Investigation of wear and corrosion resistance of nanocomposite coating formed on AZ31B Mg alloy by plasma electrolytic oxidation

2017 ◽  
Vol 95 (6) ◽  
pp. 308-315 ◽  
Author(s):  
H. Nasiri Vatan ◽  
M. Adabi
Keyword(s):  
Corrosion Resistance ◽  
Plasma Electrolytic Oxidation ◽  
Nanocomposite Coating ◽  
Mg Alloy ◽  
Wear And Corrosion ◽  
Electrolytic Oxidation ◽  
Wear And Corrosion Resistance ◽  
Plasma Electrolytic

Simultaneous Reduction of Wear and Corrosion of Titanium, Magnesium and Zirconium Alloys by Surface Plasma Electrolytic Oxidation Treatment

2008 ◽  
Vol 38 ◽  
pp. 27-35 ◽  
Author(s):  
H.M. Nykyforchyn ◽  
V.S. Agarwala ◽  
M.D. Klapkiv ◽  
V.M. Posuvailo
Keyword(s):  
Corrosion Resistance ◽  
Plasma Electrolytic Oxidation ◽  
Synthesis Method ◽  
Zirconium Alloys ◽  
Ceramic Coatings ◽  
Oxide Ceramic ◽  
Wear And Corrosion ◽  
Electrolytic Oxidation ◽  
Wear And Corrosion Resistance ◽  
Plasma Electrolytic

Titanium, magnesium and zirconium alloys are widely used in industrial applications, which require high wear and corrosion resistance. However current methods of improving these properties often do not satisfy the requirements of service and functional properties. An alternative approach is the application of oxide-ceramic coatings using high temperature process. The coatings are applied by spark discharge plasma in the metal-electrolyte system at high voltages - PEO (plasma electrolytic oxidation) as an oxide synthesis method. This method has shown good results for aluminium alloys and with good prospects to be used for titanium, magnesium and zirconium alloys. Development of PEO technology to improve the wear and corrosion resistance of titanium, magnesium and zirconium alloys is discussed in this paper. It describes the methods for obtaining the required layer-thickness for a specified hardness, porosity, wear and corrosion resistance, sets up the optimal process parameters (voltage/current) by taking the relation of anodic to cathodic currents into account, and establishing the electrolyte content of different dopants.

scholarly journals The effect of process current parameters on the properties of oxide layers under plasma electrolytic oxidation of AMg6 alloy

2021 ◽  
Vol 2144 (1) ◽  
pp. 012018
Author(s):  
A V Polunin ◽  
A G Denisova ◽  
A O Cheretaeva ◽  
M R Shafeev ◽  
E D Borgardt ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Plasma Electrolytic Oxidation ◽  
Oxide Layers ◽  
Positive Pulse ◽  
Pulse Ratio ◽  
Wear And Corrosion ◽  
Electrolytic Oxidation ◽  
Wear And Corrosion Resistance ◽  
Plasma Electrolytic

Abstract The effect of current density and current ratio in the cathodic and anodic half-cycles during prolonged (180 minutes) plasma electrolytic oxidation (PEO) of AMg6 wrought alloy on the oxide layer wear and corrosion resistance were studied. It was established that the best wear resistance is achieved in the oxide layers obtained in the “soft sparking” mode (negative-to-positive pulse ratios of 1.15–1.30) at current densities of 9–15 A dm−2, and the best set of wear resistance and corrosion resistance – in the oxide layers obtained in “symmetrical” mode (negative-to-positive pulse ratio of 1.00).

scholarly journals Improving Corrosion Resistance of MRI 230D Mg Alloy by Hybrid Coating of Laser Surface Alloying and Plasma Electrolytic Oxidation

2012 ◽  
Vol 706-709 ◽  
pp. 1209-1214 ◽  
Author(s):  
G. Rapheal ◽  
Subodh Kumar ◽  
Carsten Blawert ◽  
Narendra B. Dahotre
Keyword(s):  
Corrosion Resistance ◽  
Plasma Electrolytic Oxidation ◽  
Laser Surface ◽  
Mg Alloy ◽  
Hybrid Coatings ◽  
Corrosion Tests ◽  
Micro Cracks ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
Scanning Electron

A permanent mould cast creep resistant MRI 230D Mg alloy was laser surface alloyed (LSA) with Al and Al2O3 in order to improve its wear and corrosion resistance. However, this treatment was successful only in improving wear resistance but not corrosion resistance due to the presence of micro−cracks in the coated layer, which has been discussed in an earlier paper. The LSA coated Mg alloy has been further subjected to plasma electrolytic oxidation (PEO) treatment in alkaline silicate electrolyte in order to cover those micro−cracks and improve corrosion resistance, which is discussed in the present manuscript. For comparison, the PEO coating has also been applied on the as−cast MRI 230D Mg alloy. The microstructural characterization of coatings and corroded surfaces was carried out by scanning electron microscope and X−ray diffraction. Electrochemical corrosion tests were conducted in 3.5 wt% NaCl solution having neutral pH to investigate the corrosion behavior. The LSA coatings consisted mainly of β (Mg17Al12) phase, the coatings produced by PEO treatment on MRI 230D Mg alloy consisted mainly of Mg2SiO4 phase, and hybrid coatings of PEO on LSA consisted of Mg2SiO4 and MgAl2O4 phases in the PEO layer. Scanning electron micrographs of the cross−section revealed that the PEO treatment covered the micro−cracks present in the LSA and corrosion tests revealed that it improved the corrosion resistance, though not to the extent of the corrosion resistance of the PEO coated MRI 230D Mg alloy. All the samples exhibited localized form of corrosion.

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