PSI - Issue 40

S.A. Filin et al. / Procedia Structural Integrity 40 (2022) 153–161 S. A. Filin at al. / Structural Integrity Procedia 00 (2022) 000 – 000

157

5



/ 1 1 E R 

C  

e

  

0

1         0 1 T T C

0

(11)

,

where E - is the activation energy; τ 0 - time complete dissolution for some fixed values of T 0 and C 0 . The time of complete dissolution can be calculated at other values, for example, T 1 and C 1 (Golubchikov et al. (2013)). The cleaning speed is influenced by: 1) physicochemical properties: a) contaminations (chemical composition, strength and rheological properties), b) the surface to be cleaned (material, roughness, size, configuration, etc.), c) the detergent medium (composition , concentration, temperature - are the main factors, that determine the affinity of the detergent medium for contamination (work of Aadmc)); 2) the amount of contaminations before and after cleaning, the requirements for the uniform distribution of residual contamination over the surface; 3) the nature and parameters of the interaction of the detergent medium with the surface (speed and dimensional parameters of the flow (the main factors, determining the work (Amidm), associated with the mechanical action of the detergent medium). An increase in the temperature of the solvent during metal cleaning significantly increases the efficiency of the detergent medium. However, this can lead to the destruction of the solvent and the acceleration of metal corrosion. In addition, with an increase in temperature, the critical concentration of micelle formation increases, which leads to a decrease in the stabilization of the contaminants, which are detergent. A significant disadvantage of using emulsifiers, when cleaning laser metal optics, is the wedging effect, which can lead to a deterioration in the optical parameters during the cleaning process (an increase in the damaged layer, an increase in the size and number of microcracks). The nature and parameters of the interaction of the cleaning medium with the surface depend on the methods of intensification of cleaning (Aripdjanov and Tirkasheva (2021); Marchenko et al. (2015); Cogliastro et al. (2001); Juvonen et al. (2000); Casares and Kodriguez (1989); Eremeev et al. (2003)). The nature and parameters of the interaction of the detergent medium with the surface depend on the methods of intensification of cleaning (Rylov et al. (2000); Zheng et al. (2015); Likhachev et al. (2014); Kulagin et al. (2008)). They define work (Amidm) of intensification of cleaning, under which the object is immersed in the detergent medium, consists in: 1) activation of the detergent medium by flooded jets (screws, pumps, compressed air are used); 2) vibration activation of the detergent medium (ultrasonic processes, vibration abrasive treatment); in moving an object in the detergent medium (oscillatory or rotational movement of objects); in passing an electric current in the detergent medium (electrochemical processes, electrohydraulic effect) (Kulagin et al. (2008); Kulagin and Pyanykh (2014); Mahmood Fashandi et al. (2017); Abbasi et al. (2016); Ghasemi et al. (2014); Baümler et al. (2016); Timofeeva et al. (2008)). The disadvantage of intensification of cleaning by means of vibration activation of the detergent medium is that a significant growth of the damaged layer on the optical surface can occur, in particular, due to the abrasive particles embedded in it, which, in turn, will cause deterioration of the optical parameters. Passing current can ignite the detergent medium and destroy the mirror. Intensification of cleaning, in which the detergent medium is supplied to the surface, can be carried out by cleaning with jets (hydraulic, hydro abrasive, dry cleaning media) and cleaning with physicochemical active detergent media. Of the above methods, it is advisable to use jet cleaning for mirrors. Other methods either lead to a deterioration in optical properties (due to corrosion under the action of hydraulic jets and an increase in the damaged layer during mechanical processing of metal products using metal brushes), or are not sufficiently effective. During jet cleaning, the solvent is supplied at a pressure of 0.03-0.1 MPa, while the dissolving effect of the jet is complemented by its impact. This method is especially effective in removing insoluble or poorly soluble contaminants such as abrasive particles. The disadvantage of blast cleaning is the difficulty of cleaning elements of complex configuration, high consumption and, often, irrecoverable losses of the cleaning medium. When cleaning objects in the vapor phase, solvent vapors condense onto the cold surface of the mirror and dissolve the impurities. Solvent vapors condense on the mirror until its temperature reaches the vapor temperature. The main advantage of vapor phase cleaning is that condensing vapors do not contain dissolved contaminations.