Powder composition

Abstract

The present invention concerns a metal powder composition for the powder metal industry, wherein the metal powder is selected from the group consisting of an atomised iron-based powder or a sponge iron powder, and a lubricant composition comprising glyceryl stearate.

1 . A metal powder composition, wherein the metal powder is selected from the group consisting of an atomised iron-based powder or a sponge iron powder, and a lubricant comprising glyceryl stearate.  
     
     
         2 . A metal powder composition according to  claim 1 , wherein the glyceryl stearate is a mono-, di- or tristearate or a mixture thereof.  
     
     
         3 . A metal powder composition according to  claim 1  or  2 , wherein the metal powder composition includes 0.1-2.0% by weight of the lubricant.  
     
     
         4 . A metal powder composition according to any of the preceding claims, wherein the lubricant includes 5-95% by weight of the glyceryl stearate and 95−5% by weight of at least one lubricant selected from the group consisting of non-metallic fatty acid compounds and a metal salts of fatty acids.  
     
     
         5 . A metal powder composition according to  claim 4 , wherein the fatty acid compound is ethylene bisstearamide.  
     
     
         6 . A metal powder composition according to  claim 5 , wherein the lubricant is a present as a molten and subsequently micronised powder of glyceryl stearate and ethylene bisstearamide.  
     
     
         7 . A metal powder composition according to any of the preceding claims, wherein the iron-based powder is an essentially pure iron powder, a pre-alloyed or a diffusion alloyed powder.  
     
     
         8 . A metal powder composition according to  claim 7 , wherein the alloying element(s) for the pre-alloyed or diffusion alloyed powder are selected from the group consisting of copper, molybdenum, chromium, manganese, nickel, phosphorus and carbon in the form of graphite.  
     
     
         9 . A metal powder composition according to  claim 7 , wherein an essentially pure iron powder is admixed with an alloying element selected from the group consisting of copper, molybdenum, chromium, manganese, nickel, phosphorus and carbon in the form of graphite.  
     
     
         10 . A metal powder composition according to any of the preceding claims, wherein the metal powder also includes one or more additives selected from the group consisting of binders, processing aids and hard phases.  
     
     
         11 . A metal powder composition wherein the powder particles are surrounded by a coating including glyceryl stearate.  
     
     
         12 . Lubricant composition comprising 5-95% by weight of a glyceryl stearate and 95−5% by weight of at least one non-metallic fatty acid compound and/or a metal salt of a fatty acid.  
     
     
         13 . Lubricant composition according to  claim 10  wherein the non-metallic fatty acid compound is selected from the group consisting of ethylene bisstearamide, stearic acid and oleic acid.  
     
     
         14 . Lubricant composition according to  claim 10  wherein the metal salt of the fatty acid is selected from the group consisting of zinc stearate, calcium stearate and lithium stearate.  
     
     
         15 . Lubricant composition according to any one of the claims  10 - 13  in the form of a molten and subsequently micronised powder.