Journal of the Korean institute of surface engineering (한국표면공학회지)

The Korean Institute of Surface Engineering (한국표면공학회)
권호 표지
DOI QR코드

DOI QR Code

Process Parameter Selection for Plasma Electrolytic Oxidation to Improve Heat Dissipation Performance of Aluminum Alloy Heat Sink for Shipboard LED Luminaries

선박용 LED 등기구의 알루미늄 합금 방열판의 방열성능 향상을 위한 플라즈마 전해 산화의 공정변수 선정에 관한 연구

  • Lee, Jung-Hyung (Division of Marine Engineering, Mokpo National Maritime University) ;
  • Jeong, In-Kyo (Global Seafarers Training Center, G-Marine Service Co, Ltd.) ;
  • Han, Min-Su (Division of Marine Engineering, Mokpo National Maritime University)
  • 이정형 (목포해양대학교 기관시스템공학부) ;
  • 정인교 (지마린서비스) ;
  • 한민수 (목포해양대학교 기관시스템공학부)
  • Received : 2018.12.07
  • Accepted : 2018.12.17
  • Published : 2018.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

The possibility of an improvement in heat dissipation performance of aluminum alloy heat sink for shipboard LED luminaries through plasma electrolytic oxidation (PEO) was investigated. Four different PEO coatings were produced on aluminum alloy 5052 in silicate based alkaline solution by varying current density ($50{\sim}200mA/cm^2$). On voltage-time response curves, three stages were clearly distinguished at all current densities, namely an initial linear increase, slowdown of increase rate, and steady state(constant voltage). It was found that the increase in current density caused the breakdown voltage to increase. Two different surface morphologies - coralline porous structure and pancake structure - were confirmed by SEM examination. The coralline porous structure was predominant in the coatings produced at lower current densities (50 and $100mA/cm^2$) while under high current densities(150 and $200mA/cm^2$) the pancake structure became dominant. The coating thickness was measured and found to be in a range between about $13{\mu}m$ and $44{\mu}m$, showing increasing thickness with increasing current density. As a result, $100mA/cm^2$ was proposed as an effective process parameter to improve the heat dissipation performance of aluminum alloy heat sink, which could lower the LED operating temperature by about 30%.

Keywords

PMGHBJ_2018_v51n6_415_f0001.png 이미지

Fig. 1. Picture of the specimen before and after PEO treatment.

PMGHBJ_2018_v51n6_415_f0002.png 이미지

Fig. 2. Schematic configuration of heat dissipation performance measurement system for aluminum alloy LED heat sink.

PMGHBJ_2018_v51n6_415_f0003.png 이미지

Fig. 4. SEM images of surface morphologies of PEO coatings produced with different current densities.

PMGHBJ_2018_v51n6_415_f0004.png 이미지

Fig. 3. Voltage-time response during PEO process for aluminum alloys treated under different current densities.

PMGHBJ_2018_v51n6_415_f0005.png 이미지

Fig. 5. Comparison of thickness of PEO coatings with different current densities.

PMGHBJ_2018_v51n6_415_f0006.png 이미지

Fig. 6. Result of EDS analysis for the PEO coating produced with 100 mA/cm2 of current density.

PMGHBJ_2018_v51n6_415_f0007.png 이미지

Fig. 7. Variation of LED temperatures for LEDs with different heat sinks.

PMGHBJ_2018_v51n6_415_f0008.png 이미지

Fig. 8. Infrared thermographic images of LED chip with aluminum alloy heat sink and surface-treated heat sink.

References

  1. S. J. Park, S. H. Byeon, S. J. Kim, K. S. Park, G. S. Kil, Economic analysis on the applications of shipboard LED luminaires, J. Korean Soc. Mar. Eng., 40 (2016) 342-347. https://doi.org/10.5916/jkosme.2016.40.4.342
  2. D. Jang, S. J. Yook, K. S. Lee, Optimum design of a radial heat sink with a fin-height profile for high-power LED lighting applications, Appl. Energy, 116 (2014) 260-268. https://doi.org/10.1016/j.apenergy.2013.11.063
  3. X. Y. Lu, T. C. Hua, M. J. Liu, Y. X. Cheng, Thermal analysis of loop heat pipe used for high-power LED, Thermochim. Acta, 493 (2009) 25-29. https://doi.org/10.1016/j.tca.2009.03.016
  4. Y. J. Heo, H. T. Kim, K. J. Kim, S. Nahm, Y. J. Yoon, J. Kim, Enhanced heat transfer by room temperature deposition of AlN film on aluminum for a light emitting diode package, Appl. Therm. Eng., 50(2013) 799-804. https://doi.org/10.1016/j.applthermaleng.2012.07.024
  5. D. Kim, J. Lee, J. Kim, C. H. Choi, W. Chung, Enhancement of heat dissipation of LED module with cupric-oxide composite coating on aluminumalloy heat sink, Energy Convers. Manag., 106 (2015) 958-963. https://doi.org/10.1016/j.enconman.2015.10.049
  6. M. Zhou, T. Lin, F. Huang, Y. Zhong, Z. Wang, Y. Tang, J. Lin, Highly conductive porous graphene/ceramic composites for heat transfer and thermal energy storage, Adv. Funct. Mater., 23 (2013) 2263-2269. https://doi.org/10.1002/adfm.201202638
  7. A. L. Yerokhin, X. Nie, A. Leyland, A. Matthews, S. J. Dowey, Plasma electrolysis for surface engineering, Surf. Coatings Technol., 122 (1999) 73-93. https://doi.org/10.1016/S0257-8972(99)00441-7
  8. J. H. Lee, C. R. Son, S. J. Kim, Influence of $Na_2SiO_3$ addition on surface microstructure and cavitation damage characteristics for plasma electrolytic oxidation of Al-Mg alloy, Jpn. J. Appl. Phys., 55(1S) (2016) 01AF02-01-01AF02-05.
  9. W. C. Gu, G. H. Lv, H. Chen, G. L. Chen, W. R. Feng, S. Z. Yang, Characterisation of ceramic coatings produced by plasma electrolytic oxidation of aluminum alloy, Mater. Sci. Eng., A 447 (2007) 158-162. https://doi.org/10.1016/j.msea.2006.09.004
  10. A. L. Yerokhin, L. O. Snizhko, N. L. Gurevina, A. Leyland, A. Pilkington, A. Matthews, Spatial characteristics of discharge phenomena in plasma electrolytic oxidation of aluminium alloy, Surf. Coatings Technol., 177 (2004) 779-783.
  11. J. A. Curran, T. W. Clyne, Porosity in plasma electrolytic oxide coatings, Acta Mater., 54 (2006) 1985-1993. https://doi.org/10.1016/j.actamat.2005.12.029
  12. R. H. U. Khan, A. X. Yerokhin, H. Dong, A. Matthews, Surface characterisation of DC plasma electrolytic oxidation treated 6082 aluminium alloy: Effect of current density and electrolyte concentration, Surf. Coatings Technol., 205 (2010) 1679-1688. https://doi.org/10.1016/j.surfcoat.2010.04.052
  13. R. O. Hussein, X. Nie, D. O. Northwood, A. Yerokhin, A. Matthews, Spectroscopic study of electrolytic plasma and discharging behaviour during the plasma electrolytic oxidation (PEO) process, J. Phys. D. Appl. Phys., 43 (2010) 105203. https://doi.org/10.1088/0022-3727/43/10/105203
  14. O. Rozenbaum, D. D. S. Meneses, P. Echegut, Texture and porosity effects on the thermal radiative behavior of alumina ceramics, Int. J. Thermophys., 30 (2009) 580-590. https://doi.org/10.1007/s10765-008-0510-1
  15. X. He, Y. Li, L. Wang, Y. Sun, S. Zhang, High emissivity coatings for high temperature application: progress and prospect, Thin Solid Films, 517 (2009) 5120-5129. https://doi.org/10.1016/j.tsf.2009.03.175
  16. Y. M. Wang, H. Tian, X. E. Shen, L. Wen, J. H. Ouyang, Y. Zhou, L. X. Guo, An elevated temperature infrared emissivity ceramic coating formed on 2024 aluminium alloy by microarc oxidation, Ceram. Int., 39(2013) 2869-2875. https://doi.org/10.1016/j.ceramint.2012.09.060