Phenomenon of barrelling in zinc solid cylinders during cold upset forming

Abstract

Experiments were carried out to generate data on the upset forging of solid cylinders of annealed zinc. The curvatures of the barrelled Zinc cylinders physically measured were found to conform one to one with the calculated values using the experimental data. The calculations were made on the assumption that the curvature of the barrel followed the geometry of

<span style="font-size:14.0pt;line-height:115%;font-family:" times="" new="" roman";="" mso-fareast-font-family:"times="" roman";color:black;mso-ansi-language:en-in;="" mso-fareast-language:en-in;mso-bidi-language:hi"="" lang="EN-IN">circular arc. It was further found that the measured radius of curvature of the barrel exhibited a straight line relationship against the new geometrical shape factor irrespective of the aspect ratios of the cylinders. Empirical relations were found to exist between the measured radius of curvature of the barrel and independently with other variables like hydrostatic stress and stress ratio parameter.</span>