Elastohydrodynamic Lubrication Modeling of Hydrodynamic Nanopolishing Process

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Rinku Mittal ◽  
Ramesh K. Singh ◽  
Suhas S. Joshi
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Particle Concentration ◽  
Diamond Turning ◽  
Spindle Speed ◽  
Work Piece ◽  
Process Variables ◽  
Polishing Process ◽  
Mean Pressure ◽  
Abrasive Suspension

Nanopolishing processes are used in medical, industrial, telecommunication, optics, and military fields. Hydrodynamic polishing (HDP) is one of the prominent nanopolishing methods in creating nanopolished surfaces on hard and profiled surfaces, where rigid tool-based methods like diamond turning, grinding, and honing have many limitations. This work is focused on modeling of hydrodynamic polishing method. In this method, a film of abrasive suspension is formed between the work-piece surface and a rotating soft tool, which helps in nanopolishing. The past experimental research gives an insight into the process but the process has not been explicitly modeled. Consequently, besides experimental characterization, a numerical/mathematical model of hydrodynamic polishing process is important. This paper presents a model of the HDP process which takes into account the polishing process variables, such as, contact load, spindle speed, tool and work-piece material properties/geometry, and abrasive suspension properties. The response of the model is the pressure distribution and the abrasive film thickness in the polishing zone. To model the elastohydrodynamic process encountered in HDP, the pressure and the film thickness profiles of lubricated isothermal point contacts have been evaluated using the multilevel multi-integration (MLMI) scheme coded in C programming language. Finally, load, tool stiffness, speed, and particle concentration in the suspension have been implicitly correlated to the surface roughness (SR) to evolve a semi-empirical model for surface roughness as a function of mean film thickness and mean pressure. Empirical models for mean film thickness and mean pressure have also been developed as a function of process variables. These models have been developed from a Taguchi L27 orthogonal array wherein the mean pressure/film thickness values have been determined from the model and the average surface roughness values have been measured experimentally. It has been observed that the load does not affect the surface roughness significantly and mean pressure does not change with the change in abrasive size and spindle speed. Abrasive particle concentration has been found to be the most important parameter and it affects the surface roughness significantly.

An Approach to the Influence of Flotative Abrasive Balls on Polishing Process

2006 ◽  
Vol 532-533 ◽  
pp. 393-396 ◽  
Author(s):  
Yong Dai ◽  
Qian Fa Deng ◽  
Xun Lv ◽  
Ju Long Yuan ◽  
Xun Jie Yu
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Removal Rate ◽  
Great Influence ◽  
Work Piece ◽  
Polishing Process ◽  
Soft Contact ◽  
Ball Diameter ◽  
Experiment Device

Polishing with Flotative Abrasive Balls(FABs) is a kind of soft contact polishing means， and the conventional polishing plate and pad are not needed in this case. The pressure of polishing is the flotage which is the upward force that a fluid exerts on the FABs, but the movement of work piece is similar to that in conventional polishing, the removal rate and quality of polishing is influenced by FAB and its flotage. An experiment device is built up and two kinds of FAB are designed and produced. Some primary experiments are carried out in order to investigate the influences of the size of FABs on the removal rate and surface roughness in polishing with FABs. It is found from the experiments that the grain size and the layers of FAB may have great influence on the removal rate of polishing; the surface roughness is mainly decided by the ball diameter and the layers of FAB. The results of experiments are discussed and analyzed, it indicates that the efficiency and quality depend on flotage and the number of active grains when the velocity of workpiece is assigned.

Effect of Process Parameters on Surface Roughness in the Cloth Wheel Polishing of Stainless Steel

2014 ◽  
Vol 548-549 ◽  
pp. 496-500
Author(s):  
S. Sonthimool ◽  
S. Prombanpong ◽  
Viboon Tangwarodomnukun
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Optimum Condition ◽  
Significant Role ◽  
Process Parameters ◽  
Spindle Speed ◽  
Polishing Process

This paper aims at studying the effect of polishing parameters on surface roughness by using the cloth wheel polishing process. Stainless steel was used as a specimen in this study. The investigation firstly accounted for the comparison between two polishing compounds, and the best one was used to be applied in a set of experiment. The effect of spindle speed, current and polishing time on the surface roughness of stainless steel was examined, and the results showed that polishing time and current played the significant role in degree of roughness. The optimum condition under the range of parameters considered in this work was determined, whose surface roughness was about 0.0466 μm.

Research on ultra-precision polisher for the internal surface of the elbow

2020 ◽  
pp. 002072092094058
Author(s):  
Ping-Ping Qu ◽  
Wei-Na Liu
Keyword(s):  
Finite Element Analysis ◽  
Surface Roughness ◽  
Finite Element ◽  
Simulation Analysis ◽  
Internal Surface ◽  
Work Piece ◽  
Analysis Software ◽  
Polishing Process ◽  
Element Analysis ◽  
Ultra Precision

Aiming at the problem of ultra-precision polishing of the bore surface of the elbow, a new ultra-precision polishing instrument is designed, which is suitable for the inner hole finishing and finishing of the elbow, and is placed in the cavity of the work piece, the flexible line connecting spherically spraying ultra-precision polishing instrument. And the simulation analysis of the polishing process in the elbow is carried out by ANSYS 11.0 finite element analysis software. It is verified that the polishing instrument can finish the ultra-precision polishing of the internal surface of the elbow, and achieve the purpose of the internal surface roughness reduction.

A Study on the Influence of Milling Parameters on the Properties of TC18 Titanium Alloy

2020 ◽  
Vol 12 (5) ◽  
pp. 707-714
Author(s):  
Chang-Ming Zhang ◽  
An-Le Mu ◽  
Yong-Xin Wang ◽  
Qi Shen ◽  
Hui Zhang
Keyword(s):  
Surface Roughness ◽  
Titanium Alloy ◽  
High Speed ◽  
Surface Hardness ◽  
Processing Parameters ◽  
Spindle Speed ◽  
Orthogonal Experimental Design ◽  
Work Piece ◽  
Milling Force ◽  
Metal Microstructure

Based on the orthogonal experimental design, the effect mechanism of different processing parameters on the surface microhardness and metal microstructure of TC18 titanium is studied. Meanwhile, the variation law of milling force and surface roughness of TC18 titanium alloy during high-speed milling is obtained. The results show that the milling depth has the greatest influence on the milling force under down-milling. Meanwhile, the milling depth and spindle speed have the greatest influence on the milling force in up-milling, which with the increase of milling depth and with the increase of spindle speed and downward trend. The greatest influence of surface roughness is the milling depth, and the surface roughness decreases with the increasing of milling depth. After milling complete, the surface hardness of TC18 titanium alloy work piece decreases. With the surface depth increases to 0.01 mm, the hardness is slightly higher than the matrix hardness. The microstructure of TC18 matrix is mainly β phase by observing the metallographic structure. The equiaxed α phase grows after milling.

Polishing Process of Ceramic Tiles - Variation of Contact Pressure

2013 ◽  
Vol 769 ◽  
pp. 124-130 ◽  
Author(s):  
Anatolij Olenburg ◽  
Marcelo Reami Salati ◽  
Filipe Sant´Ana ◽  
Fabio Jose Pinhero Sousa
Keyword(s):  
Surface Roughness ◽  
Contact Pressure ◽  
Removal Rate ◽  
Cement Matrix ◽  
Work Piece ◽  
Abrasive Tool ◽  
Ceramic Tiles ◽  
Polishing Process ◽  
Measuring Machine

The contact pressure is one of the most important parameter in the industrial polishing process of ceramic tiles. The contact pressure is asically a function of the elasticity moduli of both tile and abrasive tool, the applied load, and also the curvature of the abrasive tool. Due to the wear, this curvature decreases during the polishing process, causing an increase in the contact pressure. The purpose of this work is to research the influence of contact pressure on the evolution of gloss and roughness of the polished ceramic tiles and to improve the quality of generated surface. The variation of curvature was replaced with the direct increment of three different normal forces onto the abrasive tool. It is known from literature that for fine abrasive grits higher tool loads increase gloss gain and decrease roughness. However, there are not many works that research the whole sequence of abrasives for different loads and compare the quality of the final surface. Polishing tests on a laboratory scale CNC-Tribometer have been used to study the industrial polishing process for unglazed porcelain ceramic tiles. Tests were carried out for three different tool loads with a sequence of progressively smaller silicon carbide abrasive particles embedded in a magnesia cement matrix. Tile surface quality was evaluated by roughness and optical gloss. The removed work piece material and the used abrasive were measured with a coordinate measuring machine. The distribution of gloss and roughness of the tile was measured before and during the experiments until a saturation of gloss and roughness for each grit number was achieved, respectively. The topography of the tile was measured before and after the polishing process with particularly grit number. The used abrasives show a general trend of increasing gloss and decreasing roughness during the process. The coarse abrasives caused the major effect on surface roughness and almost no effect on gloss. In opposite finer abrasives caused the major gloss enhancement and almost no effect on surface roughness. The results show the evolution of roughness and gloss for each load as a function of abrasive grit number and polishing time, as well as the material removal rate for each grit number and load.

On the Mean Reynolds Equation in the Presence of Surface Roughness: Squeeze-Film Bearing

1981 ◽  
Vol 48 (4) ◽  
pp. 717-720 ◽  
Author(s):  
N. Phan-Thien
Keyword(s):  
Surface Roughness ◽  
Flow Field ◽  
Film Thickness ◽  
Reynolds Equation ◽  
Squeeze Film ◽  
Two Dimensional ◽  
Homogeneous Surface ◽  
Parallel Surface ◽  
Mean Pressure ◽  
The Mean

The mean Reynolds equation in the presence of surface roughness is derived using the techniques developed by Keller. This mean equation is nonlocal in the sense that the mean pressure at all points in the flow field has some effect on the mean pressure at any particular point. The performance of a two-dimensional squeeze film bearing with homogeneous surface roughness is considered next showing that the load is enhanced by a factor of 1 + ε2a2S/h2, where εa is the amplitude of the roughness, h is the film thickness, and S varies between −3 〈m2〉, for parallel surface roughness, to 6 〈m2〉 for transverse surface roughness. Here, the bearing surfaces are described by εam1 and h + εam2 and m = m2 − m1.

A new method for quantifying the blocking of coated paperboard

TAPPI Journal ◽  
2010 ◽  
Vol 9 (5) ◽  
pp. 29-35 ◽  
Author(s):  
PAULINE SKILLINGTON ◽  
YOLANDE R. SCHOEMAN ◽  
VALESKA CLOETE ◽  
PATRICE C. HARTMANN
Keyword(s):  
Surface Roughness ◽  
Fatty Acid ◽  
Surface Energy ◽  
Film Thickness ◽  
External Factors ◽  
Additive Concentration ◽  
Pressure Surface ◽  
Fatty Acid Amides ◽  
Coated Surfaces ◽  
Definite Period

Blocking is undesired adhesion between two surfaces when subjected to pressure and temperature constraints. Blocking between two coated paperboards in contact with each other may be caused by inter-diffusion, adsorption, or electrostatic forces occurring between the respective coating surfaces. These interactions are influenced by factors such as the temperature, pressure, surface roughness, and surface energy. Blocking potentially can be reduced by adjusting these factors, or by using antiblocking additives such as talc, amorphous silica, fatty acid amides, or polymeric waxes. We developed a method of quantifying blocking using a rheometer. Coated surfaces were put in contact with each other with controlled pressure and temperature for a definite period. We then measured the work necessary to pull the two surfaces apart. This was a reproducible way to accurately quantify blocking. The method was applied to determine the effect external factors have on the blocking tendency of coated paperboards, i.e., antiblocking additive concentration, film thickness, temperature, and humidity.

Analysis of Surface Roughness and Waviness During Diamond Turning of Polycarbonate

2012 ◽  
Vol 2 (6) ◽  
pp. 268-270 ◽  
Author(s):  
Harinderpal Singh Harinderpal Singh ◽  
◽  
Rahul O vaishya ◽  
Karanvir Sing ◽  
Vinod Mishra ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Diamond Turning

Prediction of Surface Roughness and Optimization of Cutting Parameters in CNC Turning of Rotational Features

2020 ◽  
Vol 38 (8A) ◽  
pp. 1143-1153
Author(s):  
Yousif K. Shounia ◽  
Tahseen F. Abbas ◽  
Raed R. Shwaish
Keyword(s):  
Surface Roughness ◽  
Linear Regression ◽  
Regression Model ◽  
Linear Regression Model ◽  
Feed Rate ◽  
Cutting Parameters ◽  
Spindle Speed ◽  
Depth Of Cut ◽  
Non Linear ◽  
Optimization Of Cutting Parameters

This research presents a model for prediction surface roughness in terms of process parameters in turning aluminum alloy 1200. The geometry to be machined has four rotational features: straight, taper, convex and concave, while a design of experiments was created through the Taguchi L25 orthogonal array experiments in minitab17 three factors with five Levels depth of cut (0.04, 0.06, 0.08, 0.10 and 0.12) mm, spindle speed (1200, 1400, 1600, 1800 and 2000) r.p.m and feed rate (60, 70, 80, 90 and 100) mm/min. A multiple non-linear regression model has been used which is a set of statistical extrapolation processes to estimate the relationships input variables and output which the surface roughness which prediction outside the range of the data. According to the non-linear regression model, the optimum surface roughness can be obtained at 1800 rpm of spindle speed, feed-rate of 80 mm/min and depth of cut 0.04 mm then the best surface roughness comes out to be 0.04 μm at tapper feature at depth of cut 0.01 mm and same spindle speed and feed rate pervious which gives the error of 3.23% at evolution equation.

scholarly journals Ultrasonic dispersion method used in glass polishing experiment

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110118
Author(s):  
Zenan Chu ◽  
Tao Wang ◽  
Qiang He ◽  
Kai Zhao
Keyword(s):  
Surface Roughness ◽  
Rare Earth ◽  
Surface Morphology ◽  
Ultrasonic Method ◽  
Average Surface Roughness ◽  
Polishing Process ◽  
Ultrasonic Dispersion ◽  
Processing Efficiency ◽  
Average Surface ◽  
Evaluation Indexes

To solve the problems of low processing efficiency and poor glass surface quality when using rare earth polishing powder to grind super-hard K9 glass. The potential, phase structure, surface morphology, and particle size distribution of the nano-rare earth polishing powder were characterized. Compare the evaluation indexes such as polishing efficiency, surface morphology, and contact angle after the polishing process is changed. The results of the comparative study show that the average surface roughness of the glass after heating ultrasonic polishing process is 0.9064 nm, the polishing rate reaches 0.748 μm/min, the average surface roughness of the glass without heating ultrasonic polishing process is 1.3175 nm, and the polishing rate reaches 0.586 μm/min, the ultrasonic assisted polishing process is superior to the conventional polishing process. The heating ultrasonic method provides experimental basis for precise and rapid processing.

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