On the Lapping Mechanism of Optical Fiber End-Surfaces Using Fixed Diamond Abrasive Films

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
JiAn Duan ◽  
DeFu Liu
Keyword(s):  
Particle Size ◽  
Optical Fiber ◽  
Material Removal ◽  
Abrasive Particle ◽  
Particle Sizes ◽  
Material Removal Mechanisms ◽  
Ductile Mode ◽  
Deformed Layer ◽  
Diamond Abrasive ◽  
Scanning Electron

The purpose of this paper is to reveal material removal mechanisms of optical fiber end-surface in lapping processes. The lapping process experiments are conducted using fixed diamond abrasive lapping films with various particle sizes of 6 μm, 3 μm, 1 μm, and 0.5 μm. The micrographs of the optical fiber end-surfaces are observed using a scanning electron microscope. The experimental results show that there exist three material removal modes in the lapping processes: brittle fracture mode, semibrittle and semiductile mode, and ductile mode. These modes are mainly controlled by abrasive particle size, and there appears a brittle-ductile transition’s critical point when lapping films with a particle size of 3 μm are used to lap optical fiber end-surfaces. An interpretation is proposed for the formation mechanism of the plastic deformed layer on the optical fiber end-surfaces.

Effects of Viscosity, Particle Size, and Particle Shape on Erosion in Gas and Liquid Flows

2011 ◽  
Author(s):  
Risa Okita ◽  
Yongli Zhang ◽  
Brenton S. McLaury ◽  
Siamack A. Shirazi ◽  
Edmund F. Rybicki
Keyword(s):  
Particle Size ◽  
Stainless Steel ◽  
Solid Particle ◽  
Abrasive Particle ◽  
Glass Beads ◽  
Solid Particle Erosion ◽  
Particle Sizes ◽  
Particle Erosion ◽  
Particle Velocities ◽  
Liquid Flows

Although solid particle erosion has been examined extensively in the literature for dry gas and vacuum conditions, several parameters affecting solid particle erosion in liquids are not fully understood and need additional investigation. In this investigation, erosion ratios of two materials have been measured in gas and also in liquids with various liquid viscosities and abrasive particle sizes and shapes. Solid particle erosion ratios for aluminum 6061-T6 and 316 stainless steel have been measured for a direct impingement flow condition using a submerged jet geometry, with liquid viscosities of 1, 10, 25, and 50 cP. Sharp and rounded sand particles with average sizes of 20, 150, and 300 μm, as well as spherical glass beads with average sizes of 50, 150 and 350 μm, were used as abrasives. To make comparisons of erosion in gas and liquids, erosion ratios of the same materials in air were measured for sands and glass beads with the particle sizes of 150 and 300 μm. Based on these erosion measurements in gas and liquids, several important observations were made: (1) Particle size did not affect the erosion magnitude for gas while it did for viscous liquids. (2) Although aluminum and stainless steel have significant differences in hardness and material characteristics, the mass losses of these materials were nearly the same for the same mass of impacting particles in both liquid and gas. (3) The most important observation from these erosion tests is that the shape of the particles did not significantly affect the trend of erosion results as liquid viscosity varied. This has an important implication on particle trajectory modeling where it is generally assumed that particles are spherical in shape. Additionally, the particle velocities measured with the Laser Doppler Velocimetry (LDV) near the wall were incorporated into the erosion equations to predict the erosion ratio in liquid for each test condition. The calculated erosion ratios are compared to the measured erosion ratios for the liquid case. The calculated results agree with the trend of the experimental data.

Effect of Abrasive Particle Size on Lapping of Sapphire Wafer by Fixed Abrasive Pad

2018 ◽  
Vol 764 ◽  
pp. 106-114
Author(s):  
Jian Bin Wang ◽  
Zhen Li ◽  
Yong Wei Zhu ◽  
Ben Chi Jiang ◽  
Pei Cheng Shi
Keyword(s):  
Particle Size ◽  
Penetration Depth ◽  
Material Removal ◽  
Removal Rate ◽  
Abrasive Particle ◽  
Work Piece ◽  
Average Surface Roughness ◽  
Sapphire Wafer ◽  
Fixed Abrasive Pad ◽  
Fixed Abrasive

The choice of abrasive particle size is crucial to improve the lapping efficiency and surface quality in lapping of sapphire wafer by fixed abrasive (FA) pad. A model for the penetration depth of a single abrasive is developed with fixed abrasive pad. A serious of lapping tests were carried out using FA pads embedded with different size of diamond particles to verify the validity of the developed model. Results show that the penetration depth of abrasive is related not only to the particle size, but to the hardness ratio of the work-piece to the pad as well. The material removal rate of sapphire is proportional to the square of abrasive particle size, while the average surface roughness is proportional to the abrasive particle size.

An Experimental Study on the Effects of Abrasive Particle Sizes on Polishing Phenomena

2006 ◽  
Vol 505-507 ◽  
pp. 301-306
Author(s):  
Yeau Ren Jeng ◽  
Pay Yau Huang
Keyword(s):  
Experimental Study ◽  
Particle Size ◽  
Theoretical Model ◽  
Test Bench ◽  
Abrasive Particle ◽  
Theoretical Data ◽  
Measurement Technology ◽  
Particle Sizes ◽  
Polishing Process

The effects of abrasive particle size on polishing phenomena during wafer planarization are investigated using a high precision polishing process test bench with in-situ measurement technology. The present experimental results are found to be comported with the experimental and theoretical data published previously. The current experimental outcomes can help to understand the polishing mechanism and develop the relating theoretical model.

Gas Desorption of Different Particle Size Coal under the Effect of Electromagnetic Radiation

2014 ◽  
Vol 953-954 ◽  
pp. 1205-1209
Author(s):  
De Zhu Cheng ◽  
Ai Ling Du ◽  
Shan Chao Jiang ◽  
Ai Qin Du
Keyword(s):  
Particle Size ◽  
Optical Fiber ◽  
Electromagnetic Radiation ◽  
Coal Particle ◽  
Optical Fiber Sensor ◽  
Gas Content ◽  
Fiber Sensor ◽  
Particle Sizes ◽  
Coal Gas ◽  
Gas Desorption

Many factors can influence coal gas desorption. In this paper, the impact of coal particle size on coal gas desorption under the effect of microwave radiation was mainly studied. Infrared (IR) spectroscopy and optical fiber sensor were used to on-line detect and the qualitative and quantitative analysis of the desorbed gas. The analysis results of the infrared spectrogram showed that under the effect of electromagnetic radiation (2450Hz, 1.5μT), different particle sizes of coal sample could desorb gas which contained carbon dioxide, carbon monoxide and methane. The comparison of gas content detected by optical fiber sensor indicated that coal particle sizes had a significant influence on coal gas desorption. When coal particle was between 100 and 200 meshes, the gas content reached up to 27.58 m3/t.

scholarly journals The Influence of Starch Modification with Amylosucrase Treatment on Morphological Features

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1409
Author(s):  
Hyeyoung Lee ◽  
Inmyoung Park
Keyword(s):  
Particle Size ◽  
Cross Section ◽  
Resistant Starch ◽  
Flat Surface ◽  
Particle Sizes ◽  
Particle Size Analyzer ◽  
The Mean ◽  
Waxy Corn ◽  
Slowly Digestible Starch ◽  
Scanning Electron

Amylosucrase (AS) is a starch-modifying enzyme from Neisseria polysaccharea used to produce low-glycemic starches such as slowly digestible starch (SDS) and resistant starch (RS). The morphology of native, control, and AS-modified waxy corn starches (230 and 460 U) was examined using a particle size analyzer and field-emission scanning electron microscopy (FE-SEM). AS modification of the starch elongated the glucose and resulted in higher SDS and RS contents. The mean particle sizes of the control, 230 U-AS-, and 460 U-AS-treated starches were 56.6 µm, 128.0 µm, and 176.5 μm, respectively. The surface of the 460 U-AS-treated starch was entirely porous and coral-like, while the 230 U-AS-treated starch had a partial dense and flat surface which did not react with AS. FE-SEM of the granule cross section confirmed that the center contained a dense and flat region without any evidence of AS reaction to either of the AS-treated starches. It was assumed that the particle size and porous and sponge-like particle features might be related to the SDS and RS fractions.

Material Removal Mechanisms of Oxide and Nitride CMP with Ceria and Silica-Based Slurries - Analysis of Slurry Particles Pre- and Post-Dielectric CMP

2004 ◽  
Vol 816 ◽  
Author(s):  
Naga Chandrasekaran
Keyword(s):  
Material Removal ◽  
Surface Composition ◽  
Removal Rate ◽  
Abrasive Particle ◽  
Surface Hardness ◽  
Organic Coating ◽  
Material Removal Mechanisms ◽  
Removal Mechanisms ◽  
The Difference ◽  
Oxide Removal

AbstractThe effect of CMP process parameters (pressure and pad hardness) on the ceria and silica abrasive particle-size distribution (PSD), morphology, and surface composition when polishing oxide and nitride surfaces was investigated in detail. The PSD was observed to shift post-CMP, with ceria and silica exhibiting a decrease and increase, respectively, in the number of particles towards the tail end of the distribution. The shift in ceria PSD was observed to increase as pad hardness increased. An increase in polish pressure and work surface hardness resulted in an equivalent shift in the PSD when polished on a soft pad. The inclusion of an additive reduced the oxide removal rate, and the abrasive particles exhibited the presence of a thin organic coating on the surface. The difference in material removal mechanisms and selectivity when polishing oxide and nitride with ceria and silica-based slurries was also investigated in detail.

Effects of Nano-scale Colloidal Abrasive Particle Size on SiO2 by Chemical Mechanical Polishing

2001 ◽  
Vol 671 ◽  
Author(s):  
Chunhong Zhou ◽  
Lei Shan ◽  
S.H. Ng ◽  
Robert Hight ◽  
Andrew. J. Paszkowski ◽  
...  
Keyword(s):  
Particle Size ◽  
Material Removal Rate ◽  
Surface Finish ◽  
Material Removal ◽  
Removal Rate ◽  
Abrasive Particle ◽  
Single Crystal Silicon ◽  
Weight Percent ◽  
Crystal Silicon ◽  
P Type

ABSTRACTThis paper reports on the effect of colloidal abrasive particle size in the polishing of thermally grown silicon dioxide on 100mm diameter, P-type, (100), single crystal silicon wafers. The abrasive particle sizes were varied in six (6) slurries with pH values of 10.97 ± 0.08. The abrasive sizes were 10, 20, 50, 80, 110 and 140nm in diameter, and the slurry contained 30 weight percent abrasives. The experimental results indicate that the material removal rate (MRR) varies with the volume of the particle size. Results also confirm that there exists an optimum abrasive particle size with respect to material removal rate and surface finish. For a pad surface roughness of 5.2μm (Ra), the slurry containing 80nm particles resulted in the highest material removal rate and best surface finish. A nano-film model based on the pad roughness is used to explain the results.

Micro Ultrasonic Machining Using Oil Based Abrasive Slurry

2008 ◽  
Author(s):  
Murali M. Sundaram ◽  
Sreenidhi Cherku ◽  
K. P. Rajurkar
Keyword(s):  
Particle Size ◽  
Material Removal Rate ◽  
Surface Finish ◽  
Material Removal ◽  
Removal Rate ◽  
Abrasive Particle ◽  
High Wear Resistance ◽  
Ultrasonic Machining ◽  
Influence Of Process Parameters ◽  
Slurry Concentration

Advanced engineering materials posses excellent properties such as high wear resistance, and inertness to corrosion and chemical reactions. Since these materials are usually hard, brittle, chemically inert, and electrically nonconductive, they pose serious machinability challenges. Micro ultrasonic machining (Micro USM) is an emerging method for the micromachining of hard and brittle materials without any thermal damage. This paper presents the results of micro ultrasonic machining using oil based abrasive slurry. Details of the in-house built experimental setup used to conduct the experiments are explained. The influence of process parameters such as slurry medium, slurry concentration, and abrasive particle size on the performance of micro USM are reported. It was noticed that the evidence of three body material removal mechanism is predominant for micro USM using oil based slurry. In general, the material removal rate increases with the increase in the abrasive particle size for both aqueous abrasive slurry and oil based abrasive slurry. Further, material removal rate is consistently higher for experiments conducted with aqueous abrasive slurry medium. On the other hand, it is noticed that the oil based slurry medium provides better surface finish. It is also noticed that the smaller abrasive grains provide better surface finish for both aqueous, and oil based abrasive slurry mediums. Role of slurry concentration is ambiguous, as no clear trend of its effect of on process performance is evident in the available experimental results.

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