Emissivity calibration for temperatures measurement using thermography in the context of machining

Valiorgue, Frédéric; Brosse, Alexandre; Naisson, Pierre; Rech, J.; Hamdi, Hédi; Bergheau, Jean‐Michel

doi:10.1016/j.applthermaleng.2013.03.051

Cited by 53 publications

(18 citation statements)

References 14 publications

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“…The dimensioning of the thermographic line depends on the expected thermal range. Recent works, in the field of orthogonal cutting [5,59], with different cutting conditions (speed, angle and material), provides a glance at the expected temperature range of T min = 200 • C to T max = 550 • C. In order to choose the most suited detector, it is classical to refer to the cross-checking of Planck's laws calculated at the two extremes temperatures of the range (Eq.1). Indeed, for a blackbody at a given temperature, 95% of the emitted flux is between 0.5λ max and 5λ max , where λ max is provided by Wien's displacement law.…”

Section: Imaging Apparatusmentioning

confidence: 99%

“…It allowed the measurement of temperature fields with a resolution of 10µm/pixel and an exposure time of 2ms, at a cutting speed of 400m/min. Others authors have developed various experimental apparatus to obtain temperature fields at high cutting speeds (above 100m.min −1 ) for continuous chips [54,18,32,59,5]. At such cutting speed, the scale of the problem imposes to use high exposure time, therefore, the obtained images are blurred (time-convoluted) and can thus only be processed when a thermal steady state is reached.…”

Section: Introductionmentioning

confidence: 99%

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A coupled in-situ measurement of temperature and kinematic fields in Ti-6Al-4V serrated chip formation at micro-scale

Harzallah

Pottier

Gilblas

et al. 2018

International Journal of Machine Tools and Manufacture

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The present paper describes and uses a novel bi-spectral imaging apparatus dedicated to the simultaneaous measurement of kinematic and thermal fields in orthogonal cutting experiment. Based on wavelength splitting, this device is used to image small scale phenomenon (about 500×500µm area) involved in the generation of serrated chips from Ti-6Al-4V titanium alloy. Small to moderate cutting speeds are investigated at 6000 images per second for visible spectrum and 600 images per second for infrared measuresments. It allows to obtain unblurred images. A specific attention is paid to calibration issue including optical distortion correction, thermal calibration and data mapping. A complex post-processing procedure based on DIC and direct solution of the heat diffusion equation is detailed in order to obtain strain, strain-rate, temperature and dissipation fields from raw data in a finite strains framework. Finally a discussion is addressed and closely analyzes the obtained results in order to improve the understanding of the segment generation problem from a kinemtatic standpoint but also for the first time from an energetic standpoint.

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Section: Imaging Apparatusmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A coupled in-situ measurement of temperature and kinematic fields in Ti-6Al-4V serrated chip formation at micro-scale

Harzallah

Pottier

Gilblas

et al. 2018

International Journal of Machine Tools and Manufacture

View full text Add to dashboard Cite

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“…However, changes in the emission coefficient from the surface may significantly influence the applied temperature. 4,[5][6][7][8] A solution to this is to pre-oxidise the specimen in order to produce a stable oxide layer. 9 Preexposure of this kind requires careful consideration as this additional heat treatment may be detrimental to fatigue life in some alloys.…”

Section: Introductionmentioning

confidence: 99%

“…13 Previous work has shown the IRT technique to be successful at monitoring temperature of an entire area. 7,8,[14][15][16] The current paper seeks to document attempts to implement an IRT for temperature monitoring and control purposes during mechanical testing, temperature response is compared to TCs and a pyrometer. The technique is used in combination with Rolls-Royce HE23 thermal paint (TP) to stabilise effects of emissivity and highlight the benefits of both a known emissivity and accurate control of temperature over a larger region of the test piece.…”

Section: Introductionmentioning

confidence: 99%

Non-invasive temperature measurement and control techniques under thermomechanical fatigue loading

Jones

Brookes

Whittaker

et al. 2014

Materials Science and Technology

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A non-invasive temperature measurement, control and profiling technique has been investigated for use with thermomechanical fatigue loading. The technique utilises an infrared thermography camera and Rolls-Royce developed thermal paint to control and monitor cyclic temperature. Thermal paint is used to maintain a stable surface emissivity upon the test piece. The accuracy of the technique is compared against type N thermocouples and a pyrometer for both temperature control and monitoring purposes. Diverse test specimen geometries and alloy compositions are used over a 100-700uC temperature range. Effects on temperature measurement accuracy such as thermocouple shadowing are highlighted and quantified. The non-invasive technique has proved accurate to within ¡2uC of the reference thermocouples when in combination with the thermal paint coating.

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“…Recent studies have focused on finding methods to measure emissivity and also quantify uncertainty due to emissivity infra-red temperature measurements which will further aid the development of radiation thermometry [34,35]. Another interesting avenue is work that has been carried out by Herve et al is in the development of simultaneous temperature and emissivity measurement [36].…”

Section: Emissivitymentioning

confidence: 99%

Identification of Key Temperature Measurement Technologies for the Enhancement of Product and Equipment Integrity in the Light Controlled Factory

Ross-Pinnock

Maropoulos

2014

Procedia CIRP

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Thermal effects in uncontrolled factory environments are often the largest source of uncertainty in large volume dimensional metrology. As the standard temperature for metrology of 20˚C cannot be achieved practically or economically in many manufacturing facilities, the characterisation and modelling of temperature offers a solution for improving the uncertainty of dimensional measurement and quantifying thermal variability in large assemblies.Technologies that currently exist for temperature measurement in the range of 0-50˚C have been presented alongside discussion of these temperature measurement technologies' usefulness for monitoring temperatures in a manufacturing context. Particular aspects of production where the technology could play a role are highlighted as well as practical considerations for deployment.Contact sensors such as platinum resistance thermometers can produce accuracy closest to the desired accuracy given the most challenging measurement conditions calculated to be ~0.02˚C. Non-contact solutions would be most practical in the light controlled factory (LCF) and semi-invasive appear least useful but all technologies can play some role during the initial development of thermal variability models. Main textIn large volume metrology, thermal effects make a significant contribution to the uncertainty of measurements. Large structures that are often 20 m in length or greater are currently being assembled in factory environments where there can be thermal gradients of around 3-5˚C from floor to ceiling at any given time. Over a 24 hour cycle, the variation in ambient temperature can be as much as 15˚C.Whilst dimensional measurements in industry are sometimes taken alongside ambient temperature measurements which are used for linear scaling within the metrology software, this is often a sole measurement at one point in space, at one instance.One potential solution to the problem of thermally induced uncertainty is to model the thermal characteristics of the measurand. This can be achieved by monitoring the temperature and using this data to update a computational model that can more accurately predict the thermal and gravitational effects of the environment. The computational model makes use of the nominal CAD geometry of the measurand, alongside finite element analysis and tolerancing software.

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Emissivity calibration for temperatures measurement using thermography in the context of machining

Cited by 53 publications

References 14 publications

A coupled in-situ measurement of temperature and kinematic fields in Ti-6Al-4V serrated chip formation at micro-scale

A coupled in-situ measurement of temperature and kinematic fields in Ti-6Al-4V serrated chip formation at micro-scale

Non-invasive temperature measurement and control techniques under thermomechanical fatigue loading

Identification of Key Temperature Measurement Technologies for the Enhancement of Product and Equipment Integrity in the Light Controlled Factory

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