Shape of tools and quality of extrusions from aluminium and its alloys

摘要

In the work the shape of tools and extrusion defects were defined and the attempt at finding the connection between them was undertaken. Distortions and twists of the solid sections and the quality of welds in the hollow sections extruded through the porthole dies were especially emphasised. The investigations were performed for the hot extruded sections from aluminium and its alloys. The use of the pocket dies reduced significantly distortions and twists of extruded sections. It was proofed, that the local intensification of the in the vicinity of the welding chamber, that improves the quality of welds, can be achieved by the proper design of both the bridge and the face of the die insert, located under the bridge.