Microstructure and Corrosion Behavior of Ni-AlloyCrN Nanolayered Coatings

الملخص EN

The Ni-alloy/CrN nanolayered coatings, Ni-Al/CrN and Ni-P/CrN, were deposited on (100) silicon wafer and AISI 420 stainless steel substrates by dual-gun sputtering technique.

The influences of the layer microstructure on corrosion behavior of the nanolayered thin films were investigated.

The bilayer thickness was controlled approximately 10 nm with a total coating thickness of 1 μm.

The single-layer Ni-alloy and CrN coatings deposited at 350∘C were also evaluated for comparison.

Through phase identification, phases of Ni-P and Ni-Al compounds were observed in the single Ni-alloy layers.

On the other hand, the nanolayered Ni-P/CrN and Ni-Al/CrN coatings showed an amorphous/nanocrystalline microstructure.

The precipitation of Ni-Al and Ni-P intermetallic compounds was suppressed by the nanolayered configuration of Ni-alloy/CrN coatings.

Through Tafel analysis, the Ecorr and Icorr values ranged from –0.64 to –0.33 V and 1.42×10−5 to 1.14×10−6 A/cm2, respectively, were deduced for various coating assemblies.

The corrosion mechanisms and related behaviors of the coatings were compared.

The coatings with a nanolayered Ni-alloy/CrN configuration exhibited a superior corrosion resistance to single-layer alloy or nitride coatings.