprehensive summary of electrolyte regulation strategies by electrolyte engineering to achieve a stable Zn anode is provided. The effectiveness evaluation techniques for stable AEI are also analyzed, including the interfacial chemistry and surface morphology evolution of the Zn anode. Finally, suggestions and perspectives for future research are offered about enabling a durable and stable AEI via electrolyte engineering, which may pave the way for developing high-performance AZIBs.

The interface mechanical and ablative evolution behaviors under different heat flux of multiphase HfC-SiC matrix composites

Multiphase HfC-SiC ceramic matrix composites were prepared by a combination process. The interface mechanics and ablation properties behaviors were investigated. Introducing the PyC-SiC interface, the composites showed a second-order pull-out mechanism. The mechanical failure model showed that fibers and matrix have different failure strain under load depending on the component that fails first. Moreover, the ablative airflow in the center area will spread to the edge area through the thermal shock microcracks generated. Increasing of the heat flux, the crack width gradually increased to be ditches. It accelerated the evolution of surface morphology, which showed HfC-SiC substrate was first transformed into Hf-Si-O solid solution on the process of phase transformation of oxidation products from 1680 ℃ to 2150 ℃, and eventually sintered into HfO2. The change in the morphology of oxidation product consumed more heat and protected the substrate from oxidation, resulting in improving the ablation resistance of composites.

Surface morphology evolution, microstructural response and mechanical property variation of Au-ion irradiated CrNbZrMoV, TiCrZrMoV, TiNbCrMoV, TiNbZrCrV and TiNbZrMoCr high-entropy alloy coatings

In this work, the CrNbZrMoV, TiCrZrMoV, TiNbCrMoV, TiNbZrCrV and TiNbZrMoCr refractory high-entropy alloy (RHEA) coatings (1.67∼2.77 μm of thickness) were prepared by magnetron sputtering. Then, 6 MeV Au-ion irradiations with 2.5 × 1015 to 1.0 × 1016 ions/cm2 fluences were performed on these coatings at 473 K, and the surface morphology, microstructure and mechanical property were investigated. The peak damage of the CrNbZrMoV, TiCrZrMoV, TiNbCrMoV, TiNbZrCrV and TiNbZrMoCr coatings under 1.0 × 1016 ions/cm2 fluence are 48, 48, 44, 48 and 48 dpa, respectively. The peak Au concentration of the CrNbZrMoV, TiCrZrMoV, TiNbCrMoV, TiNbZrCrV and TiNbZrMoCr coatings under 1.0 × 1016 ions/cm2 fluence are 4.27 × 103, 4.12 × 103, 4.13 × 103, 4.16 × 103 and 4.37 × 103 appm, respectively. The surface morphology of the CrNbZrMoV, TiCrZrMoV, TiNbZrCrV and TiNbZrMoCr coatings were smoothed obviously. For BCC TiNbCrMoV coating, irradiation caused the growth of the nanocrystalline. For amorphous coatings, the crystallization occurred in the CrNbZrMoV, TiCrZrMoV and TiNbZrMoCr coatings after 2.5 × 1015 fluence irradiation (≥12 dpa), while the TiNbZrCrV coating remain mainly amorphous structure after all irradiation. It was found that irradiation induced continuous crystallization occurred not only at the surface but also in the peak damage zone of the coating, and then grew inside the irradiated region. Apparent irradiation hardening was observed in all the coatings except the TiNbZrCrV coating. The structural stability of these coatings under the current irradiation condition was discussed. Preliminary study shows that the great irradiation tolerance of amorphous TiNbZrCrV coating may be related to the lowest electronegativity difference (Δχ = 0.121) and large atomic size difference (δ = 9.042 %) that stabilize the structure and inhibit atomic diffusion, respectively. These findings provide the guidance for the development of high irradiation tolerance materials for future nuclear energy applications with great structural stability.

Deuterium plasma induced preferential erosion in ultra-high temperature ceramics TiB2 and ZrB2*

Abstract Steady-state deuterium plasma exposures were performed on ultra-high temperature ceramics titanium diboride (TiB2) and zirconium diboride (ZrB2) using the PISCES-RF linear plasma device (LPD) as early screening for first wall, plasma-facing applications. Deuterium plasma exposures were performed using 40 eV ion energies at 240, 525, and 800 °C sample temperatures and 90 eV ion energies at 240 °C sample temperatures to analyze TiB2 and ZrB2 surface morphology and chemistry evolution behavior. Post-plasma exposure chemistry characterization of the near surface ( &lt; 50 nm) region of the samples all show transition metal enrichment, indicating boron preferential erosion. Transition metal to boron fractions vary with plasma exposure temperature under the 40 eV ion energy; metal enrichment is maximized at 800 °C and then minimized at 525 °C. SEM micrographs of all plasma exposed sample surfaces show no significant or noticeable plasma induced damage from cracking or blistering.

Effect of laser-induced grain growth on the electrochemical and immersion corrosion behavior of electrochemical deposited Ni coatings

In this study, the introduction of laser irradiation during the electrochemical deposition of Ni coatings was employed to investigate the evolution of surface morphology, microstructure, and residual stress. Furthermore, the impact of laser on corrosion performance was examined through electrochemical and immersion corrosion tests. The results showed that introducing a laser resulted in a uniform electrochemically deposited particle size distribution, and the shape evolved from granular to pyramidal. However, the average grain size increased from 0.4 ± 0.1 μm to 0.6 ± 0.3 μm after adding laser, and the grain morphology also transformed from equiaxed to columnar grains. In addition, the surface roughness increased from 34 ± 3 nm to 122 ± 16 nm compared to not adding a laser. The internal stress changed from 54 ± 17 MPa to −113 ± 19 MPa, indicating that the original tensile stress evolved into compressive stress. Electrochemical and immersion corrosion indicate that after adding laser, the passive current density decreased from 3.8 × 10−6 A·cm−2 to 6.9 × 10−7 A·cm−2 (reduced by approximately 81.8 %), indicating a significant improvement in corrosion resistance. This is attributed to the stability and density of the passive film. Although the average grain size and surface roughness increase, the uniformity of surface deposited particles improves the uniformity of electrochemical distribution, accelerates the formation of uniformly dense passive film, and limits the expansion of corrosion pits under the combined action of compressive stress.

Revealing the surface structure and morphology evolution of Co nanoparticle supported on ZrO2 surfaces

The optimization of structure-dependent activity of supported metal catalysts has driven the dynamic determination of the morphology of Co nanoparticles on ZrO2 using atomic-level simulations. Density functional theory (DFT) calculations combined with ab initio molecular dynamics (AIMD) simulations were used to investigate the surface structure, nucleation mechanism and morphology evolution of Con clusters supported on different ZrO2 facets. As the size of the Con (n = 1–5) cluster increases, the competition between Co-Co bonding and the interaction of Con clusters with the ZrO2 surface further promotes the nucleation of larger clusters. Co atoms prefer to nucleate into large clusters on both c-ZrO2(111) and t-ZrO2(101) surfaces, but this behavior is unfavorable on the m-ZrO2(-111) surface. The analysis of electric properties suggests that the types of hybrid orbitals and the number of electron transfer accounts for the difference in energies of Con clusters on ZrO2 surfaces. Further, the AIMD simulations verified the stable structure of small Co5 cluster obtained by DFT, and predicted the morphology of large Co13 clusters on ZrO2 surfaces under realistic reaction conditions, consistent with the experimental SAM images. Our work provides an intuitive understanding of structure and morphology evolution of catalysts for the targeted design of catalysts to achieve the desired activity and explore more reaction possibilities.

Evolution of tooth surface morphology and tribological properties of helical gears during mixed lubrication sliding wear

In mixed lubrication, the interplay of lubricant flows, solid asperity contact, and material wear between tooth surfaces creates complex and unpredictable contact states on tooth surface. To comprehensively understand the interaction between the lubrication and wear characteristics of the rough tooth surfaces of helical gears, this study established a mixed lubrication sliding wear calculation model for helical gears based on the mixed elastohydrodynamic lubrication model and Archard’s model. Specifically, the study aimed to examine the effects of surface topography features on average film thickness, contact area ratio, and accumulated wear at the meshing point. The findings demonstrated that the texture and power spectral density distributions of a non-Gaussian reconstructed surface closely resembled those of the actual ground surface. Furthermore, for non-Gaussian rough surfaces, a larger wavelength ratio enhanced microwedge motion, which increased film thickness and reduced wear. Additionally, a negatively skewed surface demonstrated better lubrication performance compared to both positively skewed and Gaussian surfaces. This improved performance is evident in the smaller contact area ratio and lower accumulated wear value of the negatively skewed surface.

Infrared microlens formation on chalcogenide polymer surface via femtosecond laser pulse ablation

In this study, we introduced micro-optical surface formation via femtosecond (fs) laser pulse scanning to chalcogenide polymer (ChP), a promising material for cost-effective infrared applications. Employing this method, we successfully fabricated a large-area poly(sulfur-random-(1,3-diisopropenylbenzene)) (S-r-DIB) microlens array (MLA) component. Each micro-concave spherical surface was crafted with a single fs laser pulse, serving as a micro-concave lens surface. We achieved a quasi-periodic MLA sample with over 2 × 105 micro-lenslets within a 10 mm × 10 mm footprint. Additionally, precise locating of laser pulse irradiation enabled us to create a hexagonal MLA with a filling factor over 37 %. Morphological investigations and imaging tests confirmed the adequate surface quality of the fabricated components, with its uniformity revealed by the virtual foci grid in near infrared region. To elucidate the forming conditions and mechanisms, we studied the evolution of surface morphology under various laser irradiation conditions. Laser induced damage thresholds of S70-r-DIB30 were experimentally determined for both 800 nm and 400 nm wavelengths under single- and multi-pulse irradiation scenarios. We identified the optimal fabrication fluence window as 115–205 mJ/cm2 with 800 nm single-pulse irradiation. The bandgap of the S70-r-DIB30 was estimated as 2.06 eV, and energy band analysis confirmed distinctions in ablation morphology. Furthermore, we investigated sub-surface morphology evolution using orthogonal ultrafast pump–probe imaging, revealing diversity compared to traditional inorganic and polymeric optical materials due to differing absorption and etching mechanisms. The elastic wave velocity of 3.2 km/s in this ChP and etching velocity of 0.7 μm/pulse were experimentally determined. These findings deepen our understanding of ChP material interaction with fs lasers, offering insights for potential applications such as surface engineering, substrate cutting, and micro-structure formation.

Ultrasonic Cavitation Erosion Behavior of GX40CrNiSi25-20 Cast Stainless Steel through Yb-YAG Surface Remelting.

Laser beam remelting is a relatively simple and highly effective technique for the physical modification of surfaces to improve resistance to cavitation erosion. In this study, we investigated the effect of laser remelting on the surface of cast stainless steel with 0.40% C, 25% Cr, 20% Ni, and 1.5% Si on cavitation erosion behavior in tap water. The investigation was conducted using a piezoceramic crystal vibrator apparatus. Base laser beam parameters were carefully selected to result in a defect-free surface (no porosity, material burn, cracks) with hardness capable of generating better resistance to cavitation erosion. The experimental results were compared with those of the reference material. Surface morphology and microstructure evolution after cavitation tests were analyzed using an optical metallographic microscope (OM), scanning electron microscope (SEM), and hardness tests to explore the mechanism of improving surface degradation resistance. The conducted research demonstrated that surfaces modified by laser remelting exhibit a 4.8-5.1 times greater increase in cavitation erosion resistance due to the homogenization of chemical composition and refinement of the microstructure, while maintaining the properties of the base material.

Phase-Field Modeling of Zinc Dendrite Growth in Aqueous Zinc Batteries

The growth of zinc dendrites poses a major challenge in developing stable aqueous zinc batteries. It is crucial to understand the mechanism underlying the dendrite growth and the influences of various factors on the process of dendrite growth. In this study, a phase field model is constructed to simulate the growth of zinc dendrite and investigate the temporal and spatial distributions of ions and electric potential in both static and flowing electrolytes. The influences of various critical factors, including overpotential, anisotropic strength and electrolyte flow rate, on the morphology evolution of electrodeposit are investigated. Results reveal that the surface morphology evolution is intimately dependent on the competition between ion transport and the electrochemical reaction, and it can be modulated by various parameters. In particular, flowing electrolyte not only enhances the convective ion transport but also suppresses the dendrite bifurcation on the surface, resulting in a uniform distribution of the concentration gradient and a compact deposit. However, nonuniformity induced by the flowing electrolyte from the inlet to outlet may impede the stable cycling of zinc anodes in the flow batteries. Therefore, further design and optimization of the flow field are desired for zinc-based flow batteries. This work provides insights into the growth process of zinc dendrites and the influences of several critical parameters, which could inform the design of stable aqueous zinc batteries. Figure 1

Modelling and experimental study of surface morphology evolution during layer growth on nanograting structures

Coating nano/micro-structured elements with a single or multi-layered film can greatly enhance their functionality. The experimental enhancement, however, is significantly limited by the smoothing and distortion of the structural profile after coating. This requires a comprehensive understanding of the layer growth behavior on nanoscale non-isotropic surface with a proper model to analyze and predict the structure evolution. Here, a simplified linear growth model with single free parameter was successfully used for analysis of the smoothening of grating grooves. The model enables a quantitative description of the evolution of surface morphology from substrate to the top surface with sub-nanometer accuracy. Based on this, the smoothing behavior of single-Si layer and W/Si multilayer growth on nanoscale gratings (period ∼ 40 nm) and flat substrates were studied experimentally, for applications in X-ray optics. The smoothing effect of the W/Si multilayer coating is more pronounced than that of the single Si layer for both substrate types. The corrugated nanogratings suppressed the smoothing effect as compared to the flat isotropic surface. These works provide new guidance to predict and control the growth of layers on nanostructures.

Harnessing ion beam erosion engineering for controlled self-assembly and tunable magnetic anisotropy in epitaxial films

The engineering of the surface morphology and the structure of the thin film is one of the essential technological assets for regulating the physical properties and functionalities of thin film-based devices. This study presents an easy and handy approach to tailor the surface structure of epitaxial thin films utilizing low-energy ion beam. Here, we investigate the evolution of the surface structure and magnetic anisotropy (MA) in epitaxial Fe/MgO (001) model systems subjected to multiple cycles of ion beam erosion (IBE) after thin film growth. The growth of Fe film occurs in the form of three–dimensional islands and exhibits intrinsic biaxial MA. Following a few cycles of IBE, an induced uniaxial magnetic anisotropy leads to a split in the hysteresis loop, and the film displays almost uniaxial magnetic switching behavior. More distinctly, we present a clear and conclusive evidence of (2 × 2) reconstruction of the Fe surface due to the atomic rearrangement by IBE. Furthermore, 57Fe isotope sensitive nuclear resonance scattering measurement provides insight into the depth-resolved magnetic information due to the modified surface topography. We also demonstrate that thermal annealing can reversibly tune the surface reconstruction and induced UMA. The feasibility of the IBE technique by adequately selecting IBE parameters for surface structure modification has been highlighted apart from conventional tailoring of the morphology for the tuning of UMA and introduces a new dimension to our understanding of self-assembled surface morphology evolution by IBE.

The surface morphologies and internal pores evolution of a CuSn10 alloy fabricated by laser powder bed fusion

The fabrication of high quality copper alloys using laser powder bed fusion (LPBF) technology remains challenging due to their low laser absorption and high thermal conductivity. LPBF often involves intrinsic defects, such as rough surface and internal pores, which largely deteriorate the performance of as-built copper alloy components. Here we studied the effect of scanning speed on the evolution of surface morphologies and internal pores of LPBF-fabricated CuSn10 alloy. The melt flow behaviors were studied by both experiments and in situ observations where combined a high-speed camera with an infrared thermal imager. With increasing the scanning speed, the morphology of melt track evolves from a continuous track to a discontinuous one, whereas the internal defects change from a great number of spherical pores to many irregular pores. A higher scanning speed decreases the peak temperature of the melt pool and causes less overlaps between neighboring melt tracks, thus deteriorating wetting behaviors. It is expected that the obtained results are beneficial for guiding the additive manufacturing of copper alloy parts with high metallurgical quality and thus promoting their industrial applications.

Development of Ce/Cu co-doped dendritic mesoporous silica nanoparticles (DMSNs) as novel abrasive systems toward high-performance chemical mechanical polishing

Development of novel abrasive systems with functional activities and physicochemical properties are of great significance in the reactive oxygen species (ROS)-enhanced chemical mechanical polishing. In this work, Ce single-doped and Ce/Cu co-doped dendritic mesoporous silica nanoparticles (DMSNs), namely Ce−DMSNs and Ce/Cu−DMSNs, were produced via a simple impregnation and thermolysis procedure. The Ce and/or Cu species involved in DMSNs frameworks were characterized through X-ray diffractometry, infrared spectroscopy, scanning electron microscopy, energy dispersive spectrometry, transmission electron microscopy, X-ray photoelectron spectroscopy, and nitrogen adsorption/desorption techniques. We report the evolution of surface morphology and roughness, defects, peak-to-valley data, image surface area difference, and material removal efficiency during ROS-enhanced polishing experiments toward silica materials. All the pure, Ce single-doped, and Ce/Cu co-doped DMSNs abrasive systems offered nearly defect-free surfaces with close-to-atom scale roughness. It might be attributed to the “springlike effect” and “soft polishing/abrasion”, possibly originating from the low-modulus DMSNs carriers. Among these abrasives, the Ce/Cu co-doped DMSNs systems achieved an evident improvement in removal efficiency, especially under ultraviolet irradiation-assisted polishing conditions. The coexisted Ce(Ⅲ)/Ce(Ⅳ) and Cu(Ⅰ)/Cu(Ⅱ) couples might be responsible for the effective production of ROS in photocatalysis and Fenton-like processes, thereby contributing to the Si–OH and Ce(Ⅲ)−O–Si bonding formations. The role of the developed Ce/Cu co-doped DMSNs abrasive systems in ROS-enhanced polishing processes was discussed.

Investigation of interfacial properties of Ag–Cu/Si3N4 composite ceramic substrates by interface reaction of Si3N4 and CuO

The surface metallization of Si3N4 ceramics with the Ag–Cu conductive paste containing CuO was systematically investigated. The interfacial reactions between CuO and Si3N4 promoted the surface metallization of the ceramic substrate in an argon atmosphere. The effects of Ag and Cu relative contents on the evolution of the thick film surface morphology were studied. The electrical properties and tensile strength of composite ceramic substrates were enhanced through the generation of Ag–Cu eutectic solution within the thick film layer. The effect of brazing time on the properties of Ag–Cu/Si3N4 composite ceramic substrates was investigated. Mechanical testing and scanning electron microscopy (SEM) were used to analyze the interface tensile strength of the Ag–Cu/Si3N4 composite substrates and the morphology of the Ag–Cu film, and the bonding mechanism of the composite ceramic substrate was studied. When the sample was brazed at 800 °C for 20 min, the maximum tensile strength of 23.6 MPa between the Ag–Cu film and ceramic substrate was obtained, the lowest resistivity of 6.22 μΩ•cm was obtained. The bonding interface between thick film layer and the ceramic substrate formed the Ag–Cu mechanical structure was benefit for improving the comprehensive performance of the Cu/Si3N4 composite ceramic substrate.

Numerical simulation of free-surface evolution in laser polishing of 100 Cr6 bearing steel

Abstract This research focuses on the laser surface polishing process of 100 Cr6, employing a moving Gaussian heat source. It establishes a two-dimensional transient model for laser polishing, taking into account the integrated effects of fluid flow and temperature fields, as well as the combined influence of capillary and thermocapillary forces. The model was used to perform numerical simulations to study the evolution of surface morphology during the laser polishing process. The investigation specifically examines how laser power and scanning speed influence the quality of the polishing outcome. The results demonstrate that an optimal surface roughness of approximately 0.571 μm is attained at a laser power setting of 200 W and a scanning speed of 300 mm/s.