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B. Anand Ronald, L. Vijayaraghavan, R. Krishnamurthy
Evaluation of surface quality of ground Al/SiCp metal matrix composites

A detailed study on grinding of metal matrix composites with resin bonded and plated diamond wheels have been carried out to evaluate the surface quality. The measurands namely grinding force and temperature during grinding were monitored online. Surface finish was measured offline using a stylus based instrument and the ground surface was observed through Scanning Electron Microscope (SEM) for process status evaluation. From the study, it was found that better surface quality (based on surface finish and SEM of machined surface) was achievable with resin bonded wheel as compared to electroplated wheel. Also electroplated wheel experiences higher order force.

B. Ramamoorthy, B. Dhanasekar
Assessment of surface roughness of moving surfaces

Computer vision with digital image processing is one of the widely used research tools and finds many applications in various branches of engineering. In a manufacturing environment, it is used for many applications such as inspection, recognition and navigation. In this work, the objective is to evaluate the surface roughness of uniformly moving machined surface using machine vision technique. Basically, the problem in estimating the roughness of moving surfaces based on their images is blurring. It is important that blurred image has to be corrected for its distortion and restored before any further analysis. This image restoration needs to be resolved before proceeding to the evaluation of roughness of such surfaces. In this work, geometric distortion removal technique is used for image restoration. Then, the quantification of surface roughness using these improved quality images is carried out using various parameters such as spatial frequency, arithmetic mean value and standard deviation. Group method of data handling (GMDH) technique was used to compare the optical roughness parameters calculated using the digital surface images and the widely used mechanical stylus instrument values. An analysis based on the comparison to understand the validity of the present approach of estimation of surface finish based on the digitally processed images for implementation in practice, is presented in this paper.

R. Raghunandan, P. V. Rao
An approach to estimate the sample size based on surface roughness for flatness error measurement using CMM

The present day manufacturing environment requires accurate inspection of both dimension and form while minimizing the cost and time of inspection. Flatness error is an important form tolerance that is used for the control of machined surfaces. The evaluation of flatness error depends on a variety of factors such as selection of sampling plan - sample size and sample point locations, the method of evaluating the form error and the nature of the manufactured surfaces amongst which the sample size is very critical. In most cases the sample size is decided based on the experience of the inspector or is randomly selected which may not be the ideal methods if a high degree of accuracy is required for the evaluation of the flatness error. Investigations carried out reveal that the surface roughness influences the accuracy of inspection and can be used as a parameter for determining an initial sample size for the determination of flatness error. The experimentation involved the inspection on surfaces with different roughness and calculation of the flatness error was based on the Minimum Zone Method. The percentage discrepancy of measurement computed from experimental data is then used to determine the number of sample points (sample size).

R. Elansezhian, B. Ramamoorthy, P. Kesavan Nair
Effect of surfactants on the surface roughness of electroless Ni-P coating

Electroless nickel (EN) coatings have gained widespread acceptance as it provides uniform deposit on irregular surfaces, direct deposition on surface activated non – conductors, high hardness and excellent resistance to wear, abrasion and corrosion. The effect of surfactants on the surface roughness of electroless Nickel – Phosphorus surface protective coating obtained from an alkaline bath is presented in this paper. In this study the influence of surfactants sodium dodecylsulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB) on the surface roughness of coated samples were investigated. It was observed that the surface roughness, surface hardness and surface morphology of Ni-P coating were clearly influenced by the addition of surfactants SDS and CTAB. The complete experimental details, results obtained and their analysis are presented in this paper.

U. Paul Kumar, Basanta Bhaduri, N. Krishna Mohan, M. P. Kothiyal
Two wavelength microscopic TV interferometric system for surface profiling

Non-contact techniques for rapid and accurate mapping of micro-machined surfaces are important for the optoelectronic industry. Interferometry is an important tool for precision metrology of surfaces. It has been used for applications such as surface profiling, roughness measurement and quality testing of optical elements. The singlewavelength conventional interferometry can handle the smoothly varying surface profiles and step-heights less than half a wavelength. In this paper we describe a two wavelength microscopic TV interferometric system which removes ambiguity associated with the single wavelength data and also extends the phase measurement range compared to the conventional single wavelength interferometry. The results obtained using this two wavelength microscopic system for 3D surface profiling on smooth specimens are presented.

G. Balaganesan, L. Vijayaraghavan
Surface roughness modeling in face milling of metal matrix composites by fuzzy subtractive clustering method

A fuzzy modeling approach is presented in this paper for the prediction of surface roughness (Ra) in face milling of Metal Matrix Composites (MMC). This study deals with the experimental results obtained during face milling of MMC Al/SiC, 15% volume fraction by using face milling cutter with K10 grade insert. The data used for the training and checking of the model performance were obtained from experiments conducted on a vertical milling machine. The model uses the cutting speed, depth of cut and the feed as input data and the surface roughness as the output data. The process of model building is carried out by using subtractive clustering in both the input and output spaces. A minimum error model is obtained through exhaustive search of the clustering parameters. The fuzzy model obtained is capable of predicting the surface quality for a given set of inputs (the cutting speed, depth of cut and the cutting feed). This model is verified experimentally using different sets of inputs.

S. Z. Zahwi, A. Mekawi
Three dimensional (3D) surface measurements based on (2D) stylus instrument

Three dimensional measurements (3D) of surface topography are increasingly being recognized as the most adequate method for obtaining a better understanding of surfaces. The dimensional and surface metrology department at the National Institute for Standards in Egypt (NIS) developed a computer-controlled system for 3D surface measurements. The developed system is based on a 2D surface measuring instrument using a stylus contact method. A positioning table is used to displace the specimen underneath the stylus in a cross direction to the traverse stroke. The system can scan small areas on the measured surface (5.6 mm × 0.56 mm) by traversing the stylus of the measuring instrument over the surface in parallel traces. The system consists of a “Talysurf 10” stylus surface measuring instrument interfaced to an “IBM” compatible PC computer with a data acquisition device (DAQ). The (DAQ) is used to control the movement of the measuring stroke of the pick up in the X – axis, to control the movement of the positioning table in a cross direction to the stroke as Y- axis, and to take the data of each profile from the stylus vertical movements during the measurement stroke as Z-axis.
The software for the mentioned controls is made using “Labview” programming language. All data of the 3D surface are taken using unfiltered skid less mode of operation. A “Matlab” software is developed and used to take out the trend of the surface using a least square surface plane, then an approximation of a Gaussian filter (moving average) is used to filter the data. A software to analyze the data to get the 3D surface parameters and functions is also developed.

M. Arunachalam, G. Arumaikkannu
Evaluation of surface finish, form and dimensional accuracy of 3DP rapid prototypes

Three Dimensional Printing (3DP) is one among the Rapid Prototyping (RP) techniques that is evolving towards Rapid Manufacturing (RM). Speed and accuracy are the functional requirements of an RP system. The prototype quality is evaluated by surface finish, dimensional and form accuracy obtained from RP process. There is lack of published data dealing with influence of process parameters on prototype quality in 3DP process. The experiment design was made using Taguchi orthogonal array and a evaluation model was built for each experimental run. Using a 3-D coordinate measuring machine and surface profilometer, a series of measurements in evaluating the 3DP parts quality has been conducted and nonlinear regression model was developed to find the functional relationships between the response variables and process parameters of 3DP. SEM images were taken on 3DP models to study surface topography. The optimal setups of 3DP process parameters for obtaining better prototype quality is proposed.

K. Deepak Lawrence, L. M. Lakshmanan, S. Sathish Kumar
Prediction of surface roughness by measuring flank wear and cutting forces in turning process

Modeling and prediction of surface finish of work pieces in machining can play an important role in the automation of manufacturing operations. As surface generation in machining is a complex process, the exact variables and parameters that have to be used for surface roughness prediction models are still under dispute. This work attempts to evaluate and predict surface roughness during turning operation using artificial neural network and multiple regression analysis. In addition to the conventional cutting conditions like cutting speed, feed and depth of cut, this work also used cutting force ratio, cutting time and flank wear of the cutting tool to train the predictive models. The developed models were found to be capable of better predicting the surface roughness with very minimum RMS error and high correlation coefficient compared to earlier works.

V. Elango, L. Karunamoorthy
Modeling the lighting conditions for the estimation of surface roughness by machine vision using design of experiments

The influence of the lighting conditions on the grey level distribution and thereby on the estimation of the surface roughness using machine vision system is reported in this work. The light to specimen distance, the grazing angle and the inclination of the striations are varied and their effect on the image parameter, the arithmetic average of the grey level is studied. Mild steel, brass and aluminium specimens are machined for different roughness for the study. Trials were made using the design of experiments procedure and the influence of the different factors are studied. Taguchi’s signal to noise ratio method is applied to find the optimal lighting conditions. A model is developed to establish the relationship between the lighting conditions and the image parameter.

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