scholarly journals Effect of Deposition Time on the Morphological Features and Corrosion Resistance of Electroless Ni-High P Coatings on Aluminium

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
N. Sridhar ◽  
K. Udaya Bhat
Keyword(s):  
Corrosion Resistance ◽  
Electroless Deposition ◽  
Deposition Time ◽  
Substrate Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Energy Dispersive Spectroscope ◽  
Electroless Ni ◽  
Limiting Value ◽  
Scanning Electron

High phosphorus Ni-P alloy was deposited on aluminium substrate using electroless deposition route. Using zincating bath, the surface was activated before deposition. Deposition time was varied from 15 minutes to 3 hours. Deposit was characterised using scanning electron microscope with energy dispersive spectroscope, X-ray diffraction, and microhardness tester. The corrosion resistance was measured using Tafel extrapolation route. The medium was aqueous 5% HNO3 solution. The analysis showed that the deposit consisted of nodules of submicron and micron scale. The predominant phase in the deposit was nickel along with phosphides of nickel. Compared to substrate material, deposit showed higher hardness. With increase in deposition time, the deposit showed more nobleness in 5% HNO3 solution and nobleness reached a limiting value in 1 hour deposition time.

Evaluation of Corrosion Properties of Electroless NiP/Nano-SiC Composite Coatings

2011 ◽  
Vol 471-472 ◽  
pp. 203-208
Author(s):  
Arman Zarebidaki ◽  
Saeed Reza Allahkaram
Keyword(s):  
Corrosion Resistance ◽  
Composite Coatings ◽  
Energy Dispersive Spectrometer ◽  
Nano Particles ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
X Ray ◽  
Electroless Ni ◽  
Different Content ◽  
Scanning Electron

Ni-P/nano- SiC composite coatings were deposited in different concentrations of SiC nano-particles in the bath. The hardness and corrosion resistance of the composite coatings with different content of SiC nano-particles were measured. Moreover, the structure of the composite coatings was investigated by means of X-ray diffraction (XRD), while their morphologies and elemental composition were analyzed using scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS). Results showed that co-deposited SiC nano-particles contributed to increase the hardness but corrosion resistance of electroless Ni-P coatings decreased due to agglomeration of nano-particles and increasing porosity of coatings.

ELECTROLESS DEPOSITION OF Ni-P ALLOYS ON CENOSPHERES BY USING SILVER AS THE CATALYST

2006 ◽  
Vol 20 (12) ◽  
pp. 715-723
Author(s):  
JIAN XU ◽  
WEIHAO XIONG ◽  
AIXIANG ZENG
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Energy Dispersive Spectroscopy ◽  
Electroless Deposition ◽  
Coating Process ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
X Ray ◽  
Electroless Ni ◽  
Scanning Electron

Electroless deposition of Ni-P alloys on cenospheres is demonstrated in the present investigation. AgNO 3 is used as an activator to replace the conventional PdCl 2 activator and [Formula: see text] in the coating bath is used as the reducing agent to replace Sn 2+ in order to lower the overall cost of the coating process. The coated cenospheres are characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and powder X-ray diffraction (XRD). It shows that Ni-P alloys uniformly deposit on the surface of the cenospheres under experimental conditions. The possible mechanism of electroless Ni-P alloys coating of cenospheres by using silver as the catalyst is suggested.

Influence of Fly Ash on Corrosion Resistance of Refractory Forsterite-Spinel Ceramics

2021 ◽  
Vol 325 ◽  
pp. 181-187
Author(s):  
Martin Nguyen ◽  
Radomír Sokolář
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Fly Ash ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transition Zones ◽  
Refractory Ceramics ◽  
Scanning Electron

This article examines the influence of fly ash on corrosion resistance of refractory forsterite-spinel ceramics by molten iron as a corrosive medium. Fly ash in comparison with alumina were used as raw materials and sources of aluminium oxide for synthesis of forsterite-spinel refractory ceramics. Raw materials were milled, mixed in different ratios into two sets of mixtures and sintered at 1550°C for 2 hours. Samples were characterized by X-ray diffraction analysis and thermal dilatometric analysis. Crucibles were then made from the fired ceramic mixtures and fired together with iron at its melting point of 1535°C for 5 hours. The corrosion resistance was evaluated by scanning electron microscopy on the transition zones between iron and ceramics. Mixtures with increased amount of spinel had higher corrosion resistance and mixtures with fly ash were comparable to mixtures with alumina in terms of corrosion resistance and refractory properties.

Tribological Performance Optimization of Electroless Nickel Coatings Under Lubricated Condition

2018 ◽  
pp. 250-280 ◽  
Author(s):  
Santanu Duari ◽  
Arkadeb Mukhopadhyay ◽  
Tapan Kumar Barman ◽  
Prasanta Sahoo
Keyword(s):  
Performance Optimization ◽  
Friction And Wear ◽  
Electroless Nickel ◽  
Heat Treating ◽  
Wear Depth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heat Treated ◽  
Electroless Ni ◽  
Scanning Electron

The present chapter aims to determine optimal tribo-testing condition for minimum coefficient of friction and wear depth of electroless Ni-P, Ni-P-W and Ni-P-Cu coatings under lubrication using grey relational analysis. Electroless Ni-P, Ni-P-W and Ni-P-Cu coatings are deposited on AISI 1040 steel substrates. They are heat treated at suitable temperatures to improve their hardness. Coating characterization is done using scanning electron microscope, energy dispersive X-Ray analysis and X-Ray diffraction techniques. Typical nodulated surface morphology is observed in the scanning electron micrographs of all the three coatings. Phase transformation on heat treating the deposits is captured through the use of X-Ray diffraction technique. Vicker's microhardness of the coatings in their as-deposited and heat treated condition is determined. Ni-P-W coatings are seen to exhibit the highest microhardness. Friction and wear tests under lubricated condition are carried out following Taguchi's experimental design principle. Finally, the predominating wear mechanism of the coatings is discussed.

Synthesis and Properties of Electroless Ni-P-W/Nano-Al2O3 Composite Coatings Deposited on Sintered NdFeB Permanent Magnet

2011 ◽  
Vol 306-307 ◽  
pp. 901-906 ◽  
Author(s):  
Huan Ming Chen ◽  
Ya Hong Gao ◽  
Qiong Lv ◽  
Dong Yang ◽  
Xin Xin Lin
Keyword(s):  
Corrosion Resistance ◽  
Permanent Magnet ◽  
Composite Coatings ◽  
Alloy Coating ◽  
X Ray Diffraction ◽  
Ndfeb Magnet ◽  
X Ray ◽  
Plating Method ◽  
Ndfeb Permanent Magnet ◽  
Electroless Ni

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.

The Effect of Accelerator Types on the Phosphated Zn-%12Ni Electrodeposite Coating

2018 ◽  
Author(s):  
Hafez Alizadeh ◽  
Amir Hanaei ◽  
Behzad Heidarshenas ◽  
Armita Shahbazkhan ◽  
Naghi Parvini Ahmadi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Phosphate Solution ◽  
Surface Porosity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nitrate And Nitrite ◽  
Coating Weight ◽  
Scanning Electron

The aim of this study is to investigate the effect of nitrate and nitrite on the weight, morphology and electrochemical properties of phosphated Zn-%12Ni electrodeposite coatings. In order to investigate the phase structure and surface morphology of samples, X-ray diffraction and scanning electron microscopy were employed. Also, to measure the corrosion resistance behavior of the coats, Potentiostat/Galvanostat test was used. The results showed that nitrite accelerator reduces coating weight and surface porosity simultaneously obtaining by phosphate solution. Furthermore, coatings being obtained by the nitrite accelerator had a higher corrosion resistance than that of the nitrate accelerator.

Research on Preparation and Properties of Al-Mn Alloy Coating in NaCl-KCl-AlCl3-NdCl3 Molten Salts

2011 ◽  
Vol 121-126 ◽  
pp. 335-339
Author(s):  
Xian Jin Yu ◽  
Li Peng Zhang ◽  
Zhi Wei Ge ◽  
Yun Hui Dong ◽  
Dang Gang Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Molten Salts ◽  
Alloy Coating ◽  
Surface Coatings ◽  
X Ray Diffraction ◽  
Pitting Potential ◽  
X Ray ◽  
Scanning Electron

Al-Mn alloy coatings were electrodeposited on an iron substrate from AlCl3-NaCl-KCl low-temperature molten salts with anhydrous MnCl2 enhanced by the addition of NdCl3.The microstructure and properties of the Al-Mn alloy coatings were investigated, and scanning electron microscopy, X-ray diffraction, and polarization curves were used to determine the composition, surface morphology, phase structure, and corrosion resistance of the obtained deposits. The results show that the surface coatings were smooth, and that the crystallites were dense and uniform when 0.23 wt% NdCl3 was added to the molten salt. An amorphous mixture of Al and Al6Mn was obtained. NdCl3 enhanced the corrosion resistance and increased the hardness of the single amorphous phase alloys. The pitting potential of the coating was approximately −1.04V, and its hardness was 392 kgf/mm2.

Corrosion Behaviour of AZ91DSm1.0 with Different Preparation Methods

2014 ◽  
Vol 1004-1005 ◽  
pp. 113-118
Author(s):  
Hong Xia Liu ◽  
Jin Liang ◽  
Jue Zhang ◽  
Xiao Lian Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Corrosion Behaviour ◽  
X Ray Diffraction ◽  
Vacuum Melting ◽  
Potentiodynamic Polarization Curve ◽  
Preparation Methods ◽  
X Ray ◽  
Scanning Electron

Corrosion behaviour of AZ91DSm1.0 with different preparation methods(vacuum melting and common melting) is investigated. X-ray diffraction(XRD), optical microscopy(OM), scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), corrosion weightless experiment and the potentiodynamic polarization curve are applied to characterize the corrosion behaviour. Results show that vacuum melting alloy possess higher corrosion resistance than common melting alloy. This is attributed to the rod-shaped Al3Sm which was formed in common melting alloy will have certain fragmentation effect on matrix that can lead to defects.

Electrochemical synthesis and properties of layer-structured polypyrrole/montmorillonite nanocomposite films

2010 ◽  
Vol 25 (4) ◽  
pp. 658-664 ◽  
Author(s):  
Chang-An Wang ◽  
Keyu Chen ◽  
Yong Huang ◽  
Huirong Le
Keyword(s):  
Deposition Time ◽  
Composite Films ◽  
Nanocomposite Films ◽  
Nanoindentation Test ◽  
Test Results ◽  
X Ray Diffraction ◽  
Free Standing ◽  
Sem Images ◽  
X Ray ◽  
Scanning Electron

Layer-structured polypyrrole/montmorillonite (PPy/MMT) naoncomposite films were synthesized by the electrodeposition method. The fabricated free-standing films consist of about 0∼2 wt% Na+-montmorillonite (NMMT). The thickness of films could be controlled by deposition time. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to observe the microstructure of the films. After MMT was introduced into the PPy matrix, the interspace between PPy chains decreased, according to the XRD results. The layered structure of the films was observed from the SEM images. Tensile and nanoindentation test results showed that the mechanical properties of the composite films were improved at low clay loading. The electrical conductivity of the films with 1.2 wt% MMT loading was increased from 3.6 to 51 S/cm, probably because of the restricted growth of PPy chains in the interspace of MMT layers.

scholarly journals Corrosion Behaviour of Zn-10Al-1.5Cu Alloy

2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
C. N. Panagopoulos ◽  
A. G. Tsopani
Keyword(s):  
Electron Microscopy ◽  
Corrosion Resistance ◽  
Corrosion Behaviour ◽  
Solution Concentration ◽  
Solution Temperature ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nacl Concentration ◽  
Scanning Electron

The corrosion behaviour of Zn-10Al-1.5Cu alloy in NaCl solution was examined. The used NaCl solution concentrations were 1M, 0.3M, and 0.003M for a constant temperature values of 7°C or 25°C or 45°C. The corrosion behaviour of this alloy was investigated under potentiodynamic corrosion conditions. The surface of the corroded alloy specimens was studied with the aid of scanning electron microscopy and X-ray diffraction techniques. It was observed that the increase of NaCl concentration in the corrosion solution for a constant value of temperature led to lower corrosion resistance of the alloy. For a constant value of solution concentration, the increase of solution temperature also led to the decrease of corrosion resistance of the same alloy.

Sign in / Sign up

Export Citation Format

Share Document