A device for determination of residual stresses in galvanic coatings from the measured longitudinal deformation of a strip substrate

摘要

A method was elaborated for the determination of residual stresses in the galvanic coating by measuring the longitudinal deformation of a straight strip (ribbon) and of a cylindrical (wire) substrate. For this purpose an experimental measuring system was designed. The experiments were carried out using a nickel coating deposited bilaterally from Watt's electrolyte on a copper or brass strip substrate, and initial stresses were calculated. The strip substrate was fixed by one end and loaded with a calibrated weight on the other. The longitudinal displacement of the free end of substrate, depending on coating thickness, was determined by measuring the deformation of the elastic element. The effect of the rigidity of an elastic element on initial stresses was investigated. The results are compared with the literature data.