Measurement of Cyclic Stresses in High Temperature Range Using Nickel Electroplating : 3rd Report, Application of a Sulfamate Bath

Using an electroplated nickel, a fundamental research for measurement of cyclic stresses in high temperature range is carried out. The plating used consists of two layers, namely, a preliminary deposit of alkaline copper in a copper cyanide bath and a nickel deposit in a sulfamate bath. The plating conditions suitable for the present purpose are proposed. In the high temperature range from 125°C to 200°C, crystal grains of deposited nickel are developed by cyclic stresses above a certain magnitude. Consequently, micro-flecks occur on the surface of deposits depending on the magnitude of applied cyclic stresses. The stress concentration factors in grooved shafts under bending are obtained at 160°C and 180°C. The results are compared with the theoretical and experimental results obtained previously.