Influence of titanium carbide particles addition on the forging behaviour of powder metallurgy composite steels

Abstract

This paper evaluates some of the cold-forging features of composite steel preforms of varying titanium carbide contents during cold upsetting under triaxial stress state conditions. A complete experimental investigation is carried out on composite steel preforms of varying titanium carbide contents, namely, 3%TiC and 4%TiC with different lubricating conditions; namely, graphite and zinc stearate and no lubrication. Cylindrical compacts with aspect ratios of 0.42, 0.67, and 1.0 were prepared, sintered, and upset forged at room temperature. The measured barrel radius of curvature is found to have a circular arc because the above relationship is a straight-line one. A relationship is established between the measured barrel radius and the stress ratio parameters of (σθ/σz), (σz/σm), and (σeff/σz) determined under triaxial stress state conditions for both composite steels of varying titanium carbide content. The effect of titanium carbide particle addition in the composite steel, initial preform geometry, and lubricating conditions on the deformation behaviour has been studied, together with the densification route of the composite steel preforms during the deformation.