A Study of Cracking in Chromium Deposits

Abstract

An account is given of an experimental exploration of cracking in chromium deposits applied from solutions of conventional compositions at various temperatures and current densities. Some observations have been made of the thickness of deposit at which cracking first occurs, of the relation between cracks and striations parallel to the basis metal apparent in etched cross-sections of deposits, and of stress as a function of deposit thickness. From very small thicknesses up to the point at which cracking occurs, stress remains approximately constant or decreases slightly. At approximately the thickness at which cracking begins, the first of a series of striations is formed, the majority of cracks terminating on or close to striations. At approximately the same thickness the mean stress begins to decrease rapidly. It is tentatively suggested that cracking may be due to a reduction in tensile strength associated with structural abnormalities in the region of the striations.