Changes in Flow Velocity and Metal Flow in Direct Extrusion of Aluminum Alloy

抄録

This study experimentally examines the effects of changes in flow velocity at the die cavity during extrusion and investigates the mechanism of their occurrence. The die has two cavities of different diameters. One of the cavity serves as the velocity standard cavity and has a fixed diameter (D₁=6.0mm), while the other cavity serves as the velocity comparison cavity and had different diameter (D₂=6.0, 7.3, 8.5, and 10.4mm). Flow velocity at die cavities during extrusion is evaluated by the average flow velocity (D₁; V₁, D₂; V₂) calculated by the extrusion time and the extruded profile length for every 10mm of ram stroke. And changes in flow velocity are evaluated by flow velocity ratio (V₂/V₁). As a result, the flow velocity ratio (V₂/V₁) change occurs during the initial and end stages of the extrusion process due to the change of metal flow within the container.