Patent ID: 6212934
Filing Date: 2001-04-10
Classification: B21D,B21J

Abstract:
A method of cold forging with a reusable die comprising the following steps:a) forming a basic die structure comprising a die frame, a bottom lid, a plurality of strut spacers affixed to said bottom lid, a plastic film with a refractory heat insulating layer positioned on the top of said die frame and conforming in shape to a shape of a workpiece to be formed, an upper filler layer formed from a plurality of flexible sheets, and a lower filler layer formed from a plurality of sheets of steel mesh, said upper filler layer and said lower filler layer are contained in a die cavity of said die frame,b) forming a medium of penetration from an alloy with a low melting point, said alloy is poured in liquified form into said die frame, said liquified alloy penetrating and filling pores in said upper filler layer and said lower filler layer,c) cooling said alloy so that said alloy is solidified, said alloy thereby encapsulating said upper filler layer and said lower filler layer,d) cold forging a workpiece into a desired shape in said reusable die, ande) melting and recovering said alloy so that said alloy can be used to form a new die.