抄録
The bent strip method has been used by many investigators for measuring the internal stress in electrodeposits.
Although the formula, which they used for calculating the internal stress by the experiments of the above method, leads to a mean value of stress, it does not express the correct instantaneous internal stress, because the internal stress in electrodeposits always varys according to time and the instantaneous thickness of the deposit.
However, the authors presented a formula for calculating the instantaneous internal stress in the deposits, the formula could be applied for the experiments of the above method. The formula could express the instantaneous internal stress and transition point between compressive and tensile stresses exactly.
As the results of the evaluation of the behavior of internal stress in triple nickel plating, it was found that the semi-bright nickel as well as that obtained from watts bath showed tensile strength; while, the intermediate nickel from striking bath and bright nickel showed tensile strength at the initial stage of electrodeposition, but the direction of stress changed to compressive as the deposition proceeded.
Accordingly, it was concluded that the triple nickel plating was more profitable than single nickel plating in regard to the effects of internal stress in the electrodeposition.
