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Vol.53, No.8, 535 ~ 541, 2015
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| Title |
| Effect of Na2WO4 in electrolyte on mechanical properties of oxide layer on Al alloy via plasma electrolytic oxidation |
| 양해웅 Hae Woong Yang , 김연성 Yeon Sung Kim , 박주현 Joo Hyun Park , 김계원 Gye Won Kim , 고영건 Young Gun Ko , 신동혁 Dong Hyuk Shin |
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| Abstract |
| This paper investigates with the mechanical properties of Al alloy samples coated by plasma electrolytic oxidation (PEO) using a phosphate electrolyte with a Na2WO4 solution. Under an A Ccondition of 60Hz, PEO coatings were applied for 300 seconds at a current density of 100mA/cm2. Microstructural observations of the PEO-coated samples revealed that the size and fraction of the micro-pores remained nearly constant while WO3 and W were additionally in corporated in the oxide layer using the Na2WO4 solution. During PEO coating, the Na2WO4 solution dissociated into Na+ and WO4 2- and the high dielectric voltage exceeding the ignition voltage activated the electrochemical reactions of WO4 2- in the anode, leading to the formation of WO3 and W. The incorporation of WO3 and W is expected to lead to enhancement of the hardness and wear resistance of the PEO-coated Al sample. (Received October 08, 2014) |
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| Key Words |
| Al alloy, coating, plasma electrolytic oxidation, mechanical properties, scanning electron microscopy, SEM |
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