Investigation of Erosion–Corrosion Resistance of Electroless Ni–P–Ti Composite Coatings

2020 ◽  
Vol 6 (4) ◽  
Author(s):  
Zhi Li ◽  
Md. Aminul Islam ◽  
Zoheir Farhat
2017 ◽  
pp. 1303-1326
Author(s):  
Prasanna Gadhari ◽  
Prasanta Sahoo

Electroless nickel coatings are widely popular in various industrial sectors due to their excellent tribological properties. The present study considers optimization of coating parameters along with annealing temperature to improve microhardness and corrosion resistance of Ni-P-TiO2 composite coatings. Grey relational analysis is used to find out the optimal combination of coating parameters. From the analysis, it is confirmed that annealing temperature of the coating has the most significant effect and amount of titanium particles in the coating has some significant effect on corrosion properties of the coating. The same trend is observed in case of combined study of corrosion behavior and microhardness. The surface morphology, phase transformation and the chemical composition are examined using scanning electron microscopy, X-ray diffraction analysis and energy dispersive analysis respectively. The Ni-P-TiO2 composite coating revealed nodular structure with almost uniform distribution of titanium particles and it turns in to crystalline structure after heat treatment.


2011 ◽  
Vol 306-307 ◽  
pp. 901-906 ◽  
Author(s):  
Huan Ming Chen ◽  
Ya Hong Gao ◽  
Qiong Lv ◽  
Dong Yang ◽  
Xin Xin Lin

The Ni-P-W/nano-Al2O3composite coatings were deposited on the surface of sintered NdFeB permanent magnet by electroless plating method. The morphology and the phases of Ni-P-W/nano-Al2O3composite coatings were investigated using scanning electron microscopy and X-ray diffraction respectively. The hardness and the corrosion resistance of the composite coatings were also tested. The results indicated that the composite coatings morphology appears closely nodules morphology, and the microhardness increases with increasing incorporation of Al2O3ratio. Compared with NdFeB magnet and Ni-P-W alloy coatings, the corrosion resistance of the composite coatings was superior to that of the NdFeB magnet and the alloy coating obviously.


2012 ◽  
Vol 05 ◽  
pp. 810-816 ◽  
Author(s):  
S.R. Allahkaram ◽  
T. Rabizadeh

The process of electroless plating Ni - P and Ni - P /nano- SiO 2 on API-5L X65 carbon steels was improved. The Ni - P /nano- SiO 2 composite coatings were prepared from the bathes containing different concentrations of nano- SiO 2 particles. The coatings surface and morphologies were observed via scanning electron microscopy (SEM). The chemical compositions were analyzed by EDAX. The corrosion behaviors were evaluated by electrochemical impedance spectroscopy tests. The experimental results indicated that SiO 2 nano-particles co-deposited but some agglomeration occurred. Micro-hardness of electroless Ni - P - SiO 2 composite coatings increased due to the existence of nano-particles. Corrosion tests showed that both electroless Ni - P and Ni - P /nano- SiO 2 composite coatings demonstrated significant improvement of corrosion resistance of substrate in salty atmosphere and latter coating type appeared to offer a better corrosion protection.


2016 ◽  
Vol 23 (3) ◽  
pp. 309-314
Author(s):  
M. Edwin Sahayaraj ◽  
J.T. Winowlin Jappes ◽  
I. Siva ◽  
N. Rajini

AbstractElectroless nickel coating treatment improves the corrosion resistance of mild steel. This work aims at studying the corrosion behavior of electroless Ni-P/TiO2 composite and multilayer coatings applied to the mild steel substrate as their as-plated state and furnace annealed at various temperatures and compared both the coatings’ corrosion performance. The corrosion behavior of the deposits was evaluated by potentiodynamic polarization studies in 3.5 wt% sodium chloride solution. The results showed that the corrosion resistance of the multilayer coating was two times higher compared to the composite coatings. Further, the corrosion mechanism was discussed in terms of microstructure, phase transformation, grain size, and microstrain.


2010 ◽  
Vol 160-162 ◽  
pp. 1464-1468
Author(s):  
Feng Hou ◽  
Hong Xu ◽  
Yu Lin Dai ◽  
Zhi Yan Yao ◽  
Cao Yan

Over the last ten years, sulfuric acid dewpoint corrosion has become a more important concern in refinery furnaces since sulfur levels in fuels have increased. Electroless nickel phosphorous coating is one of the most widely used industrial coatings owing to its good corrosion resistance in many highly corrosive environments. In this work, electroless Ni-P-SiO2 composite coatings were prepared on AISI 1020 carbon steel. And the corrosion behaviors of Ni-P-SiO2, Ni-P coatings and carbon steel substrate were evaluated by immersion, electrochemical tests in 5%wt sulfuric acid solution, and dewpoint corrosion tests in simulated furnace flue gas. The experimental results indicated that corrosion resistance properties of Ni-P-SiO2 coating was best, followed by Ni-P coating and carbon steel was worst.


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