Properties of Chromium Coatings Deposited from "Sulpho-Chromispel-I" Electrolyte of Standard Concentration

The most important properties of reflectivity, internal stress, hardness and surface morphology of chromium coatings deposited from "Sulfo-Chromispel-I" electrolytes (250 g dm −3 CrO 3 ) are studied The effects of operating parameters and electrolyte composition are evaluated. It is establ...

Full description

Saved in:
Bibliographic Details
Published in:Transactions of the Institute of Metal Finishing 2004, Vol.82 (3-4), p.83-86
Main Author: Mantcheva, R.
Format: Article
Language:English
Subjects:
"Sulpho-Chromispel-I"
Applied sciences
brightness
chromium coatings
electrolytes
Exact sciences and technology
hardness
internal
Metallic coatings
Metals. Metallurgy
morphology
Production techniques
surface
Surface treatment
tension
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The most important properties of reflectivity, internal stress, hardness and surface morphology of chromium coatings deposited from "Sulfo-Chromispel-I" electrolytes (250 g dm −3 CrO 3 ) are studied The effects of operating parameters and electrolyte composition are evaluated. It is established that chromium coatings depositedfrom "Sulpho-Chromispel-I" electrolytes exhibit low internal stress. The current density and thickness of the coating affect the latter. Internal tension is reduced with the increase in coating thickness at current density of 50 A dm −2 , which is very favourable for depositing thick functional chromium layers. The reflectivity is affected by the concentration of iodide and cathodic current density. At current densities up to 35 A dm −2 the higher the iodide concentration, the brighter the coating. With increased current densities the coatings produced are coarser and their brightness is reduced. Small amounts of sulphuric acid (4-20 cm 3 dm −3 ) improve the brightness. The hardness of the coatings deposited from the electrolytes studied is less than that of coatings deposited from a standard sulphate bath-300-400 kg mm −2 . The roughness grade is 0.5-0.6 mm. The coatings deposited from "Sulpho-Chromispel-I" electrolytes are bright with low tensile stress and moderate hardness. They are deposited at ambient temperature over a wide interval of current density, which is rather advantageous from a technological point of view.
ISSN:0020-2967
1745-9192
DOI:10.1080/00202967.2004.11871566