International Journal of Precision Technology http://www.inderscience.com/browse/index.php?journalID=270&year=2011&vol=2&issue=4 Inderscience Publishers Ltd en-uk International Journal of Precision Technology 1755-2060 1755-2079 © 2011 Inderscience Publishers Ltd editor@inderscience.com https://www.inderscience.com/images/files/coverImgs/ijptech_scoverijptech.jpg http://www.inderscience.com/browse/index.php?journalID=270&year=2011&vol=2&issue=4 http://www.inderscience.com/link.php?id=44899 The aim of the paper is to study the electrochemical micromachining (µECM) tool preparation technique and in particular it investigates the effects of µECM parameters such as applied potential, electrolytic concentration, tool positions on final tool shape and dimensions. During microtool fabrication, tungsten microshafts of 0.38 mm are electrochemically etched to make the desired cylindrical tools with conical tips. Electrolyte concentrations are varied in the range of 0.1-1.4 M for the potential differences of 9 V and 15 V AC. The shape and size of the tools are also determined for each set of experiments. The tools thus fabricated are used to fabricate single-hole micronozzle and multiple-holes micronozzle array. Entrance and exit diameters of micronozzles fabricated are measured by SEM and compared to tool geometry. Etching behaviour of tungsten microtool and its applications in electrochemical micromachining
M.A.H. Mithu; G. Fantoni
International Journal of Precision Technology, Vol. 2, No. 4 (2011) pp. 301 - 312
The aim of the paper is to study the electrochemical micromachining (µECM) tool preparation technique and in particular it investigates the effects of µECM parameters such as applied potential, electrolytic concentration, tool positions on final tool shape and dimensions. During microtool fabrication, tungsten microshafts of 0.38 mm are electrochemically etched to make the desired cylindrical tools with conical tips. Electrolyte concentrations are varied in the range of 0.1-1.4 M for the potential differences of 9 V and 15 V AC. The shape and size of the tools are also determined for each set of experiments. The tools thus fabricated are used to fabricate single-hole micronozzle and multiple-holes micronozzle array. Entrance and exit diameters of micronozzles fabricated are measured by SEM and compared to tool geometry.

]]> 10.1504/IJPTECH.2011.044899 International Journal of Precision Technology, Vol. 2, No. 4 (2011) pp. 301 - 312 M.A.H. Mithu; G. Fantoni Department of Mechanical, Nuclear and Production Engineering, University of Pisa, Pisa, 56126 PI, Italy. ' Department of Mechanical, Nuclear and Production Engineering, University of Pisa, Pisa, 56126 PI, Italy electrochemical micromachining microtools conical microholes micronozzles electrochemical machining ECM tool preparation applied potential electrolytic concentration tool positions tungsten microshafts tool geometry. 2012-01-15T23:20:50-05:00 2 4 301 312 2012-01-15T23:20:50-05:00 http://www.inderscience.com/link.php?id=44900 Indian manufacturing companies have passed through the conventional manufacturing with quality control systems, 100% inspection, to a quality assuring TQM companies with robust designs to obtain PPM levels of customer returns. This study is about the hydrodynamic lubrication system in a hermetically sealed compressor to reduce the Taguchi loss function of bearing wear. Taguchi loss function is modified to include warranty. Loss/warranty period is a new parameter introduced. This parameter is lower the better, a lower value indicates less loss to society, more warranty period to customer. A product with less loss/warranty will lead to increased business to manufacturer. This parameter is used for the benefit of society, customer has more warranty period and increased business for the manufacturer. Study of warranty returned compressors was done to obtain the distribution of defects. System design, parameter design and tolerance design approach of Taguchi was adopted to obtain robustness. An improved life of product was obtained. Customers were provided with compressors so that the warranty may be increased from 18 months to five years, with no financial loss also the manufacturer had consistent reliable products. Robust design of hydrodynamic bearings: adopting Taguchi methods towards zero defects of a hermetic compressor
Suresh Akella; Leela Prasad; N. Venkateswarlu
International Journal of Precision Technology, Vol. 2, No. 4 (2011) pp. 313 - 324
Indian manufacturing companies have passed through the conventional manufacturing with quality control systems, 100% inspection, to a quality assuring TQM companies with robust designs to obtain PPM levels of customer returns. This study is about the hydrodynamic lubrication system in a hermetically sealed compressor to reduce the Taguchi loss function of bearing wear. Taguchi loss function is modified to include warranty. Loss/warranty period is a new parameter introduced. This parameter is lower the better, a lower value indicates less loss to society, more warranty period to customer. A product with less loss/warranty will lead to increased business to manufacturer. This parameter is used for the benefit of society, customer has more warranty period and increased business for the manufacturer. Study of warranty returned compressors was done to obtain the distribution of defects. System design, parameter design and tolerance design approach of Taguchi was adopted to obtain robustness. An improved life of product was obtained. Customers were provided with compressors so that the warranty may be increased from 18 months to five years, with no financial loss also the manufacturer had consistent reliable products.

]]> 10.1504/IJPTECH.2011.044900 International Journal of Precision Technology, Vol. 2, No. 4 (2011) pp. 313 - 324 Suresh Akella; Leela Prasad; N. Venkateswarlu Department of Mechanical Engineering, Vignan Institute of Technology & Science, Vignan Hills, Deshmukhi, Nalgonda District, 508284, India. ' Department of Mechanical Engineering, Vignan Institute of Technology & Science, Vignan Hills, Deshmukhi, Nalgonda District, 508284, India. ' Department of Mechanical Engineering, Vignan Institute of Technology & Science, Vignan Hills, Deshmukhi, Nalgonda District, 508284, India Taguchi methods hydrodynamic bearings hermetic compressors Taguchi loss function robust design warranty tolerances zero defects India hydrodynamic lubrication bearing wear warranty periods system design parameter design tolerance design. 2012-01-15T23:20:50-05:00 2 4 313 324 2012-01-15T23:20:50-05:00 http://www.inderscience.com/link.php?id=44901 Natural frequencies of passive radio frequency identification (RFID) tags were studied as they played a great role for their reliability. Both analytical and numerical predictions indicated that natural frequencies were in the kilohertz range; tags must not have been suffered resonance. But in reality, tags used to fail when subjected to low frequency vibrations. Anisotropic conductive adhesive (ACA), a commonly used bonding agent, was detected as the responsible item for these failures. A new bonding method has been put forward that would replace ACA by lead free S-Bond solder material to connect flip chip of an RFID tag to substrate antenna. Having better strength and adhesion characteristics, joints with S-Bond would provide improved bonding as established by analytical and numerical estimation and supported by experimentation. Failure of flip-chip joints in passive RFID tags and an alternative joining method
M.S. Islam; Z.Y. Wang
International Journal of Precision Technology, Vol. 2, No. 4 (2011) pp. 325 - 339
Natural frequencies of passive radio frequency identification (RFID) tags were studied as they played a great role for their reliability. Both analytical and numerical predictions indicated that natural frequencies were in the kilohertz range; tags must not have been suffered resonance. But in reality, tags used to fail when subjected to low frequency vibrations. Anisotropic conductive adhesive (ACA), a commonly used bonding agent, was detected as the responsible item for these failures. A new bonding method has been put forward that would replace ACA by lead free S-Bond solder material to connect flip chip of an RFID tag to substrate antenna. Having better strength and adhesion characteristics, joints with S-Bond would provide improved bonding as established by analytical and numerical estimation and supported by experimentation.

]]> 10.1504/IJPTECH.2011.044901 International Journal of Precision Technology, Vol. 2, No. 4 (2011) pp. 325 - 339 M.S. Islam; Z.Y. Wang Department of Mechanical Engineering, Howard Hughes College of Engineering, 4505 S Maryland Parkway, Las Vegas, NV 89154-4027, USA. ' Department of Mechanical Engineering, Howard Hughes College of Engineering, 4505 S Maryland Parkway, Las Vegas, NV 89154-4027, USA micron-sized joint failure flip chips precision RFID tags tag assembly vibration S-Bond solders anisotropic conductive adhesive ACA radio frequency identification bonding agents lead free soldering strength adhesion. 2012-01-15T23:20:50-05:00 2 4 325 339 2012-01-15T23:20:50-05:00 http://www.inderscience.com/link.php?id=44902 Surface roughness is one of the most important parameters used to evaluate the surface integrity of the machined components. Therefore, in this work an attempt has been made to investigate the effect of the cutting parameters (cutting speed, feed rate and depth of cut) on the surface roughness in machining the nimonic C-263 alloy. An empirical model has been developed for predicting the surface roughness, using the response surface methodology (RSM) and artificial neural networks (ANN). The experimental results revealed that among the parameters considered, the feed rate is the most significant machining parameter, which influences the surface roughness. The predicted values and measured values are fairly close, which indicates that the developed model can be effectively used to predict the surface roughness in the machining of the nimonic C-263 alloy. A comparison of the neural network models with the regression model was carried out. The influence of the different parameters and their interactions are studied and presented in this study. Surface roughness analysis on machining of nimonic C-263 alloy using ANN and RSM techniques
C. Ezilarasan; V.S. Senthil Kumar; A. Velayudham; K. Palanikumar
International Journal of Precision Technology, Vol. 2, No. 4 (2011) pp. 340 - 354
Surface roughness is one of the most important parameters used to evaluate the surface integrity of the machined components. Therefore, in this work an attempt has been made to investigate the effect of the cutting parameters (cutting speed, feed rate and depth of cut) on the surface roughness in machining the nimonic C-263 alloy. An empirical model has been developed for predicting the surface roughness, using the response surface methodology (RSM) and artificial neural networks (ANN). The experimental results revealed that among the parameters considered, the feed rate is the most significant machining parameter, which influences the surface roughness. The predicted values and measured values are fairly close, which indicates that the developed model can be effectively used to predict the surface roughness in the machining of the nimonic C-263 alloy. A comparison of the neural network models with the regression model was carried out. The influence of the different parameters and their interactions are studied and presented in this study.

]]> 10.1504/IJPTECH.2011.044902 International Journal of Precision Technology, Vol. 2, No. 4 (2011) pp. 340 - 354 C. Ezilarasan; V.S. Senthil Kumar; A. Velayudham; K. Palanikumar Department of Mechanical Engineering, College of Engineering, Anna University, Guindy, Chennai-25, India. ' Department of Mechanical Engineering, College of Engineering, Anna University, Guindy, Chennai-25, India. ' Combat Vehicles Research and Development Establishment, Chennai-54, Avadi, India. ' Sri Sairam Institute of Technology, Chennai-44, India nimonic C-263 alloys surface roughness response surface methodology RSM artificial neural networks ANNs surface quality cutting speed feed rate depth of cut. 2012-01-15T23:20:50-05:00 2 4 340 354 2012-01-15T23:20:50-05:00 http://www.inderscience.com/link.php?id=44903 In this study, coated carbide, deep cryogenically treated uncoated/coated carbide inserts were used for finish turning of hardened AISI H11 steel (50 HRC) under dry conditions. Both uncoated and coated carbide inserts were deep cryogenically treated at –196°C. The turning performance of both treated and untreated carbide inserts was evaluated in terms of maximum flank wear of inserts, surface roughness, white layer formation, micro-hardness variation and residual stress generated on the machined surface. The machining experiments showed that the performance of carbide inserts was better up to cutting speed of 137 m/min, while the performance deteriorated at higher cutting speeds. The white layer thickness varies from 1.2 µm to 2.2 µm for all the cutting conditions tested. The coated inserts with wiper geometry produced a surface finish less than 1.6 µm for all the cutting conditions tested, while in some of the cases with uncoated carbide inserts the Ra value was higher than 1.6 µm. The performance of deep cryogenically treated inserts was better as compared to the untreated carbide inserts in terms of both tool wear and surface integrity of machined surface. Machinability and surface integrity issues in finish turning of hardened steel with coated carbide, deep cryogenically treated uncoated/coated carbide inserts
Manu Dogra; Vishal S. Sharma
International Journal of Precision Technology, Vol. 2, No. 4 (2011) pp. 355 - 374
In this study, coated carbide, deep cryogenically treated uncoated/coated carbide inserts were used for finish turning of hardened AISI H11 steel (50 HRC) under dry conditions. Both uncoated and coated carbide inserts were deep cryogenically treated at –196°C. The turning performance of both treated and untreated carbide inserts was evaluated in terms of maximum flank wear of inserts, surface roughness, white layer formation, micro-hardness variation and residual stress generated on the machined surface. The machining experiments showed that the performance of carbide inserts was better up to cutting speed of 137 m/min, while the performance deteriorated at higher cutting speeds. The white layer thickness varies from 1.2 µm to 2.2 µm for all the cutting conditions tested. The coated inserts with wiper geometry produced a surface finish less than 1.6 µm for all the cutting conditions tested, while in some of the cases with uncoated carbide inserts the Ra value was higher than 1.6 µm. The performance of deep cryogenically treated inserts was better as compared to the untreated carbide inserts in terms of both tool wear and surface integrity of machined surface.

]]> 10.1504/IJPTECH.2011.044903 International Journal of Precision Technology, Vol. 2, No. 4 (2011) pp. 355 - 374 Manu Dogra; Vishal S. Sharma Department of Mechanical Engineering, SSG Panjab University Regional Centre, Hoshiarpur, Punjab, India. ' Department of Industrial and Production Engineering, Dr B.R. Ambedkar National Institute of Technology, Jalandhar, 144011, Punjab, India CVD coated carbide-wiper geometry cryogenic treatment hard turning white layer machine-affected zone MAZ machinability surface integrity finish turning hardened steel coated carbide inserts flank wear tool wear surface roughness microhardness residual stress cutting speeds surface quality. 2012-01-15T23:20:50-05:00 2 4 355 374 2012-01-15T23:20:50-05:00 http://www.inderscience.com/link.php?id=44904 In this paper, an investigation was conducted to understand the wear and frictional properties of kenaf fibre reinforced polyurethane composites. The effect of applied loads (30 to 80 N), sliding distance (up to 2.7 km), and fibre orientation [i.e., parallel (P-O), anti-parallel (AP-O) and normal (N-O)] were determined under dry and wet contact sliding. Specific wear rates for all fibre orientations improved under wet contact except parallel orientated composites. Presence of water in wet sliding has significantly reduced the friction coefficient compared to dry sliding besides acting as a cooling agent. A scanning electron microscope (SEM) was used to study the worn surfaces and wear mechanism encountered. The predominant wear mechanism observed under dry sliding was micro-cracks, plastic deformation and thermo-mechanical deformation. Meanwhile, the worn surfaces under wet contact are very minimal, namely micro-ploughing at elevated sliding distances. Investigations on wear and frictional properties of kenaf fibre polyurethane composites under dry and wet contact conditions
Narish Singh; B.F. Yousif; Dirk Rilling
International Journal of Precision Technology, Vol. 2, No. 4 (2011) pp. 375 - 387
In this paper, an investigation was conducted to understand the wear and frictional properties of kenaf fibre reinforced polyurethane composites. The effect of applied loads (30 to 80 N), sliding distance (up to 2.7 km), and fibre orientation [i.e., parallel (P-O), anti-parallel (AP-O) and normal (N-O)] were determined under dry and wet contact sliding. Specific wear rates for all fibre orientations improved under wet contact except parallel orientated composites. Presence of water in wet sliding has significantly reduced the friction coefficient compared to dry sliding besides acting as a cooling agent. A scanning electron microscope (SEM) was used to study the worn surfaces and wear mechanism encountered. The predominant wear mechanism observed under dry sliding was micro-cracks, plastic deformation and thermo-mechanical deformation. Meanwhile, the worn surfaces under wet contact are very minimal, namely micro-ploughing at elevated sliding distances.

]]> 10.1504/IJPTECH.2011.044904 International Journal of Precision Technology, Vol. 2, No. 4 (2011) pp. 375 - 387 Narish Singh; B.F. Yousif; Dirk Rilling Faculty of Engineering and Technology, Multimedia University, Jalan Ayer Keroh lama, 75450, Melaka, Malaysia. ' Faculty of Engineering and Surveying, University of Southern Queensland, Toowoomba, QLD 4350, Australia. ' Faculty of Engineering and Technology, Multimedia University, Jalan Ayer Keroh lama, 75450, Melaka, Malaysia adhesive wear kenaf fibre polyurethane composites wet contact dry contact water lubrication friction. 2012-01-15T23:20:50-05:00 2 4 375 387 2012-01-15T23:20:50-05:00