The growth of platinum particle supported on an acetylene black was investigated fundamentally using a potential perturbation method in phosphoric acid at 205°C and atmospheric pressure. Platinum particles in a colony were agglomerated to form one particle depending on the potential of the electrode and number of particles in the colony. Platinum dissolution and redeposition were considered to be the main reasons for the agglomeration.

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Many types of punching processes are utilized in the production of automobile parts and other components. In normal punching with a punch and a die, a sheared surface and a fractured one are usually formed on the cut surface. Here, to produce highly accurate parts, it is important to estimate the ratio of the sheared surface to the cut surface and to economically produce smooth cut surfaces, optimal tools and punching conditions must be selected within the limits of cost constraints. The finite element method (FEM) has been applied to the analysis of the ratio of the sheared surface to the fractured surface on the cut surfaces. For this, the ductile fracture criteria for the fracture initiation of the cut surface have been proposed by several researchers. It is difficult to determine the fracture criteria on the cut surface by tensile tests or bending tests because the punching process consists of many complicated steps. In this study, we apply the FEM to four punching arrangements to evaluate the ductile fracture criteria proposed by Oyane and by Cockcroft and Latham. We find that the morphology of the cut surface is affected by clearance between the punch and the die, by blank holding conditions and by ductile fracture criteria.

is investigated under fuel cell operating conditions (205 °C, 1 atm) by means of a potential perturbation method.