Substrate roughness

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Modification of a Substrate Roughness for a Fabrication of Freestanding Electroplated Metallic Microstructures

Modification of a Substrate Roughness for a Fabrication of Freestanding Electroplated Metallic Microstructures

This study aims to demonstrate a simple fabrication technique of freestanding electroplated copper microstructure by modifying the substrate roughness. With the modification of substrate roughness until a magnitude of adhesive force locking a metallic microstructure to the substrate becomes weaker than that of induced intrinsic force inside the microstructure during the electroplating, deposited metallic microstructures will be spontaneously released from the substrate after the electroplating process. The fabrication technique started with a polishing of a stainless-steel substrate following by a patterning of a photoresist mold of microstructures. The copper was then electroplated inside the mold until a desired thickness was achieved. After that, the copper microstructure was released when removing the photoresist mold. Two experiments were conducted to investigate the effects of substrate roughness simultaneously with electroplated structure’s size and electroplated structure’s width-to-length ratio on a detachment possibility. From both experiments, the results showed that the electroplated structure with a smaller size and smaller width-to-length ratio was more easily detached from the substrate for a given substrate roughness. In addition, for the same electroplated structure, a substrate with less roughness allowed a detachment of electroplated structure more easily. However, both substrate’s roughness and electroplated structure’s size should be small enough in order to have the electroplated structures peel off. From the experiment results, if the multiplicity between the substrate’s roughness and the electroplated structure’s area was smaller than 5 x 10 -4 mm x mm 2 , the detachment possibility of electroplated structure from the

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Use of laser interferometry for measuring concrete substrate roughness in patch repairs

Use of laser interferometry for measuring concrete substrate roughness in patch repairs

The surface roughness of concrete substrates can be characterised by comparing them with standard Concrete Surface Profiles (CSP) which have been produced by ICRI in the form of nine plastic model surfaces [9]. These profiles replicate different levels of surface roughness obtained by different methods of concrete removal. Each profile is assigned a CSP number starting from CSP1 (acid etched/almost flat) up to CSP9 (heavily scarified/very rough). ASTM D7682 [10] describes a method to obtain a permanent record of a concrete surface that has been abraded or roughened. For this purpose, a replica putty is used to obtain a replica coupon of the concrete surface. Next, the replica coupon is either visually compared to the nine plastic model surfaces produced by ICRI [9] or it is measured by a specially designed micrometre to determine its depth.

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Measurement and characterisation of concrete substrate roughness in patch repairs

Measurement and characterisation of concrete substrate roughness in patch repairs

An extensive research programme was carried out in order to measure and characterise the surface roughness of concrete surfaces prior to patch repairs in a much more accurate and reliable way and at the same time prove the ability of RRH to produce much rougher surfaces. Forty eight concrete slab specimens designated S1-S48 and with dimensions of 400 x 400 x 125 mm were produced in four groups. Each group had a different w/c ratio and consisted of twelve slabs cast in six different mixes. In total twenty-four mixes were produced. Two slabs and six 100 mm cubes were produced from each mix. The w/c ratios of groups 1, 2, 3 and 4 were 0.4, 0.45, 0.50 and 0.55 respectively. Details of all slab mixes are shown in Table 1.

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Effect of substrate surface roughness on morphological and topography of 
		nickel alumina thin film

Effect of substrate surface roughness on morphological and topography of nickel alumina thin film

The value of maximum velocity differs with each substrate roughness and quite low for smoother substrate. Based on Fang et al. 2008 and Isha et al. 2012, this work is defined that in Section I, the thickness of the coating film increases as the viscous pull drag is proportional to withdrawal velocity. However as υ further increases in Section II, higher amount of sol gel solution was pulled up in a relatively shorter time. With the lack of sufficient evaporation time, the gravity force leads the sol gel solution drown back into pool before the solid sol-gel thin film manage to be formed completely on the substrate surface. The outcome of the withdrawal speed factor had created a competition between drag force (solution film moving upward) and gravity (solution film moving downward) as shown in Figure-1 which determines the variation of final solid nickel-alumina thin film thickness which is similar to the reported by Zangouei et al. 2010.

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Abstract surface growth modelling with application to graphene

Abstract surface growth modelling with application to graphene

The first characteristic feature of graphene growth on copper we investigate in this thesis is surface roughness. A number of the effects we described in the previous chapter indicate the high level of interaction between a mobile copper surface and the growing graphene layer. We discussed recent findings of graphene growth on nearly molten [129] and on liquid surfaces [39, 23], particularly noting that the latter led to formation of highly regular, single layer graphene islands. We also saw from a typical experimental CVD environment (Figure 2.3) that a great deal of copper sublimation occurs during a typical surface preparation and CVD growth run. Finally, a structural feedback effect has been noted, whereby the copper surface restructures by faceting only after CVD growth of a graphene overlayer [141]. Combined, these observations strongly imply that the Cu substrate can be far from equilibrium during CVD growth, and hence cannot be considered as a perfectly static crystal facet. The role of substrate roughness in controlling graphene nucleation has been described as pivotal [60], but this role has yet to be included in any kinetic growth model based on rate equations.

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Spatial variability, structure and composition of crustose algal communities in Diadema africanum barrens

Spatial variability, structure and composition of crustose algal communities in Diadema africanum barrens

A multiple regression model (DistLM analysis) showed that variability in community structure was sig- nificantly related to five environmental variables. Wave exposure was the variable that most contributed to spa- tial differences between algal communities, but urchin density and substrate roughness were also important. Productivity and depth had limited influence. The dbRDA analysis showed that environmental variables had different levels of influence at different spatial scales. On the largest scale, wave exposure and pro- ductivity were the most dominant factors relating to algal community structure, with a clear ordination of samples observed from N to SE sectors. Urchin density, rough- ness and depth were related to algal community vari- ability on the medium and small spatial scales. Samples from each sector as well as the samples from within each site were ordered along the second axis according to the increase of these variables.

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Characteristics and Mechanism of Cu Films Fabricated at Room Temperature by Aerosol Deposition

Characteristics and Mechanism of Cu Films Fabricated at Room Temperature by Aerosol Deposition

Generally, ceramic particles with high hardness during the AD process can form the anchoring layers on metal and glass substrate with relatively low hardness [23]. However, with metallic particles that have a ductile property, it is difficult to form the anchoring layer on the hard ceramic substrate. Therefore, the bonding be- tween metallic particles and the ceramic substrate is de- termined by the mechanical interlocking [20], and thereby the substrate roughness can considerably affect the adhesion strength. Figure 1a, b shows the surface roughness of the Al 2 O 3 substrate with different root-

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Online Full Text

Online Full Text

The purpose of the present paper is to investigate the influence of the interfaces roughness on stress distribution by using finite element (FE) modeling of TBC systems. FE modeling of TBC systems on aluminum alloys is rare and most researches were about simulation of coating on super alloys. High temperature application of these alloys cause forming of TGO layer between BC and TC which is the vital failure mechanism. Bengtsson and Persson [8] and also Widjaja et al. [9] presented FE analysis for the development of residual stresses during spraying of zirconia-based thermal barrier coatings. It was assumed a flat interfaces hypothesis between dissimilar materials, in order to simplify the approach.

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Optical Properties of Nanocrystalline Silicon Thin Films in Wider Regions of Wavelength

Optical Properties of Nanocrystalline Silicon Thin Films in Wider Regions of Wavelength

Nanocrystalline silicon thin films were prepared on corning (7059) glass substrates by means of a 150 MHz very high frequency plasma-enhanced chemical vapour deposition. An analysis about the effect of deposition times and substrate temperatures on the optical properties of nanocrystalline silicon is reported. Analysis by UV-Vis-Nir spectrophotometer showed that nc-Si films were almost transparent throughout the visible and infrared (IR) region mainly at   500 nm, while strongly absorbed incident light occurred in the ultraviolet (UV) region. A blue-shift changes at energy around 2.3 eV is observed for absoprtion coefficient if compared to those of bulk silicon crystal due to quantum confinement of nc-Si. The effect of film thickness showed a strong relation in the absorption coefficient value. Thicker films at longer deposition times and lower substrate temperatures reduced absorption coefficient of the films. However, grain size and surface roughness also plays a major role. Optical energy band gap, E g opt deduced from Tauc’s plot were found to

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Effect of surface roughness on coating SiO2-P2O5-CaO-ZrO2 upon Zirconium by Sol-Gel Method

Effect of surface roughness on coating SiO2-P2O5-CaO-ZrO2 upon Zirconium by Sol-Gel Method

Detachment or crushing of the surface layer during the usage a basic defect and problem of the coatings. This can lead to economic losses and poisoning of the body implants. In general, coating adhesion strentgh to the substrate depends on metallurgical, mechanical, physical and chemical mechanisms. Forces between atoms have various bond strengths. Forces between atoms with van der Waals bonds have the lowest bond strengths. The hydrogen, metal and ionic bonds are located after it while the highest bond strength is associated with covalent bonds. The adhesion strength of the coatings depends on several parameters including coating method, coating material, substrate material, coating conditions and so on. Since the adhesion is one of the most important parameters which determines the quality of the coatings and in case that the coated piece requires high adhesion strength while being used, the applied method for coating should provide the necessary adhesion strength. Improvement of the biocompatibility of metals and alloys is done through surface science and technology and creating coating on the surface or surface corrective action [10].

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Attachment to challenging substrates – fouling, roughness and limits of adhesion in the northern clingfish (Gobiesox maeandricus)

Attachment to challenging substrates – fouling, roughness and limits of adhesion in the northern clingfish (Gobiesox maeandricus)

Two competing processes affect surface roughness as a biofilm develops. The deposition of EPS smooths rough surfaces by filling in the ‘valleys’, but the growth of macroalgae and the settlement of invertebrates increase surface roughness (Ditsche et al., 2014). Compared with the surface irregularities of the primary substrates, the surface irregularities caused by macroalgae can be considerably larger (Fig. 3). The clingfish’s flexible suction disc and hierarchical microstructures can adapt to these surfaces if a few flexible macroalgae are present. However, if too many higher macroalgae were growing on the surface, the fish was unable to cling onto the surface (P.D., personal observation). Our observation is in accordance with the field observations for the sister species Gobiesox barbatulus, which prefers habitats with little or no periphyton and macroalgae (Pires and Gibran, 2011).

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Characteristics of Indium Tin Oxide (ITO) Glass Re Used from Old TFT LCD Panel

Characteristics of Indium Tin Oxide (ITO) Glass Re Used from Old TFT LCD Panel

from waste glass of old TFT-LCD panel. Most of the crashed glass is dissolved in molten bath for purification, and it is rebuilt as glass substrate or other glass products. The conventional recycling process of glass substrate is inefficient with high processing cost and long processing time. In this study, new approach to re-use without crushing was attempted. ITO glass substrate was separated from old TFT- LCD in its form, and glass substrate was re-used by separating ITO layer from it. After that, surface roughness and optical properties of the re-used glass substrate was characterized in order to determine whether it is still available to apply to ITO glass substrate. Also, the properties were compared with newly produced glass substrates. Finally, ITO

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Effect of accelerated aging treatment on a surface property and dynamic mechanical properties of commercial wood-based panels

Effect of accelerated aging treatment on a surface property and dynamic mechanical properties of commercial wood-based panels

Surface roughness, a surface property that is considered as latent, becomes notable when a panel is subjected to conditions that change its properties, such humidity. Numerous studies have reported surface roughness of wood-based panel products [14–20]. However, less infor- mation is available on surface roughness of panel as function of accelerated aging. A study exposing medium density fiberboard (MDF) to some level of relative humidity (RH) found that roughness values increased as panels were exposed to higher humidity levels ranging from 65 to 85% [21]. However, the RH exposure was used for once until the intended equilibrium moisture content of MDF was reached. A previous study on hardboard and MDF subjected to one cycle of 50–86–50% RH exposure [22] and found roughness instability after re-exposure to lower RH. Those RH exposures mentioned above provide insufficient information on panel surface instability that might occur owing to natural swelling and shrinkage dur- ing service life.

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Growth of Zinc Oxide Nanorods Using Various Seed Layer Annealing Temperatures and Substrate Materials

Growth of Zinc Oxide Nanorods Using Various Seed Layer Annealing Temperatures and Substrate Materials

various substrate materials (silicon, glass, and fluorine doped tin oxide (FTO) coated glass). Compared to other fabrication methods such as chemical vapor deposition (CVD), sputtering, pulsed laser deposition (PLD), and thermal evaporation, the sol-gel solution provides the advantages of an environmentally friendly process, simplicity, and low-cost fabrication, as well as a large-area process capability [9-11]. The seed annealing temperature was a critical factor in the growth of the ZnO NRs. At a certain seed annealing temperature, the lengths of the NRs grown on the various substrates showed no clear difference, whereas the crystallinity of the NRs grown on silicon was better than that of the NRs grown on the other substrates (glass and FTO). With increasing growth times, the length and density of the NRs increased and decreased, respectively, leading to well-aligned NRs on the substrate.

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Broadband Substrate to Substrate Interconnection

Broadband Substrate to Substrate Interconnection

operating bandwidth. Approaches using multiple bond wires [1–5] or compensated microstrip stubs [6– 11] can broaden the bandwidth of such interconnections, but none of them exceed 20 GHz frequencies. It is more important that compensated open stubs are used to broaden the bandwidth of bond wire interconnection in [4–7], but in most cases, the required compensated open stubs must be narrower than 0.1 mm, which is impossible to fabricate based on current printed circuit substrate (PCB) or low temperature co-fired ceramic (LTCC) fabrication process.

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Human Roughness Perception and Possible Factors Effecting Roughness Sensation

Human Roughness Perception and Possible Factors Effecting Roughness Sensation

These experiments were repeated for two different temperatures: room temperature and body temperature. The main motivation for this was to predict the perceived roughness during oral processing. The previous experiments reported in Aktar, Chen, Ettelaie, and Holmes (2015a) and Aktar, Chen, Ettelaie, and Holmes (2015b) showed that the tongue and fingertip had similar texture discrimination capabilities, and this was used as evidence to support using fingertip assessments for estimating the oral conditions for roughness. It should be noted that such estimation of the tongue’s roughness sensation is not supported by concrete evidence but can only be used as an estimate.

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Containing the Catalyst: Diameter Controlled Ge Nanowire Growth

Containing the Catalyst: Diameter Controlled Ge Nanowire Growth

Although a shi towards smaller diameter Ge nanowires and some narrowing of the diameter distribution was seen upon etching the metal seed catalysts into the Si substrate before growth, the mean diameter of the nanowires still lies reasonably far from the mean diameter of the initial seed nanoparticles used (9.3 2.5 nm, Fig. 2). The discrepancy between the diameter of the Ge nanowires and the diameters of the Ag nanoparticles used to seed their growth can be explained by the nature of the Ag particles themselves and how they are depos- ited onto the substrate. The Ag particles are oleylamine stabi- lized in order to prevent them from agglomerating. However the interparticle separation that this type of stabilisation offers on the substrate is of the same order of magnitude of the capping ligand 2 nm. 44 This interparticle separation can be increased

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Investigations into the impact of various substrates and ZnO ultra thin seed layers prepared by atomic layer deposition on growth of ZnO nanowire array

Investigations into the impact of various substrates and ZnO ultra thin seed layers prepared by atomic layer deposition on growth of ZnO nanowire array

We demonstrate that the growth of the ZnO NWs on ultra-thin seed layers is strongly influenced by the sub- strates and thickness of the seed films. NWs could be obtained on the smooth substrates covered with seed layers whose thickness is larger than 4 nm and have good alignment when roughness of the seed layers is also suitable. Besides, it is found that the thickness of the seed layers affects fluctuation amplitude and fre- quency of the roughness, which affects the alignment of the resulting NWs in succession. However, the crystal defects were influenced greatly by substrates instead of seed layers. The research provides prospect for prepar- ation of the ZnO NWs on thin seed layers.

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Effect of two-step pretreatment on cobalt contents and surface roughness of tungsten carbide substrate prior to diamond coating

Effect of two-step pretreatment on cobalt contents and surface roughness of tungsten carbide substrate prior to diamond coating

A well-known problem is the poor adhesion of diamond films on tungsten carbide due to the Co-binder that catalyzes the formation of graphite. A two step of the chemical pretreatment is the most effective method to etch tungsten carbide at the surface of the substrate in order to solve poor adhesion problem. first step with Murakami's reagent and the second step of the process are carried out by an etch in a solution of hydrochloric acid and hydrogen peroxide in deionized water or a solution of sulfuric acid and hydrogen peroxide. Surprisingly pretreatment with agents such as Murakami’s solution is the most effective pretreatment in term of quality and adhesion of diamond coating on WC-Co substrate due to mechanical interlocking. But until now it is not declare the most effective etching time and also it was not reported using a solution of hydrochloric acid and hydrogen peroxide in deionized water as a second step of the process.

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Numerical Simulation of the Thin Film Coating Flow in Two Dimension

Numerical Simulation of the Thin Film Coating Flow in Two Dimension

We proposed a two-dimension model of slip coating under isosceles triangle and isosceles trapezoid substrate, and thin film coating fluid motions under different configuration parameters were simulated. It is pointed out that the key factor determining the turbulence generation and evolution is the parameter of sub- stratum surface nature, with the increase of basal plate roughness, flow separa- tion phenomenon of thin film coating fluid occurs, accompanied by the vortices. Increasing unevenness r will make the eddy current phenomenon more and more obvious, and effect the location of vortex generation. The effects of the change of Reynolds number on turbulent appearance and action area are studied, compared with the unevenness, the Reynolds number for the eddy current gen- eration and development is not the dominant factor. The velocity contours of fluid field on different substrate surfaces are shown, and the impact of substrate geometry on the backwater region is analyzed. The center dead zones exists can be taken as a reference to judge whether the vortex exists.

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