What is the difference between anodization and micro arc oxidation?
very similar techniques. However micro arc oxidation is done at a higher applied potential (than anodization) and discharges/plasma are therefore generated. this influences the anodic structure you are growing. (i.e. for example you can generate crystalline films). because of the higher potential you can grow thicker film in a shorter time using micro arc oxidation.
very similar techniques. However micro arc oxidation is done at a higher applied potential (than anodization) and discharges/plasma are therefore generated. this influences the anodic structure you are growing. (i.e. for example you can generate crystalline films). because of the higher potential you can grow thicker film in a shorter time using micro arc oxidation.
Dear Dr.Domenico Regonini,
thank you very much for your valuable answer. i dont know why discharges/plasma are generated at a higher applied potential....can you help me?
if you use a sufficiently high potential, you may generate an electric field higher than a critical value for the given anodic film you are growing during the process. In other words you are working above the so called breakdown potential (maximum potential/field that can be sustained by a certain material before charging/breakdown occurs) and as a consequence you generate sparks and discharges within the film. This will also affect the local temperature of the film and the electrolyte, hence you may have crystallization processes which would not occur under milder anodizing conditions. There are plenty of books and articles that you can read to gain an understanding on both processes. I would suggest you to look for a good review on the subject as there you will find the answer to most of the questions you have
Dear Dr.Domenico Regonini,
Thank you very much for your suggestions.
Dear Dr.Domenico Regonini,
suppose if i am taking Ti as anode (water as electrolyte) in annodization process (you told there is no crystallization process) whether i will get oxygen atoms bed on the titanium surface or the both the atoms are exposed on coating surface?
crystallization depends on so many things (potential, electrolyte, etc.) that only way to know is to characterize your samples. I just gave you an example that with micro arc oxidation you are more likely to have better crystallinity. Generally with anodization you may have an amorphous layer of TiO2 (although you may also have some crystalline regions) and for sure you are going to have both Ti and O atoms exposed at the surface of the film. you will likely have some hydrated form of TiO2 too in your anodic film. hope this helps. best way is to play around with your rig, then with XRD or Raman, TEM you can find out if you have crystal or amorphous structure
Please, can I use AC current not DC. if yes, do you think just only the high voltage is required for controlling such as film thickness. I need help please. I saw many papers are using pulsed power supply
Hi dear Abdalla, the AC current is used for this kind of coatings, but i think you may have frequency range and power problem and the coating surface is uneven and very rough, if you have not pulsed current why you do not using DC current?
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