Iron-based sintered powder metal for wear resistant applications

Abstract

A powder metal material comprises pre-alloyed iron-based powder including carbon present in an amount of 0.25 to 1.50% by weight of the pre-alloyed iron-based powder. Graphite is admixed in an amount of 0.25 to 1.50% by weight of the powder metal material. The admixed graphite includes particles finer than 200 mesh in an amount greater than 90.0% by weight of the admixed graphite. Molybdenum disulfide is admixed in an amount of 0.1 to 4.0% by weight of the powder metal material, copper is admixed in an amount of 1.0 to 5.0% by weight of the powder metal material, and the material is free of phosphorous. The powder metal material is then compacted and sintered at a temperature of 1030 to 1150° C. At least 50% of the admixed graphite of the starting powder metal material remains as free graphite after sintering.

What is claimed is: 
     
         1 . A powder metal material comprising:
 pre-alloyed iron-based powder including carbon present in an amount of about 0.25 to about 1.50% by weight of said pre-alloyed iron-based powder; and   admixed graphite.   
     
     
         2 . A powder metal material as set forth in  claim 1 , wherein said pre-alloyed iron-based powder includes a pearlitic structure. 
     
     
         3 . A powder metal material as set forth in  claim 1  further including admixed molybdenum disulfide in an amount of about 0.1 to about 4.0% by weight of said powder metal material; admixed copper in an amount of about 1.0 to about 5.0% by weight of said powder metal material; and said powder metal material is free of phosphorous. 
     
     
         4 . A powder metal material as set forth in  claim 1 , wherein said admixed graphite includes particles having a U.S. standard sieve designation finer than 200 mesh; and said admixed graphite is present in an amount of about 0.25 to about 1.50% by weight of said powder metal mixture. 
     
     
         5 . A sintered powder metal article comprising:
 a powder metal material including pre-alloyed iron-based powder and admixed free graphite;   said pre-alloyed iron-based powder including carbon present in an amount of about 0.25 to about 1.50% by weight of said pre-alloyed iron-based powder.   
     
     
         6 . A sintered powder metal article as set forth in  claim 5 , wherein said pre-alloyed iron-based powder includes a pearlitic structure. 
     
     
         7 . A sintered powder metal article as set forth in  claim 5 , wherein said powder metal material further includes admixed molybdenum disulfide in an amount of about 0.1 to about 4.0% by weight of said powder metal material, admixed copper in an amount of about 1.0 to about 5.0% by weight of said powder metal material, and said powder metal material is free of phosphorous. 
     
     
         8 . A sintered powder metal article as set forth in  claim 5 , wherein said admixed graphite includes particles having a U.S. standard sieve designation finer than 200 mesh; and said admixed graphite is present in an amount of about 0.25 to about 1.50% by weight of the powder metal material.