Theoretical and experimental investigations on multi-hole extrusion process

A model is proposed for estimation of ram force in a multi-hole extrusion process and a number of experiments are conducted by extruding lead metal alloy and commercially available candle wax through various dies. The model provides a good upper bound of the ram force, although the quantitative agreement between the estimated and actual lengths of extruded products through various holes of a multi-hole die is not so good. It is also observed that the flow behavior of the material during the extrusion process is different for wax and lead. The micro-hardness and uni-axial tensile tests of the extruded lead products indicate that strain-hardening is more for the products extruded through the central hole than for the products extruded through the holes near the die wall.