Surface Roughness of SiGe/Si(110) Formed by Stress-Induced Twins and the Solution to Produce Smooth Surface

AbstractThe aim of the work is to show both the similarities and differences in the formation of deformation-induced roughness in contact compression in the presence of oil and the problem of free surface roughing during uniaxial stretching in a plastic area. The relationships between changes in the roughness are caused by the deformation of the sample and the viscosity of oil at the contact area. It has been shown that normal contact loading with the presence of oil initially leads to an increase in surface roughness, then to its smoothening. The results of the experimental research have been compared with numerical simulation made using FSI (Fluid Structure Interaction) and ABAQUS systems. Using finite element calculations, it was possible to explain the phenomenon of roughness formation on the surface of a smooth steel sample. The changes in the structure of the smooth surface resulting from compression in the presence of oil are caused by the rotation and deformation of surface grains. The roughness of this structure is dependent on the viscosity of oil: the more viscous the liquid is, the rougher texture is formed.

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Capillary Forces Described by Effective Contact Angle Distributions via Simulations of the Centrifuge Technique

MRS Advances ◽

10.1557/adv.2016.516 ◽

2016 ◽

Vol 1 (31) ◽

pp. 2237-2245

Author(s):

Myles Thomas ◽

Elizabeth Krenek ◽

Stephen Beaudoin

Keyword(s):

Surface Roughness ◽

Contact Angle ◽

Smooth Surface ◽

Adhesion Force ◽

Capillary Forces ◽

Angle Distribution ◽

Particle Adhesion ◽

Multiple Factors ◽

Effective Contact ◽

Condensed Moisture

ABSTRACTUnderstanding particle adhesion is vital to any industry where particulate systems are involved. There are multiple factors that affect the strength of the adhesion force, including the physical properties of the interacting materials and the system conditions. Surface roughness on the particles and the surfaces to which they adhere, including roughness at the nanoscale, is critically important to the adhesion force. The focus of this work is on the capillary force that dominates the adhesion whenever condensed moisture is present. Theoretical capillary forces were calculated for smooth particles adhered to smooth and rough surfaces. Simulations of the classical centrifuge technique used to describe particle adhesion to surfaces were performed based on these forces. A model was developed to describe the adhesion of the particles to the rough surface in terms of the adhesion to a smooth surface and an ‘effective’ contact angle distribution.

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Mechanochemical Polishing of Single Crystal Diamond with Mixture of Oxidizing Agents

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.315-316.852 ◽

2006 ◽

Vol 315-316 ◽

pp. 852-855 ◽

Cited By ~ 2

Author(s):

Cheng Yong Wang ◽

C. Chen ◽

Yue Xian Song

Keyword(s):

Surface Roughness ◽

Single Crystal ◽

Smooth Surface ◽

Removal Rate ◽

Polishing Process ◽

Iron Plate ◽

Oxidizing Agents ◽

Single Crystal Diamond ◽

Lower Temperature ◽

And Control

In order to achieve the smooth surface of diamond, several kinds of mixture oxidizing agents have been used to polish the single crystal diamond by a designed polishing apparatus. The existing of graphite and amorphous carbon has been found in the surface of diamond after polishing. The mechanochemical actions of oxidizing agents and the polishing iron plate have been proved. The mixture of oxidizing agents can decrease the polishing temperature so that the super-smooth surface of single crystal diamond can be achieved at lower temperature. The method provided is benefit not only to simplify polishing device and control the polishing process, but also to improve the removal rate and surface roughness.

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Study on the Machining Parameters in Polishing Single-Crystal SiC Wafers with SG Films

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.589-590.457 ◽

2013 ◽

Vol 589-590 ◽

pp. 457-463 ◽

Cited By ~ 2

Author(s):

Zhi Du ◽

Jing Lu ◽

Cong Fu Fang ◽

Hui Huang ◽

Xi Peng Xu

Keyword(s):

Surface Roughness ◽

Single Crystal ◽

Smooth Surface ◽

Sol Gel ◽

Machining Parameters ◽

Processing Quality ◽

Rotating Speed ◽

Single Crystal Sic ◽

Sic Wafer ◽

Diamond Abrasive

In this paper, diamond abrasive SG films were prepared by means of sol-gel technology for polishing single-crystal SiC wafers. The effects of machining parameters on processing quality including pressure, rotating speed and polishing time were investigated, respectively. The results indicated that the surface roughness decreased with increasing polishing time. While for pressure and rotating speed, there were inflections existing. Polishing SiC wafer under optimized machining parameters, an ultra smooth surface with the roughness of 3.7 nm could be achieved using 40 μm diamond grits.

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Calculation of Optimal Surface Roughness With Respect to Lift/Drag Forces Acting on Wind Turbine Blade

Volume 3B: Oil and Gas Applications; Organic Rankine Cycle Power Systems; Supercritical CO2 Power Cycles; Wind Energy ◽

10.1115/gt2014-25416 ◽

2014 ◽

Cited By ~ 2

Author(s):

Xuerui Mao ◽

Simon Hogg

Keyword(s):

Surface Roughness ◽

Boundary Conditions ◽

Smooth Surface ◽

Adjoint Equation ◽

Turbine Blades ◽

Leading Edge ◽

Sensitivity Study ◽

Small Magnitude ◽

Viscous Forces ◽

Drag Forces

Roughness on the surface of turbine blades induced by icing, dirt, erosion or manufacturing imperfections changes the aerodynamic configurations of wind turbines and reduces the power generation efficiency. In this work, a modified NACA0024 aerofoil is adopted to study effects of surface roughness on lift/drag forces. Three Reynolds numbers, 1000, 2000 and 5000 and a range of angles of attack [0°,20°] are studied. Since the magnitude of the roughness is small, it can be modelled as non-zero velocity boundary conditions imposed on the smooth surface without roughness. The flow with surface roughness can be therefore decomposed as the sum of a flow without roughness and a flow induced by roughness (or the velocity boundary conditions). The first flow can be obtained by solving the Navier-Stokes (NS) equation while the second one is governed by the linearized NS equation. Correspondingly the lift and drag forces acting on the aerofoil can be also decomposed as the sum of a force without considering roughness and a force induced by roughness. Instead of studying a particular type or distribution of roughness, we calculate the optimal roughness, which changes aerodynamic forces most effectively. This optimal roughness is obtained through a sensitivity study by solving an adjoint equation of the linearized NS equation. It is found that the optimal roughness with respect to both drag and lift forces is concentrated around the trailing edge and upper leading edge of the aerofoil and the lift is much more sensitive to roughness than the drag. Then the optimal roughness with a small magnitude is added to the smooth aerofoil geometry and this new geometry is tested through direct numerical simulations (DNS). It is found that the optimal roughness with a small magnitude (e-norm, defined as the square integration of the roughness around the surface, 0.001) induces over 10% change of the lift. Comparing the forces acting on the smooth surface and on the rough surface, it is noticed that the roughness changes the pressure force significantly while has little influence on the viscous forces. The pressure distribution is further inspected to study mechanisms of the effects of roughness on forces.

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Microstructures of Ultrathin Films of Sputtered PbTiO3

MRS Proceedings ◽

10.1557/proc-361-105 ◽

1994 ◽

Vol 361 ◽

Cited By ~ 1

Author(s):

Kiyotaka Wasa ◽

T. Satoh ◽

K. Tab Ata ◽

H. Adachi ◽

Y. Ichikawa ◽

...

Keyword(s):

Thin Films ◽

Surface Roughness ◽

Ultrathin Films ◽

Crystal Orientation ◽

Smooth Surface ◽

Three Dimensional ◽

Rf Magnetron Sputtering ◽

X Ray Diffraction ◽

X Ray ◽

Dimensional Crystal

ABSTRACTUltrathin films of perovskite PbTiO3, 10–100nm thick, were epitaxially grown on miscut (001)SrTiO3 substrate by rf-magnetron sputtering at 600°C. The electron microscope and high resolution x-ray diffraction analysis suggested the evidence of epitaxial growth of (001)PbTiO3/(001)SrTiO3 with three dimensional crystal orientation. The stoichiometric film shows extremely smooth surface with the surface roughness less than 3nm. Deposition on a miscut substrate under stoichiometric conditions is essential to make continuous thin films of single crystal perovskite PbTiO3.

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Smooth surface roughness of silanized CdSe(ZnS) quantum dots

Journal of Colloid and Interface Science ◽

10.1016/j.jcis.2012.10.054 ◽

2013 ◽

Vol 393 ◽

pp. 21-28 ◽

Cited By ~ 2

Author(s):

Jianmin Xu ◽

Chengshan Wang ◽

Jinhai Wang ◽

Qun Huo ◽

Nicholas F. Crawford ◽

...

Keyword(s):

Surface Roughness ◽

Quantum Dots ◽

Smooth Surface

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Snow albedo sensitivity to macroscopic surface roughness using a new ray tracing model

10.5194/tc-2019-179 ◽

2019 ◽

Cited By ~ 1

Author(s):

Fanny Larue ◽

Ghislain Picard ◽

Laurent Arnaud ◽

Inès Ollivier ◽

Clément Delcourt ◽

...

Keyword(s):

Surface Roughness ◽

Smooth Surface ◽

Incident Angle ◽

The Sun ◽

Multiple Reflections ◽

Snow Albedo ◽

Snow Properties ◽

Angle Effect ◽

Effective Angle ◽

The Impact

Abstract. Most models simulating snow albedo assume a flat and smooth surface, neglecting surface roughness. However, the presence of macroscopic roughness leads to a systematic decrease in albedo due to two effects: 1) photons are trapped in concavities (multiple reflection effect) and, 2) when the sun is low, the roughness sides facing the sun experience an overall decrease in the local incident angle relative to a smooth surface, promoting higher absorption, whilst the other sides has weak contributions because of the increased incident angle or because they are shadowed (called the effective angle effect here). This paper aims to quantify the impact of surface roughness on albedo and to assess the respective role of these two effects, with 1) observations over varying amounts of surface roughness, and 2) simulations using the new Rough Surface Ray Tracer (RSRT) model, based on a Monte Carlo method for photon transport calculation. The observations include spectral albedo (400–1050 nm) over manually-created roughness surfaces with multiple geometrical characteristics. Measurements highlight that even a low fraction of surface roughness features (7 % of the surface) causes an albedo decrease of 0.02 at 1000 nm when the solar zenith angle (Өs) is larger than 50°. For higher fractions (13 %, 27 % and 63 %), and when the roughness orientation is perpendicular to the sun, the decrease is of 0.03–0.04 at 700 nm and of 0.06–0.10 at 1000 nm. The impact is 20 % lower when roughness orientation is parallel to the sun. The observations are subsequently compared to RSRT simulations. Accounting for surface roughness improves the model observation agreement by a factor two at 700 nm and 1000 nm (errors of 0.03 and 0.04, respectively), compared to simulations considering a flat smooth surface. The model is used to explore the albedo sensitivity to surface roughness with varying snow properties and illumination conditions. Both multiple reflections and the effective angle effect have more impact with low SSA (

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Heat Transfer in the Turbulent Boundary Layer With a Step Change in Surface Roughness

Volume 4: Heat Transfer; Electric Power; Industrial and Cogeneration ◽

10.1115/91-gt-266 ◽

1991 ◽

Cited By ~ 5

Author(s):

Robert P. Taylor ◽

J. Keith Taylor ◽

M. H. Hosni ◽

Hugh W. Coleman

Keyword(s):

Heat Transfer ◽

Boundary Layer ◽

Surface Roughness ◽

Smooth Surface ◽

Plate Boundary ◽

Step Change ◽

Stanton Number ◽

Test Surface ◽

Temperature Profiles ◽

Boundary Layer Flows

Measurements of Stanton numbers, velocity profiles, temperature profiles, and turbulence intensity profiles are reported for turbulent flat plate boundary layer flows with a step change in surface roughness. The first 0.9 m length of the test surface is roughened with 1.27 mm diameter hemispheres spaced 2 base diameters apart in a staggered array. The remaining 1.5 m length is smooth. The experiments show that the step change from a rough to a smooth surface has a dramatic effect on the convective heat transfer. In many cases, the Stanton number drops below the smooth-wall correlation immediately downstream of the change in roughness. The Stanton number measurements are compared with predictions using the discrete element method with excellent results.

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Effect of Ground Surface Roughness of Tool on Adhesion Characteristics of PVD Coating

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.126-128.609 ◽

2010 ◽

Vol 126-128 ◽

pp. 609-614 ◽

Cited By ~ 4

Author(s):

Masahiro Furuno ◽

Koichi Kitajima ◽

Yousuke Tsukuda ◽

Takeshi Akamatsu

Keyword(s):

Surface Roughness ◽

Smooth Surface ◽

Ground Surface ◽

Scratch Testing ◽

Coating Adhesion ◽

Pvd Coating ◽

Ground Surface Roughness

This study investigated adhesion of coatings on a grinding surface. This was carried out using scratch testing as a function of surface roughness. Three types of coatings were explored: TiAlN, CrSiN and TiSiN. With smaller surface roughness, the coating adhesion showed a tendency to become stronger. In particular, in the case of surface roughness under 2 micrometers for a coating, the coating adhesion was good. Specifically, the CrSiN coating yielded a very smooth surface.

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