The aluminum profile filling and extrusion stage starts with the extrusion shaft exerting pressure on the ingot in the extrusion barrel. The ingot is upset in the extrusion barrel and fills the extrusion barrel and die hole. The extrusion force rises linearly to the maximum value. , belongs to the filling and extrusion stage, as shown in area 1 in Figure 2-27. The way the metal flows is related to the type of extruder (vertical or horizontal) and the shape of the extrusion die (flat or cone).
In the vertical extruder, the ingot is loaded into the extrusion barrel, and a uniform gap exists between the ingot and the inner wall of the extrusion barrel. Extrusion on a vertical extruder can be considered as metal flow basically falling into these two situations.
The flow behavior of the ingot in the filling and extrusion stage of the horizontal extruder is similar to that of the vertical extruder. However, the ingot in the horizontal extruder must have surface contact with the extrusion barrel due to its own weight, and the billet will be in contact with the extrusion barrel along with the filling. As the process continues, the contact surface between the ingot and the extrusion barrel becomes larger and larger. In addition to the deformation flowing into the gap between the ingot and the extrusion barrel during the filling process, the contact surface will gradually produce a flow trend along the circumferential direction of the ingot.
