Papers by M.Pradeep Kumar
Procedia Materials Science, 2014
Procedia Engineering, 2013
Low density materials like Al 2024-T351 have found a wide range of applicability due to its capab... more Low density materials like Al 2024-T351 have found a wide range of applicability due to its capability of bearing high loads. To combat the need of extensive experimental trials to understand the orthogonal machining of Al 2024 T351, Finite element (FE) simulations have been employed. One of the most important parameters which determine the effectiveness of the FE code in the case of machining simulations is the flow stress model that is employed. However, there is a dearth of constitutive models in literature, capable of perfectly simulating the orthogonal machining of Al 2024 T351. The present work aims to assess and validate the performance of the JC constitutive equation in modelling the deformation behaviour of Al 2024-T351 alloy. Orthogonal machining experiments were conducted at nine different cutting conditions by varying cutting speed and feed. An FE model was constructed in Deform 2D and the flow stress data calculated from the JC model parameters, based on Oxley machining model was input into the FE code. The FE results for cutting force, chip thickness and temperature were compared with those of the experiments. The effective stress, strain and strain rate were analyzed for the various cutting conditions.
Journal of the Brazilian Society of Mechanical Sciences and Engineering
Secondary operation of boring is carried out to produce close geometric tolerance holes produced ... more Secondary operation of boring is carried out to produce close geometric tolerance holes produced in drilling. In this work, an attempt has been made in producing a hole by dry boring, wet boring and cryogenic boring of gunmetal. Gunmetal finds its application in areas of casting, steam turbines and pressure valves, due to its high resistance to corrosion. Investigation of cutting temperature generated during machining, cutting force experienced by the tool and surface roughness of the machined workpiece was toted out with analogous to cutting speed and feed, by Taguchi, ANOVA and TOPSIS analyses. Surface morphology study, tool wear analysis, residual stress analysis were done in order to distinguish the modification in the bored surface and tool material after machining. Cryogenic boring of gunmetal reduced the cutting temperature by 63.43% and 53.85% over dry boring and wet boring, respectively. Furthermore, cutting force is reduced by 34.51% and 18.29% over dry boring and wet boring, respectively. Additionally, a decrease of 62.23% and 35.10% is observed in surface roughness on comparing dry boring and wet boring with respect to cryogenic boring of gunmetal. Taguchi and ANOVA arbitrated speed as an imperative parameter for cutting force and feed as a paramount parameter in cutting temperature. Furthermore, speed is a crucial parameter for arbitrating surface roughness in dry boring and wet boring, additionally feed for surface roughness in cryogenic boring condition. TOPSIS analysis illuminated speed of 1200 rpm and feed of 0.055 mm/min as the most closest to exemplar elucidation for all three cutting preconditions. Aggrandizement in compressive residual stress is discerned in cryogenic boring by 39.74% and 19.35% correlated with dry boring and wet boring, respectively, as the material undergoes work hardening. A decrease in residual tensile stress is espied in cryogenic boring when juxtaposed to wet boring, ensuring upsurge in tool life and better surface characteristics. Microhardness in cryogenic boring of gunmetal improves by 5.83-11.05% and 0.51-2.57% analogous to dry boring and wet boring, respectively. Corrosion resistance in cryogenic boring increases by 77.43% and 49.25% analogous to dry boring and wet boring of gunmetal, respectively. The circularity and cylindricity increase by 4.76-98.40%, 8.33-97.50% and 6.25-97.15%, 2.43-92.85% in cryogenic boring juxtaposed to dry boring and wet boring of gunmetal, respectively.
This article describes the experimental investigation of abrasive water jet (AWJ) cutting on AA50... more This article describes the experimental investigation of abrasive water jet (AWJ) cutting on AA5083-H32 aluminum alloy. In this study, the influence of varying the jet impingement angles and abrasive mesh sizes with different water jet pressures, on the output parameters for the AWJ cutting of the aluminum alloy, was analyzed. The experimental results found that the output parameters, namely, the depth of penetration, top kerf width, kerf taper ratio, surface roughness, and abrasive contaminations, were strongly influenced by the combined effect of oblique jet impingement angles and abrasive mesh sizes on AWJ. Also, it is noticed that oblique jet impingement angles have more influence on the output cutting responses than the normal jet impingement angle, and consequently, each abrasive mesh size has an influence on the different output responses for the AWJ cutting of AA5083-H32. Scanning electron microscope and microhardness tester were used to examine the different cutting regions of the kerf wall surfaces. The Energy-dispersive X-ray spectroscopy analysis was used to confirm the amount of silicon particles embedded in the AWJ cut surfaces. The adequacy checking of the experimental data for the AWJ cutting performance models has been analyzed through the residual plots using the statistical software.
This paper describes how optimization studies were carried out on an abrasive water jet (AWJ) cut... more This paper describes how optimization studies were carried out on an abrasive water jet (AWJ) cutting process with multiresponse characteristics based on Multi Criteria Decision Making Methodology (MCDM) using the Technique for Order Preference by Similarity Ideal Solution (TOPSIS) approach. The process parameters water jet pressure, traverse rate, abrasive flow rate, and standoff distance are optimized with multiresponse characteristics, including the depth of penetration (DOP), cutting rate (CR), surface roughness (Ra), taper cut ratio (TCR), and top kerf width (TKW). The optimized results obtained from this approach indicate that higher DOP and CR and lower Ra, TCR, and TKW were achieved with combinations of the AWJ cutting process parameters, such as water jet pressure of 300MPa, traverse rate of 120mm/min, abrasive flow rate of 360 g/min, and standoff distance of 1mm. The experimental results indicate that the multiresponse characteristics of the AA5083-H32 unit used during the AWJ cutting process can be enhanced through the TOPSIS method. Analysis of variance was carried out to determine the significant factors for the AWJ cutting process.
The paper reports the experimental investigation of abrasive water jet (AWJ) cutting process on D... more The paper reports the experimental investigation of abrasive water jet (AWJ) cutting process on D2 steel varying the effect of jet impingement angles with different abrasive mesh sizes. The cutting performance parameters considered as the depth of penetration (DOP), material removal rate (MRR), surface roughness (Ra), and taper cut ratio (TCR). In this study, Taguchi experimental design was used to carry out the design of input process parameters and their levels. Scanning Electron Microscope (SEM) was used to study the surface morphology of the AWJ kerf wall cut surfaces. Finally, the result indicates that the influence of jet impingement angles and abrasive mesh sizes have dominating factors for the cutting of D2 steel by AWJ. The present study, suggests that improved cutting performance can be attained in AWJ, by changing the jet impingement angles and abrasive mesh sizes for the precise work conducted on AWJ.
In this paper, the optimization studies were carried out using grey relational analysis for the
a... more In this paper, the optimization studies were carried out using grey relational analysis for the
abrasive water jet (AWJ) cutting of AA5083 –H32 aluminum alloy with multi response characteristics. The water jet
pressure, mesh size of abrasives and impact angle are considered as input process parameters for the multi response
characteristics of AWJ cutting and the output responses are considered as depth of penetration (DOP), cutting rate
(CR), surface roughness (Ra), and taper cut ratio (TCR). The optimized results obtained from this approach,
indicates that higher DOP, CR and lower Ra, TCR, were achieved with optimal combinations of the AWJ cutting
process parameters, such as water jet pressure of 150 MPa, abrasive mesh size of #100 and impact angle of 80º
which have improved the quality of cutting. The experimental result indicates that the grey relational analysis has
enhanced the cutting performance of the AWJ cutting through the proper selection of process parameters for the
Aluminium alloy.
In High Speed Machining Processes, a major quality related output is surface roughness of the mac... more In High Speed Machining Processes, a major quality related output is surface roughness of the machined surfaces. Machining of the difficult-to-cut materials under high speed machining conditions results a drastic decrease in tool-life. Huge cutting force and higher cut edge temperature leads to poor surface finish. An attempt has been made in this paper to study the influence of cutting parameters on surface integrity of Inconel 718 nickel based super alloy under cryogenic cooling conditions during high speed machining. Experiments were carried out using Taguchi‟s L18 mixed orthogonal array based quality design concept to arrive the best optimal parametric combination by varying the cutting speed, feed, depth of cut, tool nose radius, air / LN2 pressure and the head level of LN2 in the cryocan. Analysis of variance (ANOVA) was done to find out the significance of the machining parameters while machining Inconel 718. Confirmation experiments were conducted to validate the experimental investigation.
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Papers by M.Pradeep Kumar
abrasive water jet (AWJ) cutting of AA5083 –H32 aluminum alloy with multi response characteristics. The water jet
pressure, mesh size of abrasives and impact angle are considered as input process parameters for the multi response
characteristics of AWJ cutting and the output responses are considered as depth of penetration (DOP), cutting rate
(CR), surface roughness (Ra), and taper cut ratio (TCR). The optimized results obtained from this approach,
indicates that higher DOP, CR and lower Ra, TCR, were achieved with optimal combinations of the AWJ cutting
process parameters, such as water jet pressure of 150 MPa, abrasive mesh size of #100 and impact angle of 80º
which have improved the quality of cutting. The experimental result indicates that the grey relational analysis has
enhanced the cutting performance of the AWJ cutting through the proper selection of process parameters for the
Aluminium alloy.
abrasive water jet (AWJ) cutting of AA5083 –H32 aluminum alloy with multi response characteristics. The water jet
pressure, mesh size of abrasives and impact angle are considered as input process parameters for the multi response
characteristics of AWJ cutting and the output responses are considered as depth of penetration (DOP), cutting rate
(CR), surface roughness (Ra), and taper cut ratio (TCR). The optimized results obtained from this approach,
indicates that higher DOP, CR and lower Ra, TCR, were achieved with optimal combinations of the AWJ cutting
process parameters, such as water jet pressure of 150 MPa, abrasive mesh size of #100 and impact angle of 80º
which have improved the quality of cutting. The experimental result indicates that the grey relational analysis has
enhanced the cutting performance of the AWJ cutting through the proper selection of process parameters for the
Aluminium alloy.