| Title |
Effect of Na2WO4 in electrolyte on mechanical properties of oxide layer on Al alloy via plasma electrolytic oxidation |
| Authors |
양해웅(Hae Woong Yang); 김연성(Yeon Sung Kim); 박주현(Joo Hyun Park); 김계원(Gye Won Kim); 고영건(Young Gun Ko); 신동혁(Dong Hyuk Shin) |
| DOI |
https://doi.org/10.3365/KJMM.2015.53.8.535 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Al alloy; coating; plasma electrolytic oxidation; mechanical properties; scanning electron microscopy; SEM |
| 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) |