Extrusion die for hot hydrostatic extrusion of aluminum and aluminum alloys

摘要

A die for use in a hot hydrostatic extrusion process, in which a billet comprised of aluminum or an aluminum alloy or a billet having aluminum and an aluminum alloy at its outer periphery is preheated and charged into a container whereupon extrusion is carried out by means of a pressure medium, said die comprising a plurality of stepped conical portions serving as approach portions to the die outlet; said conical portions having conical surfaces whose opening angles increase from the inlet of the die toward the outlet thereof, said conical surface which is closest to said inlet having an opening angle of less than 60 degrees, and the difference between the opening angles between adjacent conical surfaces being less than 90 degrees.