Sheet Forming and Porging Of Zn-Al alloys

Abstract

<p>A brief introduction to superplasticity is presented.</p> <p>The forming of superplastic sheet into a rectangular trough is examined and the thickness distribution theoretically determined. Figures, dependent on the height to width ratio of the trough, are presented of the thickness variation against a suitable geometric parameter.</p> <p>Experiments have been performed on the forming of superplastic Zn-Al into a flat bottomed cylindrical cavity. A semi-empirical analysis based on the theoretical work of Cornfield and Johnson is presented and the theoretical and experimental thickness distributions compared.</p> <p>The closed die forging of superplastic and conventional Zn-Al eutectoid alloys is examined. The results of experiments are presented and a two phase forging cycle, suitable for rate dependent materials, is presented.</p>