EXTRUSION METAL DIE FOR ALUMINUM-BASED COMPOSITE MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide an extrusion die for aluminum-based composite material which can reduce strain in the outer diameter of a tubular product. SOLUTION: The extrusion die 10 for the aluminum-based composite material is equipped with arc-shaped pieces 15 whose inside diameter dp is larger than the diameter Dr of the forming round 33 in a chamber 31 and located close to the exit 26 of a porthole 22. Viewing from the entrance side 25 of the porthole, Ap is set to Ah×35-95%; wherein Ah is the cross section area of the exit, while Ap is the surface area of the side face of the pieces which closes the exit by the designated extent. By the method, the flow rate in the center of the exit is decreased by the pieces and its difference from the flow rate around bridges of the exit becomes less so that the strain in the outer diameter of the tubular product can be reduced. In order to suppress the strain in the outer diameter below the designated value, the surface area Ap of the pieces is set to 35-95% of the cross section area Ah of the porthole. COPYRIGHT: (C)2004,JPO&NCIPI