Metal Surface Texture Research Articles

Study on the solder flow in a narrow gap with metal surface texture

Obvious voids in the solder in a narrow gap is a common problem that greatly affects the reliability of mechanical connections. Due to its high heating rate, laser soldering causes more severe voids and even evolves into dispersion of the solder. A method of metal surface texturing is put forward, in which the texture gradient is used to directionally transport solder for lower dispersity, and the pattern design of texture is used to reduce the void rate. The directional transport of solder is realized through the differences in oxidation degree and microstructure of stainless steel surface under different ultrafast laser scanning speeds. The discharge of voids in the solder is achieved through the reservation of the central area in the solder and the oscillation during the laser heating process. Based on the present method, the aggregation of solder is achieved, with the void rate of 18 % and the joining strength of 10.4 MPa.

Synergy Effect of Metal Surface Texture on the Low Friction of Graphene-Oxide Dispersed Oil

Synergy Effect of Metal Surface Texture on the Low Friction of Graphene-Oxide Dispersed Oil

Influence of the Metal Surface Texture on the Possibility of Controlling the Phase Transition of Water Droplets in the Single-Phase Regime

We experimentally studied the influence of the texture of copper and steel surfaces on the possibility of controlling the phase transition of water droplets in the single-phase regime. The texture of metals was formed by polishing and grinding, which corresponded to the finishing treatment of heat transfer surfaces in cooling systems for energy-saturated equipment. The samples were studied by microscopy and profilometry. The texture was estimated by three-dimensional roughness parameters. It was found that, with a 2–2.5-fold increase in roughness, the wetting of copper deteriorates (the contact angle increases from 66° to 93°), whereas the wetting of steel improves (the contact angle decreases from 89° to 71°). It was experimentally proven that, among the two main factors that affect the spreading diameter (wetting and roughness), wetting is the most significant. A hypothesis was formulated regarding the reason for the increase in the contact angle of 7–10° and the drop in the decrease rate of the contact diameter during the transition from the pinning to the mixed stage of droplet evaporation. It was found that an increase in the surface area of 0.1% leads to an increase in the total droplet evaporation rate of 4–6.5%.

The crucial role of heavy metals on the interaction of engineered nanoparticles with polystyrene microplastics

Despite continuous research on microplastics (MPs), studies exploring the complexity of interaction between MPs and other aqueous constituents in multi-solute systems are scarce. In this study, the uptake and release of nanoceria (CeNPs) by various polystyrene MPs (PSMPs) were investigated. Results showed that PSMPs in the presence of heavy metals (HMs) exhibited a substantially higher sorption affinity for isotropic charged CeNPs than PSMPs alone; this enhanced affinity was attributed to the formation of PSMP-HM-CeNP complexes. FE-SEM imaging reaffirmed that CeNP clusters adhered to PSMP surfaces in the presence of HMs. Such attachment varied dependent on valence state, atomic size of coexisting metal cations, surface texture, and functionalities of MPs. The HM-mediated complex formation on PSMP particles was suppressed at higher ionic strength because of competitive sorption and double-layer compression. Subsequent release of MP-adhered CeNPs and HMs varied significantly between aquatic media and various simulated digestive fluids, verifying the crucial role of MPs for transfer of engineered nanoparticles (ENPs) from natural environments into biota via ingestion of MPs and trophic transfer. Our results highlight the enhanced potential for MPs to accumulate and to transport ENPs when metallic contaminants are present, which adds to the current understanding of the environmental fate and adverse effects of MPs along with various waterborne contaminants in actual environments.

A combined electrochemical and theoretical analysis of environmentally benign polymer for corrosion protection of N80 steel in sweet corrosive environment

Abstract The corrosion inhibition efficiency of aniline, formaldehyde and piperazine based polymer (ADPD) on N80 steel in 3.5% NaCl solution saturated with carbon dioxide was investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, weight loss, scanning electrochemical microscopy (SECM), scanning electron microscopy (SEM) measurements, density functional theory (DFT) and molecular dynamics simulation (MD). The adsorption of polymer onto N80 steel surface followed Langmuir adsorption isotherm model. Potentiodynamic polarization study confirmed that inhibitor is mixed type with cathodic predominance. SECM study reveals the current values decreases with the increasing concentration of polymer. SEM study supports the smooth metal surface texture. DFT and MD calculations are in agreement with the experimental findings.

Ultra-broadband, wide angle absorber utilizing metal insulator multilayers stack with a multi-thickness metal surface texture

In this paper, we propose a facile route to fabricate a metal insulator multilayer stack to obtain ultra-broadband, wide angle behavior from the structure. The absorber, which covers near infrared (NIR) and visible (Vis) ranges, consists of a metal-insulator-metal-insulator (MIMI) multilayer where the middle metal layer has a variant thickness. It is found that this non-uniform thickness of the metal provides us with an absorption that is much broader compared to planar architecture. In the non-uniform case, each thickness is responsible for a specific wavelength range where the overall absorption is the superposition of these resonant responses and consequently a broad, perfect light absorption is attained. We first numerically examine the impact of different geometries on the overall light absorption property of the multilayer design. Afterward, we fabricate the designs and characterize them to experimentally verify our numerical findings. Characterizations show a good agreement with numerical results where the optimum absorption bandwidth for planar design is found to be 620 nm (380 nm–1000 nm) and it is significantly boosted to an amount of 1060 nm (350 nm–1410 nm) for multi-thickness case.

熱可塑性樹脂の微小穴への進入特性の評価

It is important to control adhesion between thermoplastics resin and metal in molding thermoplastics resin. There are some methods controlling adhesion, as usage, use of a release agent. In this study, we focused on texture on metal surface in order to control adhesion. It was reported that adhesion decreased on metal surface texture which consisted of microscale or nanoscale pores. Metal surface texture reduced adhesion with decreasing ratio of contact area between thermoplastics resin and metal surface. It is important that melted thermoplastics resin does not intrude to texture. The previous researches have not revealed the conditions, in which thermoplastics resin does not intrude to texture. We investigated influence of each parameter on intrusion of thermoplastics resin to texture. Investigated parameters are pressing time, trapped air in micropores, and diameter of micropores. And we got the result that the smaller diameter of the micropore is, the smaller intrusion depth is.

アルミニウム合金の表面色によるテクスチャ評価方法

In this paper, we carried out an experimental research for establishing the evaluation of metal's surface texture by analysis of surface color. The materials of samples used in the experiment were aluminum alloys (A2017, A5052), stainless steel (SUS304) and copper alloy (nickel silver C7541). The surfaces of samples were burnished by use of waterproof abrasive papers. The surface roughness of samples evaluated by arithmetical mean Ra, root mean square slope RΔq and mean width of the profile elements RSm. The experimental results showed strong correlation for three different roughness parameters. Consequently, “Ra” was used as roughness parameter. As Ra decreased, the glossiness exponentially increased. The evaluation method of surface color was applied to CIELAB. The lightness L* in CIELAB decreased as Ra decreased. Thus, it showed that relationship between L* and Ra inverse correlation between glossiness and Ra. Moreover, surface color of four different materials showed that the chromaticness of blue increased as Ra decreased.

Evaluation Method of Surface Texture by Surface Roughness based on Geometrical Product Specifications (GPS)

This paper describes a quantitative evaluation method for metal surface texture. We used surface roughness and glossiness as parameters to describe surface texture. Specimen surface roughness was evaluated based on geometrical product specification data taken from japanese industrial standards. The effects of surface roughness on glossiness were investigated by aluminum alloys. The relationship between the glossiness and the roughness height, the period of the roughness profile and the slope for the surface roughness processed by a vertical milling machine were studied for determining if the topography of the surface roughness affects the glossiness. The surface of the specimens were polished using abrasive paper and blasted, so that the arithmetical mean deviation, Ra, was less than 1.00 μm. The effects of roughness on glossiness were investigated on polished surfaces and blasted surfaces. The results show that the surface roughness shape and the glossiness prove to be effective indices for evaluating the surface textures of aluminum alloys.

Experimental Relationships between Surface Roughness, Glossiness and Color of Chromatic Colored Metals

This paper describes the establishment of an evaluation method for metal surface texture. The evaluation parameters used for surface texture were roughness, glossiness and color. Seven sample materials were studied: aluminum alloys (A2017, A5052), stainless steel (SUS304) and copper alloys (tough pitch copper C 1100, brass C2801, phosphor bronze C5191 and nickel silver C7541). The surfaces of all specimens were polished using waterproof abrasive papers. The correlation of the surface texture parameters for all specimens was investigated experimentally. The surface roughness of specimens was evaluated using the arithmetical mean roughness Ra. The method for evaluating surface color was assessed by using CIELAB color space. The CIELAB color space is one of a uniform color space defined by CIE (Commission Internationale de l'Eclairage) in 1976. The results indicated that as surface roughness value Ra decreased, as the glossiness value Gs(60°) increased exponentially. The lightness value L* of the CIELAB color space decreased, as surface roughness value Ra decreased. Thus, the relationship between the lightness value L* and surface roughness value Ra showed an inverse correlation with the glossiness value Gs(60°) and surface roughness value Ra. Moreover, the surface color showed that the blue hue increased, as the surface roughness value Ra decreased for all seven types of materials.

Cellular Porous Anodic Alumina Grown in Neutral Organic Electrolyte II. Transmission Electron Microscopy Examination of Ultrathin Cross Sections and a Model for Film Growth

Anodic coatings grown on aluminum in certain organic electrolytes have been studied by transmission electron microscopy examination of thin cross sections. The electrolytes have low water content and contain ethylene glycol as a solvent component and a dicarboxylate as solute. A cellular porous coating grows although aluminum is insoluble and oxide deposits with about 95% faradaic efficiency. Inner and outer layers in the oxide are easily distinguished, and it is found that the field strength of the outer layer is up to 50% higher than for conventional amorphous alumina due to a high concentration of incorporated organic species. The transition from barrier to porous growth occurs when cusps initiate at concavities that evolve from the initial metal surface texture. A cusp develops into a stable pore because the high field at this site causes Al ion ejection and the unusually small cation transport number in this oxide/organic composite is insufficient for oxide growth at the coating/electrolyte interface. © 2000 The Electrochemical Society. All rights reserved.

On the effect of metal surface texture on long-term resistance of vulcanized rubber-to-metal bonds under accelerated ageing

Methods for testing rubber-to-metal bonds are discussed and national and international standards currently in force are investigated. A new method for the prediction of longterm properties of rubber-to-metal bonds under accelerated ageing is introduced. In this method, named ‘peel-creep’, normal testpieces are submitted to forced ageing under constant load. Special attention is given to the surface texture of the metal used in the experiments.

On the effect of metal surface texture on long-term resistance of vulcanized rubber-to-metal bonds under accelerated ageing : E. Östman and S. Persson (Industrial Development Centre, SKERIA, Sweden)

A new method for the prediction of long-term properties of rubber-to-metal bonds under accelerated ageing is discussed. In this method, named «peell-creep», normal test pieces are submitted to forced ageing under constant load. Special attention has here been given to the surface texture of the metal used in the experiments

歯面清掃器の補綴臨床応用に関する研究 第３報 歯面清掃器噴射面に対する細菌付着

The purpose of this study is to investigate the relation between the metal surface texture and bacterial adherence. The surface of Au-Ag-Pd alloy was treated with or without air-powder abrasion. Seven standard strains and two clinical isolates were used. The alloys were mixed with [6-3H]-thimidine labelled bacteria. The radioactivity was measured with a scintilation counter. Streptococcus sanguis and clinical isolated Bacteroides gingivalis were adhered in a larger amount to the air-powder abraded alloy surface than to nonabraded alloy surface. These results indicated that careful consideration is needed for application of air-powder abrasive system on metal crown with secondary caries and periodontal disease.

ChemInform Abstract: ON THE ROLE OF MASS TRANSPORT IN HIGH RATE DISSOLUTION OF IRON AND NICKEL IN ECM ELECTROLYTES. I. CHLORIDE SOLUTIONS

AbstractDie anodische Hochgeschwindigkeitsauflösung von F e und Ni ,in 5 M NaCl‐Lösung wird im Hinblick auf die elektrochemische Werkzeugbearbeitung (ECM) in einer Strömungskanalzelle unter kontrollierten hydrodynamischen Bedingungen untersucht.

On the role of mass transport in high rate dissolution of iron and nickel in ECM electrolytes—I. Chloride solutions

High rate anodic dissolution of iron and nickel in 5 M NaCl was studied in a flow channel cell under controlled hydrodynamic conditions. Galvanostatic experiments were aimed at investigating the influence of current density and electrolyte flow rate on anode potential, current efficiency for metal dissolution and surface texture resulting from dissolution. Active dissolution at low current densities leads to surface etching and transpassive dissolution at high current densities leads to surface brightening. Transition from active to transpassive dissolution is mass transport controlled and is accompanied by a change in anode potential, surface microtexture and in case of iron by a change in the valence of metal dissolution.