A hollow extruder die for extruding a hollow member of a zinc-containing aluminum alloy

摘要

A hollow extruding die (1) for extruding a hollow section of a zinc-containing aluminum alloy is provided. The die (1) is protected from cracks and has an extended life, without requiring any substantial structural changes to the die (1). In the die mandrel (13) of the die a mandrel (13) is connected by bridges (19) with an outer cylindrical member (11). The bridges (19) have a tapered projection (23) facing toward the mandrel (13). A 3mm thick coating (25) composed of a nickel alloy is bonded on the surface of the projection (23) by padding the welding material. Instead of coating the bridges (119), a covering (125) can be attached to the surface of the bridges (119). To receive the covering (125), an engaging groove (127) extends from the root of the mandrel (113) and along the surface of the bridges (119) to the outer cylindrical member (111) of the die mandrel (101). The covering (125) is composed of the same steel material as that of the die (101) or of the nickel alloy. The covering (125) has a through hole (125b) for receiving the mandrel (113) formed on the base. At the opposite sides of the through hole (125b), the covering (125) has projecting portions that are disposed parallel to the mandrel and the covering is tapered along the bridges.