Browsing by Author "Joy, R."

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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 0Â°, 30Â° and 60Â° with different parameters in the machining range. The behaviour of cutting speeds for Taguchi's L9 set of experiments at 0Â°, 30Â° and 60Â° 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 Î¼m at 0Â° and for the lowest cutting speed parameter, it was measured 6.4 Î¼m lowest at 60Â° compared to the remaining angle of cut. The variation of micro-hardness at 0Â°, 30Â° and 60Â° 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 0Â°. However further it is increased to 173Hv and 180Hv at 30Â° and 60Â° angle of cut respectively. Â© 2019 Elsevier Ltd.
Investigation of machining parameters on corner accuracies for slant type taper triangle shaped profiles using WEDM on Hastelloy X
(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.
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 0Â° and 30Â° 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 30Â° than in 0Â° 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. Â© 2019 Published under licence by IOP Publishing Ltd.
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.