Nanoindentation and scratch behaviour of Ni–P electroless coatings

2019 ◽  
Vol 14 (1) ◽  
pp. 22-32 ◽  
Author(s):  
Renzo Valentini ◽  
Pasquale Cavaliere ◽  
Daniele Valerini
Keyword(s):  
Electroless Coatings

Comparison of corrosion resistance properties of Ni-P and Ni-W-P coatings obtained by electroless deposition

2020 ◽  
Vol 25 (2) ◽  
pp. 66-71
Author(s):  
A.B. Drovosekov
Keyword(s):  
Corrosion Resistance ◽  
Sulfuric Acid ◽  
Electroless Deposition ◽  
Corrosion Damage ◽  
Electrochemical Activity ◽  
High Porosity ◽  
Environment Analysis ◽  
Damage Degree ◽  
Lower Porosity ◽  
Electroless Coatings

Corrosion resistance properties, such as porosity, stability in the atmosphere of NaCl mist, and anodic electrochemical activity in a sulfuric acid solution are studied and compared for Ni-W-P and Ni-P coatings obtained by electroless deposition. The studied coatings were obtained from solutions with glycine as the main ligand and contained 10.2 to 15.6 at.% of phosphorus and up to 3.3 at.% of tungsten. It is shown that Ni-W-P coatings with a tungsten content of 2.3 to 3.3 at.% and a thickness of 15 μm have a significantly lower porosity as compared with nickel-phosphorus coatings of the same thickness. Also, significantly better stability of Ni-W-P coatings in a NaCl mist atmosphere was observed, their corrosion damage degree is less than that of Ni-P coatings, and relatively little depends on the duration of exposure in a corrosive environment. Analysis of anodic polarization curves showed an almost similar electrochemical activity upon dissolution of Ni-P and Ni-W-P coatings in sulfuric acid. Both these types of electroless coatings showed a markedly better tendency to anodic dissolution than pure nickel. Taking into account the obtained experimental data, a conclusion is made as to the better protective characteristics of Ni-W-P coatings in comparison with nickel-phosphorus coatings. The main reason of the inferior protective properties of Ni-P coatings is their relatively high porosity.

EFFECT OF HEAT TREATMENT ON MICROSTRUCTURE AND CORROSION RESISTANCE OF Ni-B-W-Mo COATING DEPOSITED BY ELECTROLESS METHOD

2018 ◽  
Vol 25 (08) ◽  
pp. 1950023 ◽  
Author(s):  
ARKADEB MUKHOPADHYAY ◽  
TAPAN KUMAR BARMAN ◽  
PRASANTA SAHOO
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Electrochemical Techniques ◽  
Sodium Molybdate ◽  
Medium Carbon Steel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid Solution Strengthening ◽  
Heat Treated ◽  
Electroless Coatings

The present work reports the deposition of a quaternary Ni-B-W-Mo coating on AISI 1040 medium carbon steel and its characterization. Quaternary deposits are obtained by suitably modifying existing electroless Ni-B bath. Composition of the as-deposited coating is analyzed by energy dispersive X-ray spectroscopy. The structural aspects of the as-deposited and coatings heat treated at 300[Formula: see text]C, 350[Formula: see text]C, 400[Formula: see text]C, 450[Formula: see text]C and 500[Formula: see text]C are determined using X-ray diffraction technique. Surface of the as-deposited and heat-treated coatings is examined using a scanning electron microscope. Very high W deposition could be observed when sodium molybdate is present in the borohydride-based bath along with sodium tungstate. The coatings in their as-deposited condition are amorphous while crystallization takes place on heat treatment. A nodulated surface morphology of the deposits is also observed. Vickers’ microhardness and crystallite size measurement reveal inclusion of W and Mo results in enhanced thermal stability of the coatings. Solid solution strengthening of the electroless coatings by W and Mo is also observed. The applicability of kinetic strength theory to the hardening of the coatings on heat treatment is also investigated. Corrosion resistance of Ni-B-W-Mo coatings and effect of heat treatment on the same are also determined by electrochemical techniques.

The Scraping Test and Adhesion Measurements of Diamond and Nickel Electroless Coatings

2000 ◽  
Vol 44 (4-5) ◽  
pp. 347-352 ◽  
Author(s):  
Zhongwei Xie ◽  
Jing Zhu ◽  
Wei Guo
Keyword(s):  
Electroless Coatings

The effect of Re addition on the thermal stability and structure of Ni–P electroless coatings

2021 ◽  
Vol 171 ◽  
pp. 110811
Author(s):  
Joanna Wojewoda-Budka ◽  
Anna Wierzbicka-Miernik ◽  
Maciej Szczerba ◽  
Honorata Kazimierczak ◽  
Izabella Kwiecien ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Electroless Coatings

AN INVESTIGATION ON EFFECTS OF TiO2 NANO-PARTICLES INCORPORATED IN ELECTROLESS NiP COATINGS' PROPERTIES

2012 ◽  
Vol 05 ◽  
pp. 833-840
Author(s):  
S.R. Allahkaram ◽  
S. Salmi ◽  
E. Tohidlou
Keyword(s):  
Corrosion Resistance ◽  
Composite Coatings ◽  
Amorphous Structure ◽  
Nano Particles ◽  
Acid Electrolyte ◽  
Sulfuric Acid Electrolyte ◽  
X65 Steel ◽  
Electroless Coatings ◽  
Api 5L X65 Steel ◽  
Steel Substrates

Electroless composite coatings have been vastly used in various industries during last decades due to their good properties, such as corrosion and wear resistance, hardness and uniform thickness. In this paper, co-deposition of TiO 2 nano-particles with Nickel-Phosphorus electroless coatings on API-5L-X65 steel substrates was investigated. Surface morphology and composition of coatings were studied via SEM and EDX, respectively. XRD analyses showed that these coatings had amorphous structure with TiO 2 crystalline particles. TiO 2 nano-particles increased microhardness of coatings. Corrosion resistance of these coatings was tested using linear polarization in 0.5M sulfuric acid electrolyte. Results showed that NiP - TiO 2 electroless composite coatings increased corrosion resistance of substrates.

Electrolytic and electroless coatings of Ni–PTFE composites

1998 ◽  
Vol 107 (2-3) ◽  
pp. 85-93 ◽  
Author(s):  
E Pena-Munoz ◽  
P Berçot ◽  
A Grosjean ◽  
M Rezrazi ◽  
J Pagetti
Keyword(s):  
Electroless Coatings ◽  
Ptfe Composites

Influence of cubic nanostructure additions on the properties of electroless coatings

2010 ◽  
Vol 5 (1/2) ◽  
pp. 129 ◽  
Author(s):  
Zdravka Karaguiozova ◽  
Stavri Stavrev ◽  
Tomasz Babul ◽  
Aleksander Ciski
Keyword(s):  
Electroless Coatings
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