Analysis on the Micro Surface Morphology of Aged Oil-Paper Used in Power Transformer

2013 ◽  
Vol 860-863 ◽  
pp. 894-898
Author(s):  
Chao Tang ◽  
Sheng Li Dai ◽  
Jiao Li
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Power Transformer ◽  
Roughness Parameter ◽  
Fiber Surface ◽  
Thermal Ageing ◽  
Molecular Arrangement ◽  
Atomic Force ◽  
Roughness Analysis ◽  
Mesh Structures

In order to analyze the ageing mechanism of oil-paper, the Atomic Force Microscope (AFM), which is one of the important instruments in nanometer area, was used in this paper for the analysis of the micro surface morphology, and a 3-D surface roughness analysis on the AFM image was presented. The AFM figures indicates that the molecular arrangement of the initial cellulose paper is close and ordered, some of the hexagonal mesh structures of the D-glucopyranose units were broken down after 100 days accelerated thermal ageing. The roughness analysis indicates that he fiber surface roughness parameter Sa increases with the deepening of ageing degree. Special attention should be paid on the increase in the surface roughness of insulation paper, as it will aggravate the oil streaming electrification when the paper is applied to the power transformers.

Thermal-ageing characteristics of dry-type transformer epoxy composite insulation

2020 ◽  
Vol 32 (7) ◽  
pp. 741-752
Author(s):  
Yongqiang Wang ◽  
Changhui Feng ◽  
Ruoyu Fei ◽  
Yu Luo
Keyword(s):  
Surface Roughness ◽  
Dielectric Constant ◽  
Surface Morphology ◽  
Epoxy Resin ◽  
Degradation Mechanism ◽  
Three Dimensional ◽  
Thermal Ageing ◽  
Ageing Process ◽  
Complex Dielectric Constant ◽  
Significant Difference

To study the ageing characteristics of epoxy resin composite insulation in dry-type transformers in high-temperature environments, glass fibre-reinforced epoxy resin samples were placed in a hot air ageing environment at 130°C for testing. Dielectric properties, partial discharge (PD), microscopic morphology, three-dimensional morphology and Fourier transform infrared spectroscopy of aged samples were periodically tested. The results show that during the ageing process, the change in the surface morphology of the sample leads to an overall upward trend in surface roughness, and the older the sample, the faster the surface roughness increases; changes in the surface morphology and three-dimensional morphology of the material constitute the basis for judging the condition of the insulating surface and the state of ageing development. Microcracks are the direct cause of debonding of glass fibres and epoxy matrix. Degradation of the sample during the ageing process generates many free radicals, which enhances the polarisation ability of the sample and increases both the dielectric constant and the dielectric loss factor. The real part of the complex dielectric constant is more sensitive to the ageing response of the sample. The older the sample, the greater the effect on the results of the dielectric spectrum test. Since the aged sample generates more hot electrons during the PD process and makes it easier to inject electrons into the material, the PD of the sample is rendered more intense by thermal ageing. There is a significant difference between the degradation mechanism of the thermal ageing and PD. The samples subjected to PD after thermal ageing produce new groups, and the degradation of the samples is more severe than that caused by thermal ageing, or PD, alone.

Surface roughness analysis of ceramic bracket slots using atomic force microscope

2010 ◽  
Vol 40 (5) ◽  
pp. 294 ◽  
Author(s):  
Ki-Ho Park ◽  
Hyun-Joo Yoon ◽  
Su-Jung Kim ◽  
Gi-Ja Lee ◽  
Hun-Kuk Park ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscope ◽  
Atomic Force ◽  
Roughness Analysis ◽  
Ceramic Bracket

Growth of Germanium on Porous Silicon (001)

1996 ◽  
Vol 452 ◽  
Author(s):  
W. H. Thompson ◽  
Z. Yamani ◽  
H. M. Nayfeh ◽  
M.-A. Hasan ◽  
J. E. Greene ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Porous Silicon ◽  
Molecular Beam Epitaxy ◽  
Surface Morphology ◽  
Molecular Beam ◽  
Porous Si ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nm Range

AbstractThe surface morphology of Ge grown on Si (001) and porous Si(001) by molecular beam epitaxy at 380 °C is examined using atomic force microscopy (AFM). For layer thicknesses of 30 nm, the surface shows islanding while still maintaining some of the underlying roughness of the surface of porous Si. For thicknesses in the 100 nm range, the surface roughness is not visible, but the islanding persists. Unlike the case of silicon where islands tend to merge and nearly disappear as the thickness of the deposited layer rises, we observe on the porous layer the persistence of the islands with no merging even for macroscopic thicknesses as large as 0.73 microns.

Mitigation of BPD by Pre-Epigrowth High Temperature Substrate Annealing

2016 ◽  
Vol 858 ◽  
pp. 233-236 ◽  
Author(s):  
Nadeemullah A. Mahadik ◽  
Robert E. Stahlbush ◽  
Eugene A. Imhoff ◽  
M.J. Tadjer ◽  
G.E. Ruland ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
High Temperature ◽  
Surface Morphology ◽  
Substrate Surface ◽  
High Temperature Annealing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Substrate Annealing ◽  
Edge Dislocations

Basal Plane Dislocations (BPD) intersecting the SiC substrate surface were converted to threading edge dislocations (TED) by high temperature annealing of the substrates in the temperature range of 1750 °C – 1950 °C. Successively, epitaxial growth on annealed as well as non-annealed samples was performed, concurrently, to investigate the effect of the substrate annealing on BPD mitigation in the epilayers. For the 1950 °C/10min anneal, a 3x reduction in BPD density was observed. Additionally, surface roughness measured using atomic force microscopy revealed no degradation in surface morphology of the grown epilayers after annealing.

Surface Morphology, Crystal Orientation and Scratch Properties of Au/NiCr/Ta Multi-Layered Metallic Films

2007 ◽  
Vol 353-358 ◽  
pp. 1863-1866
Author(s):  
Wu Tang ◽  
Long Jiang Deng ◽  
Ke Wei Xu ◽  
Jian Lu
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Substrate Temperature ◽  
Crystal Orientation ◽  
Scratch Test ◽  
Test Method ◽  
Metallic Films ◽  
Force Microscopy ◽  
Atomic Force ◽  
Friction Mode

The crystal orientation, surface morphology, surface roughness and scratch properties of Au/NiCr/Ta multi-layered metallic films was examined by X-ray diffraction (XRD), atomic force microscopy (AFM) and a scratch test method, respectively. It was clarified that the surface morphology and surface roughness depend on the substrate temperature. The surface roughness decreases from 4.259nm to 2.935nm when substrate temperature changed from 100°C to 180°C, and then increases when substrate temperature above 180°C. The XRD revealed that there are only Au diffraction peaks with highly textured having a Au-(111) or a mixture of Au-(111) and Au-(200) orientation. The micro-scratch test reveals that both modes can be used for conventionally critical load determination, but the friction mode can additionally reflect the changes at different metallic film layers, the critical characteristic load was not sensitive to substrate temperature.

scholarly journals Comparative Study of Surface Roughness of Tungsten and Alumina co-sputtered on Stainless Steel and Copper substrates

2020 ◽  
Author(s):  
Naveen Ankegowda ◽  
G V Naveen Prakash ◽  
K Ravi ◽  
Khalid Imran ◽  
K B Vinay ◽  
...  
Keyword(s):  
Thin Film ◽  
Surface Roughness ◽  
Comparative Study ◽  
Input Parameter ◽  
Argon Atmosphere ◽  
Average Surface Roughness ◽  
Average Surface ◽  
Atomic Force ◽  
Roughness Analysis ◽  
Cu Substrates

Abstract A comparative study of the effect of co-sputtering specifically mag­netron sputtering process input factors on surface roughness of W and Al2O3 thin film developed on the SS304 and Copper(Cu) substrates in the argon atmosphere. The input parameters have been varied based on the Design of Experiments specifically Center Composite Design experimental plan. Atomic Force microscope has been used to determine the average surface roughness in nanometer of all the samples as per experimental combinations. By using ANOVA method, the effect of factors on roughness and regression model have been developed, which express degree to input parameter can effect on the surface roughness. Analysis of surface roughness of W and Al2O3 thin film developed above said different substrates have been presented.

MICROSTRUCTURE EVOLUTION OF GOLD ATOMIC AGGREGATES FABRICATED ON SILICONE OIL SURFACE

2015 ◽  
Vol 22 (05) ◽  
pp. 1550066 ◽  
Author(s):  
YUANXIN FENG ◽  
CHUHANG ZHANG
Keyword(s):  
Surface Roughness ◽  
Microstructure Evolution ◽  
Au Nanoparticles ◽  
Silicone Oil ◽  
Force Microscopy ◽  
Atomic Force ◽  
Roughness Analysis ◽  
Shadowing Effect ◽  
The Mean ◽  
Afm Observation

Gold atomic aggregates are fabricated by vapor-depositing Au atoms onto a silicone oil surface and the microstructure evolution is investigated by atomic force microscopy (AFM) observation. It is found that the Au aggregates are composed of Au circular nanoparticles with diameter around 45 nm, which is independent with the nominal film thickness d. As d increases from 1 nm to 15 nm, the height of the nanoparticles increases from 15 nm to 25 nm, indicating the geometric shape of the Au nanoparticles evolves from plateau to spherical. Furthermore, the roughness analysis shows that the mean surface roughness increases linearly with d in the range of 1 nm–15 nm, which is quite different from the findings in Ag system. The anomalous microstructure evolution of Au aggregates suggests that the growth of Au aggregates may be dominated by the shadowing effect.

Investigating the Effect of Process Parameters in Incremental Sheet Forming Process

2021 ◽  
pp. 24-36
Author(s):  
Manish Oraon ◽  
Manish Kumar Roy ◽  
Vinay Sharma
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Sheet Forming ◽  
Incremental Sheet Forming ◽  
Forming Process ◽  
Batch Production ◽  
Force Microscopy ◽  
Atomic Force ◽  
Roughness Analysis ◽  
Step Down

Incremental sheet forming (ISF) is an emerging technique of sheet metal working that comes into the picture in the last two decades. The ISF involved the forming of shapes without using the dedicated dies. ISF is suitable for customized products, rapid prototyping, and low batch production. The study aims to investigate the effect of process parameters on the surface roughness. The experiments are conducted on aluminum AA3003-O grade with six parameters, and the trials are performed according to the design of experiment (DOE). The atomic force microscopy (AFM) technique is used for measuring the surface roughness. Analysis of variance (ANOVA) is used for analyzing the effect of process parameters in ISF. The result shows that the step-down size, feed rate of the tool, and wall angle are significant process parameter and their contributions for ISF are 85.86%, 1.12%, and 12.29%, respectively.

Effect of Borax Content on Composition and Microstructure of Boride Layer by Electrodeposition

2011 ◽  
Vol 179-180 ◽  
pp. 508-512 ◽  
Author(s):  
Hai Li Yang ◽  
Ning He ◽  
Guo Zhang Tang ◽  
Yun Gang Li ◽  
Yu Zhu Zhang
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Glow Discharge ◽  
Surface Morphology ◽  
Molten Salts ◽  
Boride Layer ◽  
Silicon Steel ◽  
Force Microscopy ◽  
Atomic Force ◽  
Compositional Depth Profile

Boronizing of silicon steel is performed by electrodeposition in KCl-NaCl-NaF-Na2B4O710H2O molten salts with different amounts of borax. The effect of borax content on composition and microstructure of boride layer is studied. The compositional depth profile of boride layer is measured using the glow discharge spectrometry (GDS) and the depth from the surface to the substrate is taken as the layer thickness. The surface morphology is studied by atomic force microscopy (AFM). It is found that the thickness of the boride layer reached maximum values when the borax content is 0.05mol. The roughness decreases with raising borax content from 0.01 to 0.05mol while the further increase of borax content from 0.05 to 0.1mol results in increase of roughness. The boride layer formed at borax content 0.05 mol shows smallest values of surface roughness.

Pt Hillock Formation and Decay

1994 ◽  
Vol 361 ◽  
Author(s):  
Scott R. Summerfelt ◽  
Dave Kotecki ◽  
Angus Kingon ◽  
H.N. Al-Shareef
Keyword(s):  
Surface Roughness ◽  
Electron Beam Evaporation ◽  
Dielectric Thickness ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Hillock Formation ◽  
Roughness Analysis ◽  
High Dielectric

ABSTRACTThe formation of Pt hillocks during high temperature processing is a problem when using Pt as a bottom electrode for high dielectric constant materials. The hillock height is frequently larger than the dielectric thickness, degrading the leakage current of the device. In this work, Pt was deposited by electron beam evaporation on in-situ formed 40 nm ZrO2 coated SiO2 / Si substrates. The samples were then annealed at temperatures between 400°C and 700°C for times ranging from 2 min to 40 min. The surface roughness was measured by atomic force microscopy (AFM). The surface was characterized using Ra, RMS and Zmax over 5 μm × 5μm regions. Zmax is sensitive to hillock formation and Ra is sensitive to changes in general surface roughness. Analysis of Zmax indicates that 100 nm Pt / ZrO2 deposited at 315°C forms hillocks above 450°C during initial heatup. Subsequently, the hillocks decay for temperatures of 600°C and above such that they are almost gone after a 30 min air anneal. In-situ wafer stress measurements of Pt / ZrO2 were performed in O2 at temperatures up to 650°C. The Pt relaxes above 500°C in O2.

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