PSI - Issue 50

S.A. Filin et al. / Procedia Structural Integrity 50 (2023) 91–99 S. A. Filin at al. / Structural Integrity Procedia 00 (2022) 000 – 000

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The control of the chemical purity of the mirrors on the "EF-3MA" brand electronic fluorimeter and the "LPE 3M-1" brand laser photoelectric ellipsometer (on the witness samples) showed, that the amount of contaminants did not exceed 10 -9 mol/cm 2 . The mechanism of some increase in SRС after cleaning is probably because, when the mirror is exposed to laser radiation with a power density close to the optical damage, the effect of laser cleaning is observed (Hyvarinen et al. (2000); Khan et al. (2021); Bertasa and Korenberg (2022); Ding et al. (2021); Li et al. (2020); Li et al. (2020)). The burnout of absorbing impurities contributes to an increase in SRС after purific ation from combustion products. During the operation of the mirror inside the laser cell, in addition to this process, there is a competing process of deposition on the mirror of decomposition products of a chemically active medium, which overlaps the effect of laser cleaning and causes degrading of SRС. The complete removal of the absorbing film from the mirror surface because of the physicochemical cleaning process exhibits the effect of laser cleaning of the near-surface optical layer and, consequently, leads to an increase in SRС. 6. Conclusion 1. The main ways to stabilize the properties of halogenated hydrocarbons are their operation at the lowest possible temperatures (taking into account, of course, the possible decrease herewith in dissolving power), as well as their use in the form of azeotropes, that provide a lower boiling point of the azeotrope compared to a pure solvent. 2. The expediency of using a washing mixture based on "freon-114B2 - acetone - tert-butanol" for cleaning metal optics is shown as the most effective cleaning medium. An estimate of the optical damage of the surface after treatment with this washing mixture showed maximum close to the calculated one. 3. The selection of azeotropes with the solubility parameter and polar selectivity of the components, coinciding or close to similar parameters of technological pollution, made it possible to carry out the most effective cleaning of optics. 4. The practical implementation of the possibility and legitimacy of choosing washing mixtures for cleaning optics, using the solubility parameter δ for azeotropes of solvents made it possible to apply the proposed method for stabilizing halogenated hydrocarbons. 5. Technically and technologically are implemented: a) the process of physical and chemical purification of metals in a closed technological cycle, and b) a method of multiple recovery of metal optics, which works under high-energy exposure in a gas discharge environment, without the use of mechanical restoration (grooving, grinding and polishing). At the same time, the specular reflection coefficient exceeded the value measured before the start of operation. References Qin, J.J., Oo, M.H., Wong, F.S., 2006. Pilot study on the treatment of spent solvent cleaning rinse in metal plating, Desalination 191(1-3), 359 364. http://doi.org/10.1016/j.desal.2005.05.027 Martin, A.R., Baeyens, M., Hub, W., Mertens, P.W., Kolbesen, B.O., 1999. Alkaline cleaning of silicon wafers: additives for the prevention of metal contamination. Microelectronic Engineering 45(2-3), 197-208. http://doi.org/10.1016/S0167-9317 (99)00150-1 Quaas, A.C., Heide, S., Freitag, S., Kern, M., 2005. Influence of metal cleaning methods on the resin bond strength to nicr alloy. Dental Materials 21(3), 192-200. http://doi.org/10.1016/j.dental.2004.04.001 Muñoz , J., Bravo, J.A., Calzada, M.D., 2017. Aluminum metal surface cleaning and activation by atmospheric-pressure remote plasma. Applied Surface Science 407, 72-81. http://doi.org/10.1016/J.APSUSC.2017.02.092 Aslan, A., Salur, E., Güneş , A., Şahin , Ö.S., Karadağ , H.B., Akdemir, A., 2021. The effect of ultrasonic cleaning upon mechanical properties of metal matrix composites. Transactions of the Indian Institute of Metals 74(1), 107-118. http://doi.org/10.1007/s12666-020-02104-6 Kaplunov, I.A., Rogalin, V.E., Filin, S.A., 2015. Analysis of laser-chemical cleaning of metal surfaces. Non-ferrous Metals 1, 29 – 31. http://doi.org/10.17580/nfm.2015.01.07 Drobot, A.D., Ilyin, M.K., Rogalin, V.E., Filin, S.A., Yampolsky, V.I., Narusbek, E.A., 1995. Method of cleaning the optical surface of metal products and their alloys. RUS Patent No 2049155. Drobot, A.D., Ilyin, M.K., Rogalin, V.E., Filin, S.A., Yampolsky, V.I., 1996. Method of cleaning the surface of products made of metals and their alloys. RUS Patent No 2070621. Akasaka, R. Higashi, Y. Yamada, Y. Shibanuma, T., 2015. Thermodynamic properties of 1,1,1,2-tetrafluoroethane (R-134a) + 2,3,3,3 tetrafluoropropene (R-1234yf) mixtures: Measurements of the critical parameters and a mixture model based on the multi-fluid approximation. International J. Refrigeration 58, 146 – 153. http://doi.org/10.1016/j.ijrefrig.2015.06.011