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Abstract
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Two layers of AlNeTiN coating were deposited onto SS316L as PEM bipolar plate using
plasma focus device for 5, 10 and 20 shots number. The XRD patterns of all coated samples
reveal formation of TiN, Ti2N and AlTi3N crystallite phases on the surface. Using the
Scherrer formula the crystallite size of the coating layer is estimated about 20e40 nm.
Thickness of the two layers coating obtained from cross sectional SEM of the samples is in
the range of 5e15 mm. Through the potentiostatic test considerable decrease of the current
density of the 20 shots coated samples is achieved. The ICR of the samples reduced as
follows: 20 shots < 10 shots < 5 shots < bare sample which confirms that the electrical
conductivity of the bipolar plate is increased due to the formation of AlN and TiN coating.
SEM morphology of all samples before and after potentiostatic tests shows that the coated
samples are exposed to less corrosion compare with the bare sample. These results are in
good agreement with electrochemical tests and the 20 shots sample has the lowest
corrosion.
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