Electroless Ni-P-Cg(Graphite)-SiC Composite Coating on Cast AlSi Alloy

The study presents the electroless N-P-Cg-SiC composite coating on cast AlSi (ADC12) alloy where the bath temperature is maintained at 90°C, pH level is controlled between 4.5 to 5.0 and stirred at 450 rpm with mechanical stirrer to avoid particles sedimentation. The increase of the coating film thickness is very insignificant after one hour of coating duration. This outcome is supposed to be due to inconsistent chemical concentration in the plating bath after this period. The nominal coating thickness of 39 μm is achieved after the substrate is immersed for 1 hour in four consecutive plating baths, respectively. The coating film is also successfully adhered to the substrate surface with the SiC and Cgparticles are homogenously distributed.

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Effect of Heat Treatment on Ni-P-Cg(Graphite)-SiC Composite Coated Cast AlSi Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.795.545 ◽

2013 ◽

Vol 795 ◽

pp. 545-549

Author(s):

M.M. Mohtar ◽

Z.M. Ripin ◽

Z.A. Ahmad

Keyword(s):

Heat Treatment ◽

Surface Roughness ◽

Surface Morphology ◽

Coating Film ◽

Average Surface Roughness ◽

Micro Hardness ◽

Average Surface ◽

Treatment Processes ◽

Alsi Alloy ◽

Electroless Ni

The study presents the effect of heat treatment on electroless N-P-Cg-SiC composite coated cast AlSi (ADC12) alloy. No significant changes are noted on the average surface roughness and surface morphology of the coating film with different heat treatment processes. The growth of the hard Ni3P phase in the electroless Ni-P-Cg-SiC composite coating after heat treatment at 400°C for one hour strongly enhance the micro hardness of the AlSi-alloy (ADC12) surface from originally 101HV to 689HV. However, the micro hardness of the cast AlSi-alloy substrate decreases form 100HV to 60HV.

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A New Route for Direct Electroless Ni-P Plating on Magnesium Alloys

VNU Journal of Science Natural Sciences and Technology ◽

10.25073/2588-1140/vnunst.4507 ◽

2017 ◽

Vol 33 (2) ◽

Author(s):

Bùi Xuân Vương

Keyword(s):

Corrosion Resistance ◽

Magnesium Alloys ◽

Substrate Surface ◽

Nickel Sulfate ◽

Plating Bath ◽

High Adhesion ◽

Pickling Solution ◽

Salt Component ◽

Coarse Surface ◽

Electroless Ni

This report describes a new route for direct electroless Ni-P plating on magnesium alloys using nickel sulfate as the main salt component. The surface morphology, chemical composition and corrosion resistance of coatings were determined using SEM, EDX and electrochemical polarization techniques. Ni-P coatings with good corrosion resistance and high adhesion were obtained using this route and improved pretreatments. A mixture of H3PO4 and HNO3 was used as a pickling solution for Mg substrate pretreatment. A coarse surface was produced via the developed pickling procedure. A mechanical occlusive force is believed to exist between the coatings and the substrates. Twice activations, K4P2O7 and NH4HF2 as activation components, respectively, were applied for the pretreatment of magnesium alloy plating. An optimal F/O ratio on the Mg substrate surface was obtained by this pretreatment method. The activation film has insoluble partial fluorides which can depress the active points on substrate surface against the reaction of Mg with Ni2+ and H+ in the plating bath. A highly stable bath with pH 5 buffer was identified. The advantages of the developed process include chromium-free, low fluoride, and high bath stability. It is applicable for the production of motorcycle part plating.

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Optimization of Electroless Ni-P-Nano-TiO2 Coating Parameters Using Taguchi Method for Corrosion Performance

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.813-814.95 ◽

2015 ◽

Vol 813-814 ◽

pp. 95-100 ◽

Cited By ~ 2

Author(s):

T.R. Tamilarasan ◽

R. Sathish Kumar ◽

R. Rajendran ◽

G. Rajagopal

Keyword(s):

Experimental Study ◽

Steel Substrate ◽

Low Carbon Steel ◽

Bath Temperature ◽

Low Carbon ◽

Corrosion Performance ◽

Tafel Polarization ◽

Polarization Technique ◽

Ph Level ◽

Electroless Ni

This article considers an experimental study of Taguchi’s parameters design to maximize the corrosion resistance of electroless Ni-P-nano-TiO2 on low carbon steel substrate. The experiments were carried out based on Taguchi’s L9 orthogonal array considering four coating parameters of three levels each namely, Bath Temperature, pH of bath, Bath Loading, and concentration of TiO2. Scanning Electron Microscope (SEM) equipped with Energy Dispersive X-ray Spectroscopy (EDS) facilitated the study of the surface morphology and the chemical composition of the coatings. Corrosion performance of the deposits was evaluated by Tafel polarization technique in 3.5 wt. % of NaCl solution. The observation shows that pH level has more significant influence on the corrosion behavior of the composite deposit. The experimental study revealed that the optimum conditions are A3B3C2D1 (Temperature of 88° C, pH of 6, bath loading of 0.5 dm2/l, and TiO2 concentration of 2 g/l).

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Effects of Surfactant Agent and PTFE Content on Surface Morphology and Microstructure of Ni-P-PTFE Composite Coating

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.625.198 ◽

2012 ◽

Vol 625 ◽

pp. 198-201

Author(s):

Chuan Qi Fu ◽

Xu He ◽

Zhou Wang

Keyword(s):

Surface Morphology ◽

Composite Coating ◽

Surfactant Concentration ◽

Composite Coatings ◽

Ultrasonic Frequency ◽

Plating Bath ◽

X Ray ◽

Ptfe Composite ◽

Electroless Ni ◽

Scanning Electron

Effects of surfactant, PTFE concentration in plating bath on surface morphology and the microstructure of electroless Ni-P-PTFE composite coatings were investigated in this study. The dependence of microstructure and distribution of PTFE particles in composite coatings upon surfactant agent and PTFE content in the plating bath were reported. Also, effects of ultrasonic frequencies on PTFE content in the coatings were discussed. The surface morphology and microstructure of the composite coatings were analyzed using scanning electron microscope (SEM) and X-ray dialysis (XRD), respectively. The results obtained are indicating that surfactant and PTFE concentration in the plating bath have a great impact on PTFE content in the coatings, the population of PTFE in the coatings proved to increase with increasing surfactant concentration properly. In addition, ultrasonic frequency could change the PTFE content in the coating. The composite coating shows different surface morphology and microstructure in various surfactant concentrations, PTFE concentrations and ultrasonic frequencies.

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In Situ Diagnostics of Vuv Laser Cvd of Semiconductor Interfaces by Ftir Spectroscopy and Spectroscopic Ellipsometry

MRS Proceedings ◽

10.1557/proc-397-581 ◽

1995 ◽

Vol 397 ◽

Cited By ~ 1

Author(s):

M. Barth ◽

J. Knobloch ◽

P. Hess

Keyword(s):

Film Thickness ◽

Bulk Material ◽

Substrate Surface ◽

Cluster Formation ◽

Interface Layer ◽

Native Oxide ◽

Initial Growth ◽

Difference Spectra ◽

Si Substrates

ABSTRACTThe growth of high quality amorphous hydrogenated semiconductor films was explored with different in situ spectroscopic methods. Nucleation of ArF laser-induced CVD of a-Ge:H on different substrates was investigated by real time ellipsometry, whereas the F2 laser (157nm) deposition of a-Si:H was monitored by FTIR transmission spectroscopy. The ellipsometric studies reveal a significant influence of the substrate surface on the nucleation stage, which in fact determines the electronic and mechanical properties of the bulk material. Coalescence of initial clusters occurs at a thickness of 16 Å for atomically smooth hydrogen-terminated c-Si substrates, whereas on native oxide covered c-Si substrates the bulk volume void fractions are not reached until 35 Å film thickness. For the first time we present a series of IR transmission spectra with monolayer resolution of the initial growth of a-Si:H. Hereby the film thickness was measured simultaneously using a quartz crystal microbalance with corresponding sensitivity. The results give evidence for cluster formation with a coalescence radius of about 20 Å. Difference spectra calculated for layers at different depths with definite thickness reveal that the hydrogen-rich interface layer stays at the substrate surface and does not move with the surface of the growing film. The decrease of the Urbach energy switching from native oxide to H-terminated substrates suggests a strong influence of the interface morphology on the bulk material quality.

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The friction and wear properties of electroless Ni-polytetrafluoroethylene composite coating

Thin Solid Films ◽

10.1016/0040-6090(94)90883-4 ◽

1994 ◽

Vol 245 (1-2) ◽

pp. 98-103 ◽

Cited By ~ 21

Author(s):

Lai-Gui Yu ◽

Xu-Shou Zhang

Keyword(s):

Composite Coating ◽

Friction And Wear ◽

Wear Properties ◽

Friction And Wear Properties ◽

Electroless Ni

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High temperature wear of an electroless Ni–P–BN (h) composite coating

Surface and Coatings Technology ◽

10.1016/s0257-8972(02)00663-1 ◽

2003 ◽

Vol 163-164 ◽

pp. 578-584 ◽

Cited By ~ 45

Author(s):

O.A León ◽

M.H Staia ◽

H.E Hintermann

Keyword(s):

High Temperature ◽

Composite Coating ◽

High Temperature Wear ◽

Electroless Ni

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Dependence of Film Thickness on Properties of Al Doped ZnO Thin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.194-196.2305 ◽

2011 ◽

Vol 194-196 ◽

pp. 2305-2311

Author(s):

Ying Ge Yang ◽

Dong Mei Zeng ◽

Hai Zhou ◽

Wen Ran Feng ◽

Shan Lu ◽

...

Keyword(s):

Thin Films ◽

Film Thickness ◽

Electrical Parameter ◽

Substrate Surface ◽

Rf Magnetron Sputtering ◽

Thickness Effect ◽

Visible Range ◽

Glass Substrates ◽

Doped Zno

In this study high quality of Al doped ZnO (ZAO) thin films were prepared by RF magnetron sputtering on glass substrates at room temperature in order to study the thickness effect upon their structure, electrical and optical properties. XRD results show that the films are polycrystalline and with strongly preferred (002) orientation perpendicular to substrate surface whatever the thickness is. The crystallite size was calculated by Williamson-Hall method, while it increases as the film thickness increased. The lattice stress is mainly caused by the growth process. Hall measurements revealed electrical parameter very dependent upon thickness when the thickness of ZAO film is lower than 700 nm. The resistivity decreased and the carrier concentration and Hall mobility increases as the film thickness increased. When film thickness becomes larger, only a little change in the above properties was observed. All the films have high transmittance above 90% in visible range. Red shift of the absorption edge was observed as thickness increased. The optical energy bandgap decreased from 3.41eV to 3.30 eV with the increase of film thickness.

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Microstructural characteristics of SiC-B4C reinforced laser alloying composite coatings

Science and Engineering of Composite Materials ◽

10.1515/secm-2012-0164 ◽

2013 ◽

Vol 20 (4) ◽

pp. 307-310

Author(s):

Li Wei

Keyword(s):

Wear Resistance ◽

Composite Coating ◽

Fine Particles ◽

Composite Coatings ◽

Substrate Surface ◽

Laser Alloying ◽

Wear Process ◽

High Microhardness ◽

Deep Plowing ◽

Coating Matrix

AbstractA hard SiC-B4C reinforced composite coating was fabricated by laser alloying of SiC-B4C+Al-Sn-Mo-Y2O3 mixed powders on a Ti-3Al-2V alloy. Al-Sn-Mo mixed powders were first used in the laser alloying technique to improve the wear resistance of titanium alloys. Proper selection of the laser alloying process parameters allows us to obtain a composite coating with a metallurgical combination with substrate. Under the action of Mo, fine particles with high microhardness were produced in the coating matrix and also hindered the formation of adhesion patches and deep plowing grooves during the sliding wear process, leading to the improvement of wear resistance of a titanium alloy substrate surface.

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