caa a22 4500 445370696 CHVBK 20180317142945.0 cr unu---uuuuu 170323e20111101xx s 000 0 eng 10.1007/s00340-011-4611-3 doi (NATIONALLICENCE)springer-10.1007/s00340-011-4611-3 Application of optical pyrometry for on-line monitoring in laser-cutting technologies [Elektronische Daten] [A. Dubrov, V. Dubrov, Y. Zavalov, V. Panchenko] The results of measurement of fluctuations of brightness temperatureT in the region of exposure to laser radiation of a 3mm-thick steel plate are presented. The local luminosity along the cut-front was measured using two-color multichannel pyrometer. Cutting trials were carried out with CO2 laser (10.6μm, 1200W) and fiber laser (1.07μm, 1800W). Special attention was given to the frequency range of temperature fluctuations above frequency of melt overflight, aiming on on-line monitoring applications. It is shown that local fluctuations of T are related to local melt's surface deformations due to unequal radiation absorption; thus the noise spectrum of T fluctuations reflects turbulent surface deformation, caused by gas jet and capillary waves. It is also shown that the thermo-capillary effect with capillary-wave turbulence generation can be observed in case of exposure to 10.6μm radiation with a laser intensity of about 1MW/cm2. The power law of "−7/6” describes the spectrum of the T fluctuation variance in this case of anomalous absorption of radiation, and the standard deviation of T is in excess of 10K for a frequency of 14kHz. There is no such effect in case of fiber-laser radiation applying, and the source of the capillary waves is only forced low-frequency deformations of the melt surface. The standard deviation of T does not exceed 3K on the frequency of 14kHz, and above, and a power law of the spectrum fluctuation is described by about "−3” in that range. Springer-Verlag, 2011 Dubrov A. Institute on Laser and Information Technology of Russian Academy of Science, 1 Svyatoozerskaya st., 140700, Shatura, Moscow Region, Russia aut Dubrov V. Institute on Laser and Information Technology of Russian Academy of Science, 1 Svyatoozerskaya st., 140700, Shatura, Moscow Region, Russia aut Zavalov Y. Institute on Laser and Information Technology of Russian Academy of Science, 1 Svyatoozerskaya st., 140700, Shatura, Moscow Region, Russia aut Panchenko V. Institute on Laser and Information Technology of Russian Academy of Science, 1 Svyatoozerskaya st., 140700, Shatura, Moscow Region, Russia aut Applied Physics B Springer-Verlag 105/3(2011-11-01), 537-543 0946-2171 105:3<537 2011 105 340 https://doi.org/10.1007/s00340-011-4611-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00340-011-4611-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Dubrov A. Institute on Laser and Information Technology of Russian Academy of Science, 1 Svyatoozerskaya st., 140700, Shatura, Moscow Region, Russia aut NATIONALLICENCE 700 1- Dubrov V. Institute on Laser and Information Technology of Russian Academy of Science, 1 Svyatoozerskaya st., 140700, Shatura, Moscow Region, Russia aut NATIONALLICENCE 700 1- Zavalov Y. Institute on Laser and Information Technology of Russian Academy of Science, 1 Svyatoozerskaya st., 140700, Shatura, Moscow Region, Russia aut NATIONALLICENCE 700 1- Panchenko V. Institute on Laser and Information Technology of Russian Academy of Science, 1 Svyatoozerskaya st., 140700, Shatura, Moscow Region, Russia aut NATIONALLICENCE 773 0- Applied Physics B Springer-Verlag 105/3(2011-11-01), 537-543 0946-2171 105:3<537 2011 105 340 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer