V.V. Artamonov* and V.P. Artamonov.
The Pavlodar State University
A simple and reliable method for the quantitative measurement of bond strength of an electroplated coating on a steel basis metal by means of an adhesive joint is suggested. The method can be used as an alternative to known ways of quantitative determination of the bond strength, and to standard methods, which assume only quality assessment of the bond strength.
Keywords: galvanic plating, electroplating, bond, steel basis metal, adhesive joint, break-off force.
One of the parameters describing the appropriate quality of electroplating is the bond strength between the plating and the basis metal. All other things being equal, corrosion protection of the basis metal is important, but the bond strength between the plated coating and the basis metal is absolutely critical.
The control of the bond strength of metallic plating with the basis metal is carried out under the Russian Standard GOST 9.302-88.1 The ordered methods are based on the distinction of physicomechanical properties of the plated metal and those of the basis metal, the method of control chosen being dependent on the type of plating. However, the standard methods - polishing, scratch-brushing, bending, coiling, etc. - enable one to assess the adhesion strength only qualitatively, based on the presence or absence of blisters or peeling.1
At the same time, in some cases there is a need for a quantitative assessment of the bond strength. Such situations arise, for example, in the process of designing new electrolytes for electrodepositing this or that kind of galvanic plating. A new electrolyte may provide a stronger bond when compared with known electrolytes. However, this advantage can only be demonstrated by determining the quantitative bond strength.
There are a number of known methods used to determine the quantitative bond strength, usually involving the measurement of the force necessary to separate the coating from the basis metal.2 However, these methods have certain disadvantages, including the difficulty of manufacturing test samples. Further, thick coatings, not less than 300 μm, are required. Because of these requirements, the results do not related to practical usage.