523 Fundamental study in direct extrusion of aluminum alloys

概要

論文の詳細を見る
This study experimentally examines the effects of changes in flow velocity at the die cavity during extrusion and investigates the mechanism of their occurrence. Dies have two cavities of different diameters. One of the cavity serves as the velocity standard cavity and has a fixed diameter (D_1=6mm), while the other cavity serves as the velocity comparison cavity and had different diameter (D_2=7.3mm, 8.5mm, 10.4mm). Flow velocity at die cavities during extrusion is evaluated by the average flow velocity (D_1; V_1,D_2; V_2) calculaed 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 (V_2/V_1 The flow velocity ratio changes during extrusion, and the following tendencies can be seen upon dividing the extrusion cycle into the initial extrusion period (flow velocity ratio R_I), the mid-extrusion period (flow velocity ratio R_M), and the end extrusion period (flow velocity ratio R_E). ・ During the initial and mid-extrusion periods, the flow velocity ratio is R_I>R_M>1,but during the end extrusion period, a rapid change in flow velocity occurs, where R_E<1. ・ The flow veloity ratio in the mid-extrusion period shows stable conditions in respect to changes in ram stroke.
一般社団法人日本機械学会の論文