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Vedantha Krishna, AmoghORCID iD iconorcid.org/0000-0002-8364-202x
Publications (9 of 9) Show all publications
Reddy, V. V., Tam, P. L., Vedantha Krishna, A. & Rosén, B. G. (2019). Characterization of subsurface deformation of turned brasses: lead brass (CuZn39Pb3) and lead free brass (CuZn21Si3P). In: 16th International Conference on Metrology And Properties of Engineering Surfaces (Met And Props 2017): . Paper presented at 16th International Conference on Metrology and Properties of Engineering Surfaces (Met and Props), Gothenburg, Sweden, June 26-29, 2017. Bristol, UK: Institute of Physics Publishing (IOPP), Article ID 012006.
Open this publication in new window or tab >>Characterization of subsurface deformation of turned brasses: lead brass (CuZn39Pb3) and lead free brass (CuZn21Si3P)
2019 (English)In: 16th International Conference on Metrology And Properties of Engineering Surfaces (Met And Props 2017), Bristol, UK: Institute of Physics Publishing (IOPP), 2019, article id 012006Conference paper, Published paper (Refereed)
Abstract [en]

The adverse effects of lead on human health and the recycling problems of copper alloys with lead content has led to the increase in concern for reducing/eliminating the use of lead in brass and other copper alloys. The real challenge prevails in sustainable manufacturing of lead free brass and to maintain as well as control the surface integrity when lead is substituted in the brass with silicon. This article is part of the study that focuses on characterizing the surface integrity of machined lead brass and lead free brass. This paper deals with the study of surface layer characteristics of brass samples, investigating the subsurface deformation influenced by the turning operation. It is important to study the plastic deformation under the machined surface which directly affects the performance of the material on further machining or application. In this study, metallographic investigations are performed on turned samples of lead brass and lead free brass and include comparisons between the study samples based on the plastic deformations quantified by grain orientations and microhardness measurements. The study performed successfully characterizes the subsurface deformation and the results suggest slightly higher subsurface deformation in turned lead brass as compared to lead free brass.

Place, publisher, year, edition, pages
Bristol, UK: Institute of Physics Publishing (IOPP), 2019
Series
Journal of Physics Conference Series, ISSN 1742-6588 ; 1183
National Category
Other Materials Engineering
Identifiers
urn:nbn:se:hh:diva-41469 (URN)10.1088/1742-6596/1183/1/012006 (DOI)000487359400006 ()2-s2.0-85067787405 (Scopus ID)
Conference
16th International Conference on Metrology and Properties of Engineering Surfaces (Met and Props), Gothenburg, Sweden, June 26-29, 2017
Available from: 2020-01-31 Created: 2020-01-31 Last updated: 2020-02-07Bibliographically approved
Vedantha Krishna, A., Flys, O., Reddy, V. V., Leicht, A., Hammar, L. & Rosén, B. G. (2018). Potential approach towards effective topography characterization of 316L stainless steel components produced by selective laser melting process. In: European Society for Precision Engineering and Nanotechnology, Conference Proceedings - 18th International Conference and Exhibition, EUSPEN 2018: . Paper presented at Euspen’s 18th International Conference & Exhibition, Venice, Italy, 4th-8th June, 2018 (pp. 259-260). Bedford: euspen
Open this publication in new window or tab >>Potential approach towards effective topography characterization of 316L stainless steel components produced by selective laser melting process
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2018 (English)In: European Society for Precision Engineering and Nanotechnology, Conference Proceedings - 18th International Conference and Exhibition, EUSPEN 2018, Bedford: euspen , 2018, p. 259-260Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

In this paper, an attempt is made to explain the surface texture of Selective Laser Melting (SLM) parts more satisfyingly than the existing methods. Investigations were carried out on the 316L stainless steel SLM samples. To account for most of the surface conditions, a truncheon artefact was employed for the analysis. A Stylus Profilometer was employed as a metrology tool for obtaining the 3D surface measurements. A methodology is proposed to extract and characterize the topographic features of Additive Manufactured (AM) surfaces. Here, the overall roughness of the surface is segregated into the roughness of the powder particles and the waviness due to thermal and the “staircase” effects. Analyzing these features individually results in an increased understanding of the AM process and an opportunity to optimize machine settings.

Place, publisher, year, edition, pages
Bedford: euspen, 2018
Keywords
Surface Metrology, Selective Laser Melting, Profilometer, Areal Surface Parameters, Feature-based characterization
National Category
Materials Engineering
Identifiers
urn:nbn:se:hh:diva-38126 (URN)2-s2.0-85054549685 (Scopus ID)9780995775121 (ISBN)0995775125 (ISBN)
Conference
Euspen’s 18th International Conference & Exhibition, Venice, Italy, 4th-8th June, 2018
Available from: 2018-10-09 Created: 2018-10-09 Last updated: 2019-01-08Bibliographically approved
Reddy, V. V., Flys, O., Chaparala, A., Berrimi, C. E., Vedantha Krishna, A. & Rosén, B. G. (2018). Study on surface texture of Fused Deposition Modeling. In: Mauro Onori, Lihui Wang, Xi Vincent Wang, Wei Ji (Ed.), Proceedings of the 8th Swedish Production Symposium (SPS 2018): . Paper presented at 8th Swedish Production Symposium, SPS 2018, Stockholm, Sweden, 16-18 May, 2018 (pp. 389-396). Amsterdam: Elsevier, 25
Open this publication in new window or tab >>Study on surface texture of Fused Deposition Modeling
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2018 (English)In: Proceedings of the 8th Swedish Production Symposium (SPS 2018) / [ed] Mauro Onori, Lihui Wang, Xi Vincent Wang, Wei Ji, Amsterdam: Elsevier, 2018, Vol. 25, p. 8p. 389-396Conference paper, Published paper (Refereed)
Abstract [en]

Fused Deposition Modeling (FDM) is mostly used to develop functional prototypes and in some applications for end-use parts. It is important to study the surfaces produced by FDM to understand the certainty of process. Truncheon design test artefacts are printed at different print settings and surfaces are measured using stylus profilometer. Taguchi’s design of experiments, signal-to-noise ratio and multiple regression statistics are implemented to establish a concise study of the individual and combined effect of process variables on surface texture parameters. Further, a model is developed to predict the roughness parameters and is compared with experimental values. The results suggest significant roughness parameter values decrease with increase in build inclination and increases with increase in layer thickness except the roughness peak count. © 2018 The Authors. Published by Elsevier B.V

Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2018. p. 8
Series
Procedia Manufacturing, E-ISSN 2351-9789 ; 25
Keywords
Additive manufacturing, Fused Deposition Modeling, Surface texture parameters, Surface roughness
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:hh:diva-38122 (URN)10.1016/j.promfg.2018.06.108 (DOI)2-s2.0-85060107757 (Scopus ID)
Conference
8th Swedish Production Symposium, SPS 2018, Stockholm, Sweden, 16-18 May, 2018
Projects
Digitalization of the supply chain of the Swedish Additive Manufacturing (DiSAM)Business Model Innovation
Funder
VINNOVAKnowledge Foundation
Note

Funding: VINNOVA, Sweden’s innovation agency and Produktion2030 under the project Digitalization of the supply chain of the Swedish Additive Manufacturing (DiSAM) and Sweden’s The Knowledge Foundation under the project Business Model Innovation when adapting to Digital Production - opportunities and problems.

Available from: 2018-10-09 Created: 2018-10-09 Last updated: 2020-02-03Bibliographically approved
Vedantha Krishna, A., Flys, O., Reddy, V. V. & Rosén, B. G. (2018). Surface topography characterization using 3D stereoscopic reconstruction of SEM images. Surface Topography: Metrology and Properties, 6(2), Article ID 024006.
Open this publication in new window or tab >>Surface topography characterization using 3D stereoscopic reconstruction of SEM images
2018 (English)In: Surface Topography: Metrology and Properties, ISSN 2051-672X, Vol. 6, no 2, article id 024006Article in journal (Refereed) Published
Abstract [en]

A major drawback of the optical microscope is its limitation to resolve finer details. Many microscopes have been developed to overcome the limitations set by the diffraction of visible light. The scanning electron microscope (SEM) is one such alternative: it uses electrons for imaging, which have much smaller wavelength than photons. As a result high magnification with superior image resolution can be achieved. However, SEM generates 2D images which provide limited data for surface measurements and analysis. Often many research areas require the knowledge of 3D structures as they contribute to a comprehensive understanding of microstructure by allowing effective measurements and qualitative visualization of the samples under study. For this reason, stereo photogrammetry technique is employed to convert SEM images into 3D measurable data. This paper aims to utilize a stereoscopic reconstruction technique as a reliable method for characterization of surface topography. Reconstructed results from SEM images are compared with coherence scanning interferometer (CSI) results obtained by measuring a roughness reference standard sample. This paper presents a method to select the most robust/consistent surface texture parameters that are insensitive to the uncertainties involved in the reconstruction technique itself. Results from the two-stereoscopic reconstruction algorithms are also documented in this paper. © 2018 IOP Publishing Ltd.

Place, publisher, year, edition, pages
Bristol: Institute of Physics (IOP), 2018
Keywords
Image resolution, Interferometers, Light, Photogrammetry, Power spectral density, Scanning, Scanning electron microscopy, Spectral density, Stereo image processing, Surface measurement, Surface topography, Three dimensional computer graphics, High magnifications, Reconstruction algorithms, Reconstruction techniques, Reference standard samples, Scanning interferometers, Stereophotogrammetry, Surface texture parameters, The scanning electron microscopes (SEM), Image reconstruction
National Category
Computer Vision and Robotics (Autonomous Systems)
Identifiers
urn:nbn:se:hh:diva-38710 (URN)10.1088/2051-672X/aabde1 (DOI)000432445700001 ()2-s2.0-85051421851 (Scopus ID)
Available from: 2019-01-08 Created: 2019-01-08 Last updated: 2020-03-02Bibliographically approved
Reddy, V. V., Tam, P. L., Vedantha Krishna, A. & Rosén, B. G. (2017). Subsurface Characterization of Turned Brass alloys using Backscattered Electron Microscopy. In: Mets&Props 2017: 16th International Conference on Metrology and Properties of Engineering Surfaces: Conference abstracts. Paper presented at 16th International Conference on Metrology and Properties of Engineering Surfaces, Gothenburg, Sweden, June 27-29, 2017 (pp. 14-15).
Open this publication in new window or tab >>Subsurface Characterization of Turned Brass alloys using Backscattered Electron Microscopy
2017 (English)In: Mets&Props 2017: 16th International Conference on Metrology and Properties of Engineering Surfaces: Conference abstracts, 2017, p. 14-15Conference paper, Oral presentation with published abstract (Refereed)
Keywords
Surface Integrity, Subsurface deformation, Grain analysis, Grain Orientation, Scanning Electron Microscope
National Category
Materials Engineering
Identifiers
urn:nbn:se:hh:diva-35174 (URN)
Conference
16th International Conference on Metrology and Properties of Engineering Surfaces, Gothenburg, Sweden, June 27-29, 2017
Projects
Lead free Brass
Funder
Mistra - The Swedish Foundation for Strategic Environmental Research
Available from: 2017-10-10 Created: 2017-10-10 Last updated: 2017-10-27Bibliographically approved
Reddy, V. V., Vedantha Krishna, A., Schultheiss, F. & Rosén, B. G. (2017). Surface topography characterization of brass alloys: lead brass (CuZn39Pb3) and lead free brass (CuZn21Si3P). Surface Topography: Metrology and Properties, 5(2), Article ID 025001.
Open this publication in new window or tab >>Surface topography characterization of brass alloys: lead brass (CuZn39Pb3) and lead free brass (CuZn21Si3P)
2017 (English)In: Surface Topography: Metrology and Properties, ISSN 2051-672X, Vol. 5, no 2, article id 025001Article in journal (Refereed) Published
Abstract [en]

Manufactured surfaces usually consist of topographical features which include both those put forth by the manufacturing process, and micro-features caused by disturbances during this process. Surface characterization basically involves study of these features which influence the functionality of the surface. This article focuses on characterization of the surface topography of machined lead brass and lead free brass. The adverse effect of lead on human health and the environment has led the manufacturing sector to focus on sustainable manufacturing of lead free brass, as well as how to maintain control of the surface integrity when substituting the lead content in the brass with silicon. The investigation includes defined areal surface parameters measured on the turned samples of lead- and lead free brass using an optical coherence scanning interferometer, CSI. This paper deals with the study of surface topography of turned samples of lead-and lead free brass. It is important to study the topographical characteristics of the brass samples which are the intermediate link between the manufacturing process variables and the functional behaviour of the surface. To numerically evaluate the sample's surface topography and to validate the measurements for a significant study, a general statistical methodology is implemented. The results indicate higher surface roughness in turned samples of lead brass compared to lead free brass. © 2017 IOP Publishing Ltd

Place, publisher, year, edition, pages
Bristol: Institute of Physics Publishing (IOPP), 2017
Keywords
areal surface parameters, optical interferometer, multiple regression analysis, surface topography, lead free brass, surface roughness
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Identifiers
urn:nbn:se:hh:diva-35600 (URN)10.1088/2051-672X/aa612b (DOI)000398423900001 ()2-s2.0-85020298117 (Scopus ID)
Available from: 2017-12-04 Created: 2017-12-04 Last updated: 2018-01-13Bibliographically approved
Vedantha Krishna, A., Flys, O., Reddy, V. V. & Rosén, B.-G. (2017). Surface topography characterization using 3D stereoscopic reconstruction of SEM images. In: Mets&Props 2017: Mets&Props 2017: 16th International Conference on Metrology and Properties of Engineering Surfaces: Conference abstracts, 2017. Paper presented at 16th International Conference on Metrology and Properties of Engineering Surfaces, Gothenburg, Sweden, June 27-29, 2017 (pp. 219-221).
Open this publication in new window or tab >>Surface topography characterization using 3D stereoscopic reconstruction of SEM images
2017 (English)In: Mets&Props 2017: Mets&Props 2017: 16th International Conference on Metrology and Properties of Engineering Surfaces: Conference abstracts, 2017, 2017, p. 219-221Conference paper, Oral presentation with published abstract (Refereed)
Keywords
Scanning Electron Microscope, Coherence Scanning Interferometer, Stereoscopic Reconstruction, Power Spectral Density, Areal Surface Texture Parameters
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Identifiers
urn:nbn:se:hh:diva-35173 (URN)
Conference
16th International Conference on Metrology and Properties of Engineering Surfaces, Gothenburg, Sweden, June 27-29, 2017
Available from: 2017-10-10 Created: 2017-10-10 Last updated: 2018-03-23Bibliographically approved
Reddy, V. V., Flys, O., Vedantha Krishna, A. & Rosén, B. G. (2017). Topography characterization of fused deposition modelling surfaces. In: European Society for Precision Engineering and Nanotechnology- SIG Additive manufacturing Proceedings 2017: . Paper presented at Joint Special Interest Group meeting between euspen and ASPE Dimensional Accuracy and Surface Finish in Additive Manufacturing, KU Leuven, Leuven, Belgium, 10-11 October, 2017. Bedford: Euspen
Open this publication in new window or tab >>Topography characterization of fused deposition modelling surfaces
2017 (English)In: European Society for Precision Engineering and Nanotechnology- SIG Additive manufacturing Proceedings 2017, Bedford: Euspen , 2017Conference paper, Published paper (Refereed)
Abstract [en]

Deemed as one of the established additive manufacturing technique, fused deposition modelling (FDM) is commonly used for creating functional prototypes. Additive manufacturing, in general, generates surfaces that are different compared to conventional manufacturing and consists of features that are either not well-defined or satisfactorily characterized using the existing surface standards. The generated surfaces vary with respect to different techniques, materials, geometries and process parameters Additive manufacturing boosts of manufacturing individualized parts and as claimed, product with complex design can be easily manufactured but the problem lies in manufacturing it with highest surface quality or produce a well-defined robust surface. The aim of the study is to characterize the FDM surfaces generated at different process settings using areal surface parameters. The experimental study includes surface measurements of study sample build at different orientation and layer thickness. A general statistical methodology is implemented to identify the deterministic features on the manufactured surface. The results include topography characterization using the significant features and detailed study on the influence of geometry and process settings on FDM surfaces.

Place, publisher, year, edition, pages
Bedford: Euspen, 2017
Keywords
Additive manufacturing (AM), Fused Deposition Modelling (FDM), Surface Topography, Areal surface parameters
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:hh:diva-41967 (URN)
Conference
Joint Special Interest Group meeting between euspen and ASPE Dimensional Accuracy and Surface Finish in Additive Manufacturing, KU Leuven, Leuven, Belgium, 10-11 October, 2017
Available from: 2020-04-25 Created: 2020-04-25 Last updated: 2020-05-15
Reddy, V. V., Vedantha Krishna, A., Schultheiss, F. & Rosén, B. G. (2016). Lead free Brass: Topography Characterization. In: : . Paper presented at 7th Swedish Production Symposium, Lund, Sweden, October 25th-27th, 2016.
Open this publication in new window or tab >>Lead free Brass: Topography Characterization
2016 (English)Conference paper, Oral presentation only (Refereed)
Abstract [en]

The negative effects of lead on human health and the recycling problems of copper alloys with lead content has led to the increase in concern for reducing/eliminating the use of lead in brass and other copper alloys. Many materials are considered to replace lead in brass; silicon is one such alternative. The real challenge prevails in sustainable manufacturing of lead free brass, to maintain control of the surface integrity when substituting the lead content in the brass with silicon. The investigation includes defined areal surface parameters measured on the turned samples of lead- and lead free brass using an optical coherence scanning interferometer, CSI.This paper deals with the study of surface topography of turned samples of lead and lead free brass. It is important to study the topographical characteristics of the brass samples which are the intermediate link between the manufacturing process variables and the functional behaviour of the surface. To numerically evaluate the sample’s surface topography and to validate the measurements for a significant study, a general statistical methodology is implemented. The results suggest that the surface roughness is higher in lead brass compared to lead free brass and tool coatings have significant influence on the hybrid (Sdr & Sdq) parameters in the surface topography of brass samples.

Keywords
Lead free Brass, Surface Topography, Areal Surface Parameters, Mountains Map, Regression Analysis, Optical Interferometer
National Category
Materials Engineering Mechanical Engineering
Identifiers
urn:nbn:se:hh:diva-32715 (URN)
Conference
7th Swedish Production Symposium, Lund, Sweden, October 25th-27th, 2016
Projects
Lead free Copper alloys
Funder
Mistra - The Swedish Foundation for Strategic Environmental Research
Note

Funding: MISTRA, The Swedish Foundation for Strategic Environmental Research, as well as the Swedish Strategic Innovation Area, SIO: Produktion2030.

Available from: 2016-12-15 Created: 2016-12-15 Last updated: 2017-10-27Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-8364-202x

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