Faculty Publications
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Item Investigation of cutting speed, recast layer and micro-hardness in angular machining using slant type taper fixture by WEDM of Hastelloy X(Elsevier Ltd, 2019) Joy, R.; Manoj, I.V.; Narendranath, S.Wire electric discharge machining (WEDM) is a thermo-electric spark erosion process that can machine any difficult to cut materials. Taper cutting in WEDM is a unique feature that has many problems such as taper angular inaccuracies, wire cut and distribution of dielectric fluid during machining. In the present research work, angular machining is performed for generating a tapered component using a novel slant type taper fixture which overcomes the disadvantages of taper cutting in WEDM. The machining was performed on Hastelloy X at various angles namely 0°, 30° and 60° with different parameters in the machining range. The behaviour of cutting speeds for Taguchi's L9 set of experiments at 0°, 30° and 60° angle of tilt in machining was reported. The cutting speed is ranging from 0.16 mm/min to 2.49 mm/min during angular machining. From the SEM micrographs, the highest average recast layer thickness for highest cutting speed parameter was 26.4 μm at 0° and for the lowest cutting speed parameter, it was measured 6.4 μm lowest at 60° compared to the remaining angle of cut. The variation of micro-hardness at 0°, 30° and 60° tapered components at the highest cutting speed parameter were measured using Vickers micro-hardness test. The lowest Vickers hardness was found to be 167Hv at 0°. However further it is increased to 173Hv and 180Hv at 30° and 60° angle of cut respectively. © 2019 Elsevier Ltd.Item Investigation of machining parameters on corner accuracies for slant type taper triangle shaped profiles using WEDM on Hastelloy X(Institute of Physics Publishing helen.craven@iop.org, 2019) Manoj, I.V.; Joy, R.; Narendranath, S.; Nedelcu, D.Wire electro-discharge machining (WEDM) is a widely used machining process for machining of difficult to cut materials, which are used in precision profile applications like dies, metal stampings, and gas turbine parts. In the present research work, a new slant type taper fixture was used to obtain angular machining of triangular shape slots of sides 1mm, 3mm and 5mm machined both in 0° and 30° as slant angles on Hastelloy X. The corner radius and corner errors were investigated for different machining parameters like corner dwell time (CDT), offset distance (WO), wire guide distance (WGD) and cutting speed override (CSO) using L16 orthogonal array for both the slant angles. SEM micrographs indicated that corners were with lower radii at 30° than in 0° slant profiles, at lowest and highest cutting speeds. The main effects plot showed that the corner radius increases with the increase in wire offset and wire guide distance parameters. The increase in corner dwell time has an adverse effect on the corner radius. The triangles were machined at different cutting speeds from 0.47 to 1.51 mm/min with various parameters; it was observed that as the corner radius decreases the corner error also reduces. However, the corner radius and corner error can be minimized by selecting an optimized cutting parameter. © 2019 Published under licence by IOP Publishing Ltd.Item Optimization and prediction of machining responses using response surface methodology and adaptive neural network by wire electric discharge machining of alloy-x(Trans Tech Publications Ltd, 2021) Manoj, I.V.; Narendranath, S.; Pramanik, A.Wire electric discharge machining non-contact machining process based on spark erosion technique. It can machine difficult-to-cut materials with excellent precision. In this paper Alloy-X, a nickel-based superalloy was machined at different machining parameters. Input parameters like pulse on time, pulse off time, servo voltage and wire feed were employed for the machining. Response parameters like cutting speed and surface roughness were analyzed from the L25 orthogonal experiments. It was noted that the pulse on time and servo voltage were the most influential parameters. Both cutting speed and surface roughness increased on increase in pulse on time and decrease in servo voltage. Grey relation analysis was performed to get the optimal parametric setting. Response surface method and artificial neural network predictors were used in the prediction of cutting speed and surface roughness. It was found that among the two predictors artificial neural network was accurate than response surface method. © 2021 Trans Tech Publications Ltd, Switzerland.Item Influence of machining parameters on taper square areas during slant type taper profiling using wire electric discharge machining(IOP Publishing Ltd, 2021) Manoj, I.V.; Narendranath, S.The oblique/tapered machining is a unique method in wire electric discharge machining to get taper profiles difficult to machine materials. These profiles have many applications like dies, nozzles, inserts, cutting tools and other components. In the present study, a simple square profile is machined using a slant type fixture to achieve a tapered profile made of Hastelloy X. A simple square is machined at different slant angles to get a 0 , 15 and 30 tapered profiles. This paper aims to study the effects of the machining parameters like wire guide distance, wire offset, corner dwell time and cutting speed override on the area of machined profiles. Both scanning electron microscope and coordinate measuring machine were used to measure the areas of 1mm and 5mm. It is observed that as the wire guide distance and cutting speed override increases the area decreases. Whereas in case of wire offset, as offset increases the areas also increase and corner dwell time doesn't affect on the area. As the angle increased the area also increased leading to bigger taper profiles. © Published under licence by IOP Publishing Ltd.Item Machining and forecasting of square profile areas using artificial neural modelling at different slant angles by WEDM.(IOP Publishing Ltd, 2021) Manoj, I.V.; Narendranath, S.Wire electric discharge machining non-conventional process that removes materials by thermal erosion. Tapering in WEDM has many applications in machining accurate geometric profiles. In the present investigation, a slant type taper machining was performed to produce taper profiles with the help of the slant fixture. The machining parameters such as wire guide distance, corner dwell time, wire offset and cutting speed override was employed to find the variation in the taper profile area. A simple square profile of 1mm, 3mm and 5mm was machined at different slant angles namely 0°, 15° and 30°. It was observed that each parameter yielded different profile areas. The artificial neural network was used for the forecasting the areas of 1mm, 3mm and 5mm square for different parameters. The optimum artificial neural network model was experimentally validated and the errors were ranging from 0-10%. © Published under licence by IOP Publishing Ltd.Item Effect of Profile Geometry and Cutting Speed Override Parameter on Profiling Speed During Tapering Using Wire Electric Discharge Machining(Springer Science and Business Media Deutschland GmbH, 2022) Manoj, I.V.; Narendranath, S.The oblique/tapered form of precise components has many applications like dies, nozzles, inserts, cutting tools, and other components. Wire electric discharge machining is an erosion technique that helps in precise machining of hard materials. In the present study, basic profiles were machined using a novel slant-type fixture to achieve a slant surface on Hastelloy X. The shapes like triangle, square, and circle are machined at different slant angles, namely 0° and 30°. This paper aims to study the effects of the cutting speed override parameter and profile geometry on profiling speed of machined profiles. The basic shapes of 1, 3, and 5 mm sides were machined. The cutting speed override parameter affected the most on profiling speed in both the angles irrespective of profiles. The profile geometry also affects the profiling speed although the machining parameters were maintained constant. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Parametric Analysis and Response Surface Optimization of Surface Roughness and Cutting Rate in the Machining Using WEDM(Springer Science and Business Media Deutschland GmbH, 2022) Manoj, I.V.; Narendranath, S.Nickelvac HX is an amalgamation of nickel, chromium, iron, molybdenum etc. As nickel-based alloys have high-temperature strength they can be used in many applications like afterburners, blades of turbines, turbocharges, submarines parts etc. Wire electric discharge machining a non-contact spark machining was found to be the most precise machining process. Among the WEDM parameters, different process parameters like servo voltage, pulse on time, cutting speed override and pulse off time were employed for the examination. It was noticed that both response characteristics increased with the increase in cutting speed override and pulse on-time. In the case of servo voltage and pulse off time, as it was increased the cutting rate and surface roughness diminished. The effects of cutting rate on surface roughness and microhardness were analyzed. The response surface optimization was employed for optimizing surface roughness and cutting rate as it controls product quality. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Investigation on the Effect of Variation in Cutting Speeds and Angle of Cut During Slant Type Taper Cutting in WEDM of Hastelloy X(Springer, 2020) Manoj, I.V.; Joy, R.; Narendranath, S.Nickel-based superalloys are classified under difficult to machine materials due to its higher affinity to tool materials and low thermal diffusivity. Wire electric discharge machining (WEDM) is a spark eroding technique for precise machining of such superalloys with complex machining geometries. Tapering in WEDM has many disadvantages like wire break, angular inaccuracies and dielectric distribution for better surfaces. In this paper, a unique method was developed and employed to achieve taper surface by tilting the workpiece using a slant type taper fixture for machining of tapered surfaces. Different aspects like cutting thickness, surface roughness, slant angle, surface crack density and width of cut were examined for five distinct cutting speed parameters at different angles, namely 0°, 15°, 30°, 45° and 60°. In the present research work, Hastelloy X was machined using zinc-coated copper wire and cutting speed was ranged between 0.16 and 2.49 mm/min. The slant angle was observed to be independent of cutting speed, and it was influenced by wire vibration, manufacturing imprecisions of slant fixture. It was found that as the cutting speed increases, surface crack density and surface roughness also increase. It was observed that both the parameters increased with the increase in the angle of cut from 0° to 60° although the cutting speed decreased. © 2019, King Fahd University of Petroleum & Minerals.Item Variation and artificial neural network prediction of profile areas during slant type taper profiling of triangle at different machining parameters on Hastelloy X by wire electric discharge machining(SAGE Publications Ltd, 2020) Manoj, I.V.; Narendranath, S.In the present research work, an in-house developed fixture is used to achieve taper profiles which avoids the disadvantages in convention tapering operation in wire electric discharge machining like wire bend, inaccuracies in taper, insufficient flushing, guide wear etc. A simple triangular profile was machined at 0°, 15° and 30° slant/taper angles. These taper profile areas are investigated for various machining parameters like wire guide distance, corner dwell time, wire offset and cutting speed override. It is observed that as the wire guide distance and cutting speed override increases, the profile area decreases. Whereas in case of wire offset, as offset increases the profile areas also increase. The corner dwell time parameter do not effect on the profile area. The taper profile areas measured highest at 30° followed by 15° and 0° slant angles. This is due to the workpiece placed at different angles during machining with the aid of fixture to obtain taper profile. The taper angle represents the angularity of slant triangular profiles. As the slant angle increases the variation in taper error also increases due to higher wire vibration. An artificial neural network model is developed for the prediction of these areas at a different slant angle. The model is validated experimentally where the errors in prediction ranged from 1% to 9%. In conclusion, it can be noticed that the machining parameters and slant angle influence on profiles irrespective of their dimensions. © IMechE 2020.Item Slant type taper profiling and prediction of profiling speed for a circular profile during in wire electric discharge machining using Hastelloy-X(SAGE Publications Ltd, 2021) Manoj, I.V.; Narendranath, S.Hastelloy-X a nickel-based alloy used in nozzles, flame holders, turbine blades, turbocharges, jet engine tailpipes, afterburner components etc. having complex tapering profiles. Wire electric discharge machining proves to be the most beneficial machining technique as it provides required accuracy for the components. In the present research, a slant type taper fixture is employed for achieving taper angles as convention tapering have many hindrances like wire bend, angular inaccuracy, guide wear, insufficient flushing and wire breakage etc. and machining a simple circular profile on Hastelloy-X. The behaviour of different output parameters like profiling speed, surface roughness, profile areas, microhardness and recast layer were investigated for various input parameters for machined taper components at 0°, 15° and 30°. The cutting speed override parameter influenced most on the profiling speed and surface roughness. The wire offset parameter was found to be the most significant factor in the case of circular profile areas that were machined. The variation of different output parameters to profiling/cutting speed and taper angle was also highlighted. It is found the recast layer decreased which indicated lesser thermal degradation at higher taper angles at different profiling parameters. This is also validated by the microhardness where the machined surface hardness of taper angular profiles was found to be greater than the 0° profiles. The artificial neural networks and adaptive neuro-fuzzy interference system were used for the prediction of profiling speed. The adaptive neuro-fuzzy interference system was found better in prediction as the percentage error varies between 0–5 per cent. In conclusion, the profiling speed influences both on the accuracy and surface of machined taper circular profiles. © IMechE 2021.