Preparation and Numerical Simulation Investigation of High Reflectance Anti-laser-ablation Coating

doi:10.15541/jim20150633

Abstract

Abstract:

An anti-laser-ablation coating using TiO₂as pigment and potassium silicate as binder (abbreviated as KS-T) was deposited on the aluminum alloy substrate by an air spray process. Factors influencing the reflectance of KS-T coating, including particle size, pigment volume concentration and coating thickness, were investigated. The reflectance of prepared KS-T coating could be up to 96.8% at the laser wavelength of 1064 nm. A three-dimensional finite element model based on the heat-conduction equation was developed to simulate the distribution of transient temperature filed. By monitoring the temperature variation at the backside center of aluminum alloy substrate during laser irradiation and comparing with the simulation results, it is found that KS-T coating could effectively protect the substrate from laser ablation. The simulation results demonstrated reflectance decrease of samples after a period of irradiation. The possible reasons for the reflectance decrease were proposed. The calculation results also showed that an obvious temperature drop emerged at the coating/substrate interface when interface thermal resistance (ITR) was considered. Eventually heat flux was prevented from flowing to the substrate and aluminum alloy kept a low temperature.

Key words: anti-laser-ablation coating, high reflectance, finite element modeling, interface thermal resistance (ITR)

CLC Number:

TQ174

ZOU Yang, ZHAO Li-Li, YOU Li-Jun, CHEN Xiao-Ying, SONG Li-Xin. Preparation and Numerical Simulation Investigation of High Reflectance Anti-laser-ablation Coating[J]. Journal of Inorganic Materials, 2016, 31(8): 869-875.

Figures/Tables 9

Fig. 1 The three-dimensional finite simulation model

Fig. 2 Reflectance spectra of KS-T coating with different TiO2 particle sizes

Fig. 3 The 1064-nm reflectance of KS-T coating influenced by pigment volume concentration

Fig. 4 Images of samples irradiated by 1064-nm CW laserUncoated sample (laser switched off at 11 s); (b) Coated 200 µm KS-T coating (laser switched off at 36 s)

Table 1 Temperature-dependent parameters of KS-T coating

T / ℃	25	100	200	300	400	500	600	700
k/(W·m^-1·K^-1)	1.145	0.943	0.883	0.805	0.790	0.746	0.727	0.727
C_p/(J·kg^-1·K^-1)	699	772	844	881	907	937	967	978

Fig. 5 Typical temperature at backside center of the aluminum alloy vs time

Fig. 6 Comparison of the experimental and simulation results(a) Without considering reflectance change; (b) Considering reflectance change

Fig. 7 The simulation results(a) Backside center temperature of the sample coated by KS-T coating; (b) Temperature along the path B; (c) Temperature distribution plot without considering interface thermal resistance; (d) Temperature distribution plot with considering interface thermal resistance. ((b)-(d) are at the ending time of laser irradiation)

Fig. 8 SEM images of surfaces of KS-T coating(a) Before laser irradiation; (b) After laser irradiation

References 27

[1]	LI X F, WINFIELD R J, O’BRIEN S, et al. Application of Bessel beams to 2D microfabrication.Applied Surface Science, 2009, 255(10): 5146-5149.
[2]	SROKA R, STEPP H, HENNIG G, et al.Medical laser application: translation into the clinics.Journal of Biomedical Optics, 2015, 20(6): 061110.
[3]	ESKELINEN J, HÆGGSTRÖM E, DELIKARIS-MANIAS S, et al. Beamforming with a volumetric array of massless laser spark sources—Application in reflection tracking. The Journal of the Acoustical Society of America, 2015, 137(6): EL389-EL395.
[4]	ANDRE B, POUPINET L, RAVEL G.Evaporation and ion assisted deposition of HfO2 coatings: some key points for high power laser applications.Journal of Vacuum Science & Technology A, 2000, 18(5): 2372-2377.
[5]	WANG W, LUO Y, ZHANG D, et al.Dynamic optical limiting experiments on vanadium dioxide and vanadium pentoxide thin films irradiated by a laser beam.Applied Optics, 2006, 45(14): 3378-3381.
[6]	YUAN L, ZHAO Y, SHANG G, et al.Comparison of femtosecond and nanosecond laser-induced damage in HfO2 single-layer film and HfO2-SiO2 high reflector.JOSA B, 2007, 24(3): 538-543.
[7]	CHEN X, SONG L, YOU L, et al.Incorporation effect of Y2O3 on the structure and optical properties of HfO2 thin films.Applied Surface Science, 2013, 271: 248-252.
[8]	LIU N, WANG Y J, ZHOU M, et al.Laser resistance of Ta2O5/SiO2 and ZrO2/SiO2 optical coatings under 2 µm femtosecond pulsed irradiation.Chinese Physics Letters, 2010, 27(7): 074215.
[9]	SHEN J, ZHANG Q, WANG J, et al.Sol-Gel processing of zirconia coating for HR mirrors with high laser damage threshold.Journal of Sol-Gel Science and Technology, 2000, 19(1/2/3): 271-274.
[10]	STOLZ C J, GÉNIN F Y. Laser Resistant Coatings. Springer Berlin Heidelberg, 2003: 309-333.
[11]	KUMAR S, VERMA N K, SINGLA M L.Study on reflectivity and photostability of Al-doped TiO2 nanoparticles and their reflectors.Journal of Materials Research, 2013, 28(03): 521-528.
[12]	ZHANG L, YAN C W, QU Q, et al.Study on the protection of TiO2-K2SiO3 inorganic coatings for Ag used in space.Acta Chimica Sinica-Chinese Edition, 2003, 61(9): 1369-1374.
[13]	KUMAR S, VERMA N K, SINGLA M L.Size dependent reflective properties of TiO2 nanoparticles and reflectors made thereof.Digest Journal of Nanomaterials and Biostructures, 2012, 7(2): 607-619.
[14]	MIKHAILOV M M, SOKOLOVSKII A N.Photostability of coatings based on TiO2 (rutile) doped with potassium peroxoborate.Journal of Spacecraft and Rockets, 2006, 43(2): 451-455.
[15]	FAROOQ W A, ATIF M, ALI S M, et al.Effects of 1064 nm laser on the structural and optical properties of nanostructured TiO2 thin film.Optics and Spectroscopy, 2014, 117(3): 386-391.
[16]	OLIVEIRA V, VILAR R.Finite element simulation of pulsed laser ablation of titanium carbide.Applied Surface Science, 2007, 253(19): 7810-7814.
[17]	WANG L, ZHONG X H, ZHAO Y X, et al.Effect of interface on the thermal conductivity of thermal barrier coatings: a numerical simulation study.International Journal of Heat and Mass Transfer, 2014, 79: 954-967.
[18]	MADENCI E, GUVEN I.The Finite Element Method and Applications in Engineering Using ANSYS®. Springer, 2015.
[19]	PAEK U C, KESTENBAUM A.Thermal analysis of thin-film micromachining with lasers.Journal of Applied Physics, 1973, 44(5): 2260-2268.
[20]	MARIMUTHU S, MHICH A, MOLCHAN I S, et al.Numerical simulation of excimer laser cleaning of film and particle contaminants.Journal of Heat Transfer, 2013, 135(12): 121301.
[21]	SWARTZ E T, POHL R O.Thermal resistance at interfaces.Applied Physics Letters, 1987, 51(26): 2200-2202.
[22]	JENG Y R, CHEN J T, CHENG C Y.Thermal contact conductance of coated surfaces.Wear, 2006, 260(1): 159-167.
[23]	BRADY R F, WAKE L V.Principles and formulations for organic coatings with tailored infrared properties.Progress in Organic Coatings, 1992, 20(1): 1-25.
[24]	UJIHARA K.Reflectivity of metals at high temperatures.Journal of Applied Physics, 1972, 43(5): 2376-2383.
[25]	WOODCRAFT A L.Predicting the thermal conductivity of aluminium alloys in the cryogenic to room temperature range.Cryogenics, 2005, 45(6): 421-431.
[26]	HO K C, LIN J, DEAN T A.Modelling of springback in creep forming thick aluminum sheets.International Journal of Plasticity, 2004, 20(4): 733-751.
[27]	PAN X, YANG M Q, FU X, et al.Defective TiO2 with oxygen vacancies: synthesis, properties and photocatalytic applications.Nanoscale, 2013, 5(9): 3601-3614.