Suche nach „[O.] [Fähnle]“ hat 24 Publikationen gefunden

NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenIPH Teisnach

Beitrag (Sammelband oder Tagungsband)

Michael Benisch, O. Fähnle, Rolf Rascher

Observation of pressure distribution between tool and surface in different polishing situations

Proceedings of SPIE Optical Engineering + Applications (24 August - 04 September, 20208; Optical Manufacturing and Testing XIII; online conference), San Diego, United States, vol. 11487

2020

DOI: 10.1117/12.2567885

Abstract anzeigen

Pressure is a relevant parameter in the polishing of components according to the Preston equation.1, 2 Preliminary investigations have shown that the pressure can vary with inclined position and different polishing pads. It is not constant with regard to its distribution in the contact area between polishing pad and glass surface. In this publication, the pressure distribution during the polishing of glass components is analyzed. For the measurement of the pressure distribution a pressure sensitive foil is used.

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Beitrag (Sammelband oder Tagungsband)

Michael Benisch, Christian Vogt, Rolf Rascher, O. Fähnle

Octopus: A simple and effective tool for polishing slurry monitoring

Proceedings of SPIE Optical Engineering + Applications (24 August - 04 September, 20208; Optical Manufacturing and Testing XIII; online conference), San Diego, United States, vol. 11487

2020

DOI: 10.1117/12.2567952

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The present paper shows a way for a cost-effective, integrated measurement of the density p of polishing suspensions. It is based on the principle of measuring the turbidity of a solution on the basis of the light transmitted through it, and of calculating back to the density on the basis of the turbidity. The tool is suitable for monitoring polishing agents and for detecting when the density of the polishing slurry leaves the permissible parameter space and can perspectively enable the automated monitoring and adjustment of polishing suspensions. The tool is named after an Octopus. These animals have amazing abilities, for example they can copy the behaviour of other sea animals or act with a plan. Their tentacles each have their own brain and can perform biochemical analyses.

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Beitrag (Sammelband oder Tagungsband)

Michael Benisch, O. Fähnle, Rolf Rascher

Application of a pressure measuring film for pressure observation in overarm polishing

Proceedings of EOSAM 2020 (European Optical Society Biennial Meeting; 7-11 September 2020; online), vol. 238

2020

DOI: 10.1051/epjconf/202023803003

Abstract anzeigen

In previous publications the inhomogeneous pressure transfer through the polishing tool onto a glass surface could be shown. This experiment shows polishing trials with different polishing materials and the differences in the homogeneity of the pressure transfer through them. Only the properties of the material will be discussed explicitly, the change of the tool constitution through the process will be part of further publications.

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Beitrag (Sammelband oder Tagungsband)

Michael Benisch, O. Fähnle, Rolf Rascher, Werner Bogner

Force and pressure analysis during overarm polishing

Proceedings of SPIE 11478 (Seventh European Seminar on Precision Optics Manufacturing [8 July 2020; Teisnach]), Bellingham, WA, USA

2020

DOI: 10.1117/12.2564903

Abstract anzeigen

The Preston-equation implies, that, besides the relative speed υrel and a specific constant KP, the pressure p plays a significant role for the removal rate when polishing an optical component. This paper demonstrates a possibility for a qualitative evaluation of the pressure distribution before the polishing process. A pressure-sensitive foil is used as a gauge for pressure measurement. The effectiveness of this measuring method is explained. Specific weaknesses and limitations in the use of these foils are discussed. A method for an integrated evaluation of the pressure on different spots of the polishing pad is proposed at the end of the paper.

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Beitrag (Sammelband oder Tagungsband)

M. Doetz, O. Dambon, Christian Vogt, Rolf Rascher, E. Langenbach, O. Fähnle

Enlarging process window of ductile mode machining of WC molds

Proceedings of EOSAM 2018 (European Optical Society Biennial Meeting; October 2018; Delft, The Netherlands): Optical System Design, Tolerancing, and Fabrication

2018

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Beitrag (Sammelband oder Tagungsband)

Christian J. Trum, Christian Vogt, O. Fähnle, Sebastian Sitzberger, Rolf Rascher

First experiences with Filled-Up-Microscopy (FUM) to evaluate the depth of sub-surface damages on ground surfaces

Proceedings of EOSAM 2018 (European Optical Society Biennial Meeting; October 2018; Delft, The Netherlands): Optical System Design, Tolerancing, and Fabrication

2018

DigitalNachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenIPH Teisnach

Beitrag (Sammelband oder Tagungsband)

Christian Vogt, M. Doetz, Rolf Rascher, O. Fähnle

Standardized evaluation of grinding tools for brittle and ductile mode grinding

Invited Paper

Proceedings of EOSAM 2018 (European Optical Society Biennial Meeting; October 2018; Delft, The Netherlands): Optical System Design, Tolerancing, and Fabrication

2018

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Vortrag

Rolf Rascher, Christian Vogt, O. Fähnle, E. Langenbach

Closed-loop laser polishing of glass

LaP 2018 - 3rd Conference on Laser Polishing, Aachen

2018

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Beitrag (Sammelband oder Tagungsband)

Christian Vogt, O. Fähnle, E. Langenbach, Rolf Rascher

In situ monitoring of laser polishing

DGaO-Proceedings 2018

2018

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Beitrag (Sammelband oder Tagungsband)

O. Fähnle, Christian Vogt, Rolf Rascher

Load controlled process window analysis of feed controlled CNC grinding

PROCEEDINGS VOLUME 10692 SPIE OPTICAL SYSTEMS DESIGN, 14-17 MAY 2018 Optical Fabrication, Testing, and Metrology VI, Frankfurt, Germany

2018

ISBN: 978-1-5106-1921-0

DOI: 10.1117/12.2315336

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Beitrag (Sammelband oder Tagungsband)

O. Fähnle, O. Dambon, M. Doetz, F. Klocke, Christian Vogt, Rolf Rascher

Ductile grinding of tungsten carbide applying standard CNC machines: a process analysis

Proceedings of SPIE 10692: SPIE Optical Systems Design/Optical Fabrication, Testing, and Metrology VI (14.-17.05.2018; Frankfurt/Main)

2018

DOI: 10.1117/12.2315338

NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenIPH Teisnach

Beitrag (Sammelband oder Tagungsband)

Christian J. Trum, Christian Vogt, Sebastian Sitzberger, Rolf Rascher, O. Fähnle

Filled-Up-Microscopy (FUM): a non-destructive method for approximating the depth of sub-surface damage on ground surfaces

Proceedings of SPIE 10829 (Fifth European Seminar on Precision Optics Manufacturing [April 10-11, 2018; Teisnach])

2018

ISBN: 978-1-5106-2270-8

DOI: 10.1117/12.2318576

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Beitrag (Sammelband oder Tagungsband)

O. Fähnle, M. Doetz, O. Dambon, F. Klocke, Christian Vogt, Rolf Rascher

Ductile mode single point diamond turning (SPDT) of binderless tungsten carbide molds

Proceedings of SPIE Optical Engineering + Applications (19-23 August, 2018; Optical Manufacturing and Testing XII; San Diego, CA, USA), San Diego, United States, vol. 10742

2018

ISBN: 978-1-5106-2055-1

DOI: 10.1117/12.2323244

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Beitrag (Sammelband oder Tagungsband)

O. Fähnle, Christian Vogt, Rolf Rascher, M. Doetz, O. Dambon, F. Klocke

From turning to grinding: ductile machining with gPVA

Proceedings of SPIE Optical Engineering + Applications (19-23 August, 2018; Optical Manufacturing and Testing XII; San Diego, CA, USA), San Diego, United States, vol. 10742

2018

ISBN: 978-1-5106-2055-1

DOI: 10.1117/12.2323246

NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenIPH Teisnach

Beitrag (Sammelband oder Tagungsband)

O. Fähnle, Christian Vogt, Rolf Rascher, M. Doetz, O. Dambon, F. Klocke

Ductile grinding of tungsten carbide molds applying standard CNC machines

Proceedings of SPIE Optical Engineering + Applications (19-23 August, 2018; Optical Manufacturing and Testing XII; San Diego, CA, USA), San Diego, United States, vol. 10742

2018

ISBN: 978-1-5106-2055-1

DOI: 10.1117/12.2323245

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Beitrag (Sammelband oder Tagungsband)

Christian Vogt, Rolf Rascher, O. Fähnle, Dae Kim

Closed-loop next generation laser polishing

Proceedings of SPIE 10829 (Fifth European Seminar on Precision Optics Manufacturing [April 10-11, 2018; Teisnach])

2018

ISBN: 978-1-5106-2270-8

DOI: 10.1117/12.2318749

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Beitrag (Sammelband oder Tagungsband)

M. Doetz, O. Fähnle, Christian Vogt

SPDT and standard CNC-grinding of tungsten carbide molds for precision glass molding: an experimental process analysis

Proceedings of SPIE 10829 (Fifth European Seminar on Precision Optics Manufacturing [April 10-11, 2018; Teisnach])

2018

ISBN: 978-1-5106-2270-8

DOI: 10.1117/12.2318710

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Beitrag (Sammelband oder Tagungsband)

Christian Vogt, O. Fähnle, Rolf Rascher

gPVA: a system for the classification of grinding tools

Proceedings of SPIE 10829 (Fifth European Seminar on Precision Optics Manufacturing [April 10-11, 2018; Teisnach])

2018

ISBN: 978-1-5106-2270-8

DOI: 10.1117/12.2318695

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Vortrag

Christian Vogt, O. Fähnle, E. Langenbach, Rolf Rascher

In situ laser monitoring of laser polishing

119. Jahrestagung der Deutschen Gesellschaft für angewandte Optik (DGaO), Technische Hochschule Aalen

2018

Abstract anzeigen

A novel fabrication parameter controlling method for laser polishing is presented, measuring within the footprint the smoothening process in real time. Recently, a new method for in situ measuring level of surface roughness has been developed [1] where a HeNe laser beam is being reflected from within the sample at the surface under test and the intensity of its reflected beam is being monitored.In this paper we report on an experimental study where this method has been applied to laser polishing. The internal local surface area under test is chosen to be located at the very spot where the laser polishing footprint is located from the outside of the sample melting its surface locally. Because fused silica is not transparent at the operating CO2 laser wavelength, the intensity of the reflected beam can be monitored enabling an in situ control of the laser polishing process. Consequently, the optimum dwell time can be determined, a footprint needs to stay at a certain point before moving further enabling a more stable and cost optimized polishing. [1] O.Fähnle,“In process monitoring of optics fabrication”, SPIEconference “PrecisionOptics Manufacturing”2017

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Zeitschriftenartikel

O. Fähnle, Rolf Rascher, Christian Vogt, D.W. Kim

Closed-loop laser polishing using in-process surface finish metrology

Applied Optics, vol. 57, no. 4, pp. 834-838

2018

DOI: 10.1364/AO.57.000834

Abstract anzeigen

This paper lays out the trail onto a closed-loop polishing process of optical elements enabling the application of the optimum polishing time needed. To that aim, an in-process testing method for monitoring an inclusive micro surface quality (e.g., comprising surface roughness and scratch-and-dig) within the polishing spot is analyzed and its applicability to closed-loop polishing for classical loose-abrasive full-aperture polishing as well as for computer controlled laser polishing is experimentally tested and verified. This enables the determination of the optimum local dwell time resulting in a stable and cost optimized polishing.