초록 ▼

A method and apparatus for injection molding a metal alloy wherein the alloy is maintained in a thixotropic, semi-solid state in a reciprocating extruder at temperatures above its solidus temperature and below its liquidus temperature in the presence of shearing and then injected as a thixotropic sl

A method and apparatus for injection molding a metal alloy wherein the alloy is maintained in a thixotropic, semi-solid state in a reciprocating extruder at temperatures above its solidus temperature and below its liquidus temperature in the presence of shearing and then injected as a thixotropic slurry into a mold to form a useful product. Following completion of the injection molding stroke the nozzle of the extruder is sealed by a solidifying a portion of the residue of the alloy remaining in the nozzle.

대표청구항 ▼

A method of injection molding a metallic material having dendritic properties comprising: (a) introducing said material into an extruder barrel terminating at one end in a discharge nozzle; (b) moving said material through said barrel toward an accumulation zone adjacent said nozzle; (c) heating sai

A method of injection molding a metallic material having dendritic properties comprising: (a) introducing said material into an extruder barrel terminating at one end in a discharge nozzle; (b) moving said material through said barrel toward an accumulation zone adjacent said nozzle; (c) heating said material to a temperature between its solidus and liquidus temperatures to convert said material to a semi-solid, thixotropic state; (d) shearing said material during its movement toward said accumulation zone to inhibit dendritic growth; (e) expanding said accumulation zone independently of the movement of said material into said zone and at a rate at least as great as that at which said material is moved into said accumulation zone; (f) discontinuing shearing of said material in said accumulation zone; (g) maintaining the temperature of material in said accumulation zone at a level to inhibit dendritic growth; and (h) periodically applying to material accumulated in said accumulation zone sufficient force to discharge material accumulated in said zone through said nozzle into a mold.