Copper-based alloys and their use for infiltration of powder metal parts

Abstract

Described are wrought forms of copper alloys for infiltrating powder metal parts, the method for preparing the copper alloys and their wrought forms, the method for their infiltration into a powder metal part, and the infiltrated metal part infiltrated with the novel alloys having a generally uniform distribution of copper throughout and exhibiting high transverse rupture strength, tensile strength and yield strength. Infiltrated metal parts prepared by infiltrating powder metal parts with reduced amounts of the novel infiltrant typically weigh less and have superior strengths compared to similarly prepared infiltrated metal parts prepared with standard methods and conventional infiltration.

1 . A material for infiltrating a powder metal part comprising a copper alloy having a homogeneous wrought form, wherein the alloy contains: a) at least about 85 weight % copper; and b) about 0.5 to about 3.5 weight % iron. 
   
   
       2 . The material of  claim 1 , wherein the copper alloy further comprises: c) about 0.5 to about 5.5 weight % manganese, and d) about 0.5 to about 5.5 weight % zinc. 
   
   
       3 . The material of  claim 2 , wherein the copper alloy contains at least about 90 weight % copper. 
   
   
       4 . The material of  claim 2 , wherein the wrought form is selected from the group consisting of a disk, a ring, a sheet, a wafer, a wire segment, and a washer. 
   
   
       5 . The material of  claim 4 , wherein the form is a wire segment. 
   
   
       6 . A method for preparing an infiltration alloy comprising:
 a) forming a mixture comprising at least about 85 weight % copper, about 0.5 to about 3.5 weight % iron, about 0.5 to about 5.5 weight % manganese, and about 0.5 to about 5.5 weight % zinc;   b) heating the mixture to a temperature sufficient to form a homogeneous molten mass; and   c) transforming the molten mass into a homogeneous wrought form capable of being adapted to contact a surface of a powder metal part for the purpose of infiltrating the metal part.   
   
   
       7 . The method of  claim 6 , wherein transforming the molten mass comprises:
 a) transferring the molten mass into a mold;   b) solidifying the molten mass to form a billet; and   c) extruding the billet to provide the alloy in a substantially homogeneous wrought form.   
   
   
       8 . The method of  claim 7 , wherein the billet is heated to an elevated temperature below its melting point prior to extruding. 
   
   
       9 . The method of  claim 8 , wherein the mixture is heated to a temperature of at least about 1150° C. 
   
   
       10 . The method of  claim 8 , wherein the wrought form is a rod. 
   
   
       11 . The method of  claim 8 , wherein the wrought form is a tube. 
   
   
       12 . The method of  claim 8 , wherein the wrought form is a sheet. 
   
   
       13 . The method of  claim 10 , wherein the rod is cut across its longitudinal axis to form a disk adapted to contact a surface of a powder metal part. 
   
   
       14 . The method of  claim 11 , wherein the tube is cut across its longitudinal axis to form a washer adapted to contact a surface of a powder metal part. 
   
   
       15 . The method of  claim 12 , wherein the sheet is transformed into a wafer having a form adapted to contact a surface of a powder metal part. 
   
   
       16 . The method of  claim 10 , wherein the rod is drawn to form a wire. 
   
   
       17 . The method of  claim 16 , wherein the wire is cut into a segment and the segment shaped to conform to a surface of a powder metal part. 
   
   
       18 . The method of  claim 17 , wherein the segment is conformed to a torus shape.