Faculty Publications

Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736

Publications by NITK Faculty

Browse

Author: search.filters.author.Manjaiah, M.Subject: search.filters.subject.Wire

Search Results

Now showing 1 - 6 of 6
  • No Thumbnail Available
    Item
    Experimental investigations on performance characteristics in wire electro discharge machining of Ti50Ni42.4Cu7.6 shape memory alloy
    (2013) Narendranath, S.; Manjaiah, M.; Basavarajappa, S.; Gaitonde, V.N.
    This article investigates the effect of pulse on time, peak current and pulse off time on wire electro discharge machining characteristics of Ti 50Ni42.4Cu7.6 shape memory alloy. A Ti 50Ni42.4Cu7.6 alloy was prepared by conventional tungsten arc melting. The machining experiments were performed as per Box-Behnken design on computer control wire electro discharge machining machine using molybdenum wire electrode. The relationships between the process parameters (pulse on time, peak current and pulse off time) and wire electro discharge machining responses (surface roughness and material removal rate) have been established using response surface methodology-based quadratic models. The analysis of variance has been employed to test the significance of the developed second-order mathematical models. The parametric analysis-based results reveal that low peak current with prolonged pulse on duration leads to reduced surface roughness. However, combination of low peak current with low pulse on time is beneficial for achieving better material removal rate for machining of shape memory alloy. © IMechE 2013.
  • No Thumbnail Available
    Item
    Wire electric discharge machining characteristics of titanium nickel shape memory alloy
    (Nonferrous Metals Society of China B12 Fuxing Road Beijing 100814, 2014) Manjaiah, M.; Narendranath, S.; Basavarajappa, S.; Gaitonde, V.N.
    TiNi shape memory alloys (SMAs) have been normally used as the competent elements in large part of the industries due to outstanding properties, such as super elasticity and shape memory effects. However, traditional machining of SMAs is quite complex due to these properties. Hence, the wire electric discharge machining (WEDM) characteristics of TiNi SMA was studied. The experiments were planned as per L27 orthogonal array to minimize the experiments, each experiment was performed under different conditions of pulse duration, pulse off time, servo voltage, flushing pressure and wire speed. A multi-response optimization method using Taguchi design with utility concept has been proposed for simultaneous optimization. The analysis of means (ANOM) and analysis of variance (ANOVA) on signal to noise (S/N) ratio were performed for determining the optimal parameter levels. Taguchi analysis reveals that a combination of 1 ?s pulse duration, 3.8 ?s pulse off time, 40 V servo voltage, 1.8×105 Pa flushing pressure and 8 m/min wire speed is beneficial for simultaneously maximizing the material removal rate (MRR) and minimizing the surface roughness. The optimization results of WEDM of TiNi SMA also indicate that pulse duration significantly affects the material removal rate and surface roughness. The discharged craters, micro cracks and recast layer were observed on the machined surface at large pulse duration.
  • No Thumbnail Available
    Item
    Effect of electrode material in wire electro discharge machining characteristics of Ti50Ni50-xCux shape memory alloy
    (Elsevier Inc. usjcs@elsevier.com, 2015) Manjaiah, M.; Narendranath, S.; Basavarajappa, S.; Gaitonde, V.N.
    Abstract TiNiCu alloy belongs to new class of shape memory alloy (SMA), which exhibits superior properties like shape memory effect, super elasticity and reversible martensitic transformation phase and thus find broad applications in actuators, micro tools and stents in biomedical components. Even though, SMA demonstrates outstanding property profile, traditional machining of SMAs is fairly complex and hence non-traditional machining like wire electric discharge machining (WEDM) has been performed. Hence, there is a need to investigate the WEDM performance characteristics of shape memory alloys due to excellent property profile and potential applications. In the present investigation, various machining characteristics like material removal rate (MRR), surface roughness, surface topography and metallographic changes have been studied and the influence of wire material on TiNiCu alloy machining characteristics has also been evaluated through ANOVA. Ti50Ni50-xCux=10, 20 was prepared by vacuum arc melting process. The proposed alloy as-cast material exhibits austenite property (B2 phase) and having higher hardness when compared to TiNi alloy. The investigation on WEDM of Ti50Ni50-xCux alloy reveals that the machining parameters such as servo voltage, pulse on time and pulse off time are the most significant parameters affecting MRR as well as surface roughness using both brass and zinc coated brass wires. However, machining with zinc coated brass wire yields reduced surface roughness and better MRR and also produces less surface defects on the machined surface of Ti50Ni50-xCux alloys. © 2015 Elsevier Inc. All rights reserved.
  • No Thumbnail Available
    Item
    Influence of process parameters on material removal rate and surface roughness in WED-machining of Ti50Ni40Cu10 shape memory alloy
    (Inderscience Publishers, 2016) Manjaiah, M.; Narendranath, S.; Basavarajappa, S.; Gaitonde, V.N.
    Among the shape memory alloys (SMAs), TiNi SMAs have been typically used as the functional elements in the larger part of the industries due to exceptional properties like super elasticity and shape memory effect. However, traditional machining of these alloys is fairly complex due to these properties. The non-traditional machining process like electric discharge machining (EDM) exhibits outstanding capability in machining of these alloys. The poor selection of machining parameters may cause increased roughness of workpiece and lesser material removal rate. Hence, an effort has been made in the present work to explore the effects of three process parameters, such as pulse on time, pulse off time and servo voltage in wire electric discharge machining (WEDM) of Ti50Ni40Cu10 shape memory alloy (SMA) using zinc coated brass wire electrode on material removal rate and surface roughness using response surface methodology (RSM)-based mathematical models. The experiments were planned as per central composite design (CCD). The investigations revealed that pulse on time and servo voltage have predominant effects in maximising material removal rate and minimising surface roughness. The best combination of the process parameters for multi-response optimisation was obtained through desirability function. ©2016 Inderscience Enterprises Ltd.
  • No Thumbnail Available
    Item
    Wire Electro Discharge Machining Performance of TiNiCu Shape Memory Alloy
    (Springer Netherlands, 2016) Manjaiah, M.; Narendranath, S.; Basavarajappa, S.
    The study presents the effect of Wire Electro Discharge Machining (WEDM) system parameters on the Material Removal Rate (MRR), surface roughness and surface morphology of Ti 50Ni 45Cu 5 SMA developed using vacuum arc melting. The WEDM parameters such as pulse on time, peak current, pulse off time and table feed were selected as control factors over MRR and surface roughness. The results reveal that the surface roughness and MRR increases with increased peak current, pulse on time and table feed but decreases slightly with pulse off time. Higher MRR was attained at 5Amps peak current and 70 ?m/s table feed. Better surface roughness was obtained for a combination of lower pulse on time, peak current and table feed with high pulse off time. Surface defects such as recast layer, craters, micro–cracks, pockmarks and voids were found on the machined surface. The globule of appendages formed around the craters and the intensity of the crater was evident for the higher surface roughness with an increase in peak current and pulse-on time during WEDM. © 2015, Springer Science+Business Media Dordrecht.
  • No Thumbnail Available
    Item
    Optimization and Prediction of Responses Using Artificial Neural Network and Adaptive Neuro-Fuzzy Interference System during Taper Profiling on Pyromet-680 Using Wire Electric Discharge Machining
    (Springer, 2023) Manoj, I.V.; Manjaiah, M.; Narendranath, S.
    In the present study, taper cutting is performed with the aid of a uniquely designed fixture. This is attempted to avoid the difficulties in tapering using wire electric discharge machining like wire break, dimensional error, guide wear, non-uniform flushing and low surface quality. An investigation of output parameters was made during taper machining using a fixture. The cutting rate (CR) and surface roughness (SR) were considered for response surface optimization (RSM) as they were important response parameters that indicate the quality of a machined component. It is observed that servo gap voltage and pulse act contrastingly on the output parameters. For achieving a trade-off of input parameters with output responses, RSM optimization is selected during taper profiling. There were 3-5% variations for both CR and SR when compared to experimental and RSM optimal values. The tapered profile slots of different angles like 0°, 15° and 30° were machined on Pyromet-680 using optimal machining parameters. The effect of different profiling parameters like wire distance between guides (WD), dwell time (DT), profile offset (PO) and cutting speed override (CO) on output responses like CR and SR was analyzed. Adaptive neuro-fuzzy interference system (ANFIS) and artificial neural network (ANN) models have been established for the prediction of the output responses. The validation is performed by experimentation, and the prediction errors ranged from 0 to 5% for both the responses CR and SR in ANFIS models. So ANFIS models proved to be the most efficient as there is an improvement of 45-50% in prediction compared to ANN models. © 2022, ASM International.