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 method for infiltrating a powder metal part, the method comprising: a) providing the powder metal part; b) providing a copper alloy having a homogeneous wrought form adapted to contact a surface of the powder metal part, c) contacting the alloy with a surface of the powder metal part; and d) heating the alloy and the powder metal part to a temperature sufficient to cause the alloy to melt and infiltrate the powder metal part, wherein the alloy comprises: (i) at least about 85 weight % copper; and ii) about 0.5 to about 3.5 weight % iron. 
     
     
         2 . The method of  claim 1 , wherein the alloy contains at least about 90 weight % copper. 
     
     
         3 . The method of  claim 1 , wherein the powder metal part is an iron-based powder metal part. 
     
     
         4 . The method of  claim 3 , wherein the powder metal part is a sintered metal part. 
     
     
         5 . The method of  claim 1 , wherein the surface of the powder metal part is an upper surface. 
     
     
         6 . The method of  claim 1 , wherein the temperature is at least about 800° C. 
     
     
         7 . The method of  claim 1 , wherein the homogeneous wrought form is a wire segment. 
     
     
         8 . The method of  claim 7 , wherein the wire segment has a generally torus shaped form. 
     
     
         9 . The method of  claim 1 , wherein the homogeneous wrought form is a disk. 
     
     
         10 . The method of  claim 1 , wherein the homogeneous wrought form is a washer. 
     
     
         11 . The method of  claim 1 , wherein the heating is conducted at less than atmospheric pressure. 
     
     
         12 . The method of  claim 1 , wherein the heating is conducted in a highly-reducing atmosphere. 
     
     
         13 . The method of  claim 1 , wherein the homogeneous wrought form is a wafer. 
     
     
         14 . A method for infiltrating a powder metal part, the method comprising: a) providing the powder metal part; b) providing a copper alloy having a homogeneous wrought form; (c) shaping the copper alloy to conform the alloy to a surface of the powder metal part; d) contacting the shaped copper alloy with the surface of the powder metal part; and e) heating the alloy and the powder metal part to a temperature sufficient to cause the alloy to melt and infiltrate the powder metal part, wherein the alloy comprises: (i) at least about 85 weight % copper; and ii) about 0.5 to about 3.5 weight % iron. 
     
     
         15 . The method of  claim 14 , wherein shaping the copper alloy to conform to the surface of a powder metal part involves a shaping process selected from the group consisting of forming a wire coil, forming a disk, forming a washer, forming a wafer, forming a sheet, and forming a ring. 
     
     
         16 . The method of  claim 15 , wherein the shaping process selected involves forming a wire coil. 
     
     
         17 . A method for infiltrating a powder metal part, the method comprising: a) providing a copper alloy in contact with a surface of the powder metal part, and (b) heating the alloy and the powder metal part to a temperature sufficient to cause the alloy to melt and infiltrate the powder metal part;
 wherein the alloy has a homogeneous wrought form and a shape adapted to contact a surface of the powder metal part, and   wherein the alloy comprises: (i) at least about 85 weight % copper; and ii) about 0.5 to about 3.5 weight % iron.   
     
     
         18 . The method of  claim 17 , wherein providing a copper alloy in contact with a surface of the powder metal part, involves providing a copper alloy having a shape selected from the group consisting of a wire coil, a disk, a washer, a wafer, a sheet, and a ring.