Počet záznamů: 1
Use of schlieren methods to study gas flow in laser technology
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SYSNO ASEP 0465803 Druh ASEP C - Konferenční příspěvek (mezinárodní konf.) Zařazení RIV D - Článek ve sborníku Název Use of schlieren methods to study gas flow in laser technology Tvůrce(i) Mrňa, Libor (UPT-D) RID, ORCID, SAI
Pavelka, Jan (UPT-D) RID, SAI
Horník, Petr (UPT-D) RID, ORCID, SAI
Hrabovský, J. (CZ)Celkový počet autorů 4 Zdroj.dok. Optics and Measurement International Conference 2016 (Proceedings of SPIE 10151). - Bellingham : SPIE, 2016 - ISSN 0277-786X Rozsah stran 101510i:1-7 Poč.str. 7 s. Forma vydání Tištěná - P Akce Optics and Measurement International Conference 2016 Datum konání 11.09.2016 - 14.09.2016 Místo konání Liberec Země CZ - Česká republika Typ akce WRD Jazyk dok. eng - angličtina Země vyd. US - Spojené státy americké Klíč. slova schlieren imaging ; laser welding ; laser cutting Vědní obor RIV BH - Optika, masery a lasery CEP ED0017/01/01 GA MŠMT - Ministerstvo školství, mládeže a tělovýchovy LO1212 GA MŠMT - Ministerstvo školství, mládeže a tělovýchovy TA04020456 GA TA ČR - Technologická agentura ČR Institucionální podpora UPT-D - RVO:68081731 UT WOS 000393154700018 EID SCOPUS 85012865283 DOI https://doi.org/10.1117/12.2257212 Anotace Laser technologies such as welding and cutting rely on process gases. We suggest to use schlieren imaging to visualize the gas flow during these processes. During the process of laser welding, the shielding gas flows to the welded area to prevent oxidation of the weld pool by surrounding air. The gas also interacts with hot plasma spurting from the key hole induced by the laser beam incident on the molten material. This interaction is quite complicated because hot plasma mixes with the cold shielding gas while the system is moving along the weld. Three shielding gases were used in the presented experiment: Ar, He and N2. Differences in dynamics of the flow are clearly visible on schlieren images. Moreover, high speed recording reveals a structure consisting of hot gas bubbles. We were also able to determine the velocity of the bubbles from the recording. During laser cutting, the process gas flows coaxially with the laser beam from the nozzle to remove the molten material out of the kerf. The gas flow is critical for the quality of the resulting edge of the cut. Schlieren method was used to study gas flow under the nozzle and then under the material being cut. This actually creates another slot nozzle. Due to the very low speed of flow below the material the schleiren method is already at the limit of its sensitivity. Therefore, it is necessary to apply a differential technique to increase the contrast. Distinctive widening of the flow shaped by the kerf was observed. Pracoviště Ústav přístrojové techniky Kontakt Martina Šillerová, sillerova@ISIBrno.Cz, Tel.: 541 514 178 Rok sběru 2017
Počet záznamů: 1