Comparison of anodic dissolution, surface brightness and surface roughness of nanocrystalline nickel coatings with conventional decorative chromium coatings

This study investigate the machining operation perform by the combination of EDM and ECM process. Since in case of EDM the surface finish obtain is not as good as required so next machining operation is done by ECM. As we have, in EDM metal is removed from the workpiece through spark erosion and in ECM metal removed by anodic dissolution in the electrolyte. Both the process is done simultaneously in single machine changing the potential on anode and cathode and the medium. The EDM surface of 1μ mm Ra is improved to 0.2μ mm Ra by applying ECM. The surface roughness of a machined hole is improved to 0.07 mm Ra by applying 2 min of ECM lapping. Both the process is done simultaneously.

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Surface Effects on the Magnetic Behavior of Nanocrystalline Nickel Ferrites: The Effect of Surface Roughness and Dilution

MRS Proceedings ◽

10.1557/proc-877-s6.1 ◽

2005 ◽

Vol 877 ◽

Author(s):

H. Nathani ◽

R.D.K. Misra ◽

W.F. Egelhoff

Keyword(s):

Surface Roughness ◽

Nickel Ferrite ◽

Magnetic Measurements ◽

Magnetic Behavior ◽

Magnetic Data ◽

Zero Field ◽

Nanocrystalline Nickel ◽

Polyethylene Matrix ◽

Dilution Effects ◽

Field Cooling

AbstractThe paper describes the surface roughness and dilution effects on the magnetic behavior of nanocrystalline nickel ferrites studied by SQUID magnetometer. Two different kinds of measurements were performed: (a) zero-field cooling (ZFC) and field cooling (FC) magnetization versus temperature and (b) magnetization as a function of the applied field. The analysis of magnetic measurements indicate that while the superparamagnetic behavior is retained by nanocrystalline ferrites of different surface roughness (0.8-1.8 nm) at 300K, the hysteresis loop at 2K becomes non-squared and the coercivity increases with increase in surface roughness. This behavior is discussed in terms of broken bonds and degree of surface spin disorder. In diluted dispersion systems containing 10-40% nickel ferrite in a polyethylene matrix, the interparticle attractions continue to be dominant even when the concentration of nickel ferrite is 10 wt.% in the diluted system. The general magnetic behavior of diluted dispersion system is similar to the undiluted system; however, coercivity, remanence, and saturation magnetization are altered. These changes in the magnetic data are ascribed to magnetization interactions that encourage flux closure configuration.

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Effect of Electroplating Parameters on Microstructure of Nanocrystalline Nickel Coatings

Journal of Material Science and Technology ◽

10.1016/s1005-0302(10)60013-8 ◽

2010 ◽

Vol 26 (1) ◽

pp. 82-86 ◽

Cited By ~ 74

Author(s):

A.M. Rashidi ◽

A. Amadeh

Keyword(s):

Nanocrystalline Nickel ◽

Nickel Coatings

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Effect of Pulse Electrodeposition on Properties of Nanocrystalline Nickel Coatings

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.829.410 ◽

2013 ◽

Vol 829 ◽

pp. 410-415 ◽

Cited By ~ 1

Author(s):

Mohammad Reza Sanaeian ◽

Farzad Nasirpouri

Keyword(s):

Growth Direction ◽

Nanocrystalline Nickel ◽

Corrosion Resistant ◽

Nickel Coatings ◽

Corrosion Evaluation ◽

Watts Bath ◽

Naoh Solution ◽

Hardness Values ◽

Pc Method ◽

Deposition Conditions

In this work, nanocrystalline nickel coatings were electrodeposited from a Watts bath using direct (DC) and pulsed (PC) current. Effect of deposition conditions on the morphology, hardness, grain size, surface roughness and corrosion resistance of nickel coatings were investigated. Ni films deposited by PC method exhibited greater hardness values and smaller crystallite size compared to those deposited by DC method. A preferential crystallographic orientation or texture was found in the nickel films depending upon the electrodeposition pulse shape, as it is polycrystalline in the DC electrodeposited films, while exhibit <111> crystallographic growth direction for PC method. Corrosion evaluation results showed that the PC electrodeposited nanocrystalline Ni films have higher corrosion resistant compared to those deposited with the DC method in 2 mol/liter NaOH solution.

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