Development of electrodeposited Fe–Cr–P amorphous metallic alloys

The main characteristic of amorphous materials is the lack of long range crystallographic order in their structure that confers chemical and physical properties different from their crystalline counterparts. One such property is the superior corrosion resistance of certain Cr containing Fe based amorphous alloys. Conventional electrodeposition from aqueous solutions is one of the techniques that has been used to obtain these alloys. This paper represents a study of the influence of various process parameters on the composition, morphology, and properties of electrodeposited Fe– Cr–P amorphous alloy coatings. The effect of ion selective membrane, formic acid (a Cr 3+ complexant), sodium lauryl sulphate (a surfactant), and aging time of the formic acid containing bath were investigated. The results show that it is possible to obtain these coatings under certain experimental conditions. Electrochemical tests, carried out in sulphuric acid, revealed corrosion behaviour intermediate between the carbon steel substrate and the amorphous alloy.