Binder-lubricants for ferrous powder metallurgy

Abstract

A binder-lubricant for metallurgical powder compositions for powder metallurgy (P/M) applications having a melting point between 50 and 100° C. and comprising glyceryl esters of fatty acids. Addition of such binder-lubricant has improved resistance to dusting, and has improved green density for compacting temperature between 50 and 100° C.

1 . A method of producing a compacted powder composition, comprising: 
 a) adding about 0.01 wt. % to about 3 wt. %, based on the total weight of the composition of a binder-lubricant to an iron-based powder, said binder-lubricant consisting essentially of one or more glyceryl esters of fatty acids and having a melting point between 50 and 100° C. and;    b) compacting the dry metallurgical powder composition at a temperature in the range of 50 to 100° C.    
   
   
       2 . The method of  claim 1 , wherein from about 0.05 wt. % to about 1.5 wt. % of the binder-lubricant is added in step a).  
   
   
       3 . The method of  claim 1 , wherein the iron-based powder contains up to about 15 wt. % of one or more alloying elements.  
   
   
       4 . The method of  claim 4 , wherein the alloying elements are selected from the group consisting of: elemental copper, nickel, molybdenum, manganese, phosphorus, and metallurgical carbon.  
   
   
       5 . The method-of  claim 1  further comprising adding an additional lubricant to the powder metallurgical composition prior to compacting in step b).  
   
   
       6 . The method of  claim 5 , wherein the additional lubricant is a non-metallic fatty acid compound, polyolefinic waxes, or combination thereof  
   
   
       7 . The method of  claim 6 , wherein non-metallic fatty acid compound is selected from the group consisting of: ethylene bis-stearamide, stearic acid, oleic acid.  
   
   
       8 . The method of  claim 6 , comprising 5-95 wt. % of binder-lubricant and 95-5 wt. % of additional lubricant.  
   
   
       9 . The method of  claim 6 ,.comprising 30-95 wt. % of binder-lubricant and 70-5 wt. % of additional lubricant.  
   
   
       10 . The method of  claim 1  further comprising adding another binder to the powder metallurgical composition prior to compacting in step b).  
   
   
       11 . The composition of  claim 1 , wherein the glyceryl esters of fatty acids are selected from the group consisting of: mono-esters, di-esters, tri-esters of glycerol, and mixtures thereof.  
   
   
       12 . The method of  claim 1 , wherein the binder-lubricant comprises glyceryl esters of fatty acids having a C4-40 alkyl moiety that can be saturated or unsaturated, linear or branched, and substituted or unsubstituted.  
   
   
       13 . The method of  claim 1  wherein the iron-based powder has a maximum particle size less than about 600 microns.  
   
   
       14 . A method of producing a metal component, the method comprising sintering the compacted powder composition of  claim 1 .  
   
   
       15 . A compacted powder composition, comprising about 0.01 wt. % to about 3 wt. %, based on the total weight of the composition of a binder-lubricant to an iron-based powder, said binder-lubricant consisting essentially of one or more glyceryl esters of fatty acids and having a melting point between 50 and 100° C.  
   
   
       16 . The compacted powder composition of  claim 15 , comprising from about 0.05 wt. % to about 1.5 wt. % of the binder-lubricant.  
   
   
       17 . The compacted powder composition of  claim 15 , wherein the iron-based powder contains up to about 15 wt. % of one or more alloying elements.  
   
   
       18 . The compacted powder composition of  claim 17 , wherein the alloying elements are selected from the group consisting of: elemental copper, nickel, molybdenum, manganese, phosphorus, and metallurgical carbon.  
   
   
       19 . The compacted powder composition of  claim 15 , further comprising an additional lubricant.  
   
   
       20 . The compacted powder composition of  claim 19 , wherein the additional lubricant is non-metallic fatty acid compound, polyolefinic waxes, or combination thereof.  
   
   
       21 . The compacted powder composition of  claim 20 , wherein the non-metallic fatty acid compound is selected from the group consisting-of: ethylene bis-stearamide, stearic acid, oleic acid.  
   
   
       22 . The compacted powder composition of  claim 19 , comprising 5 -95 wt. % of the binder-lubricant and 95-5 wt. % of additional lubricant.  
   
   
       23 . The compacted powder composition of  claim 19 , comprising 30-95 wt. % of the binder-lubricant and 70-5 wt. % of additional lubricant.  
   
   
       24 . The compacted powder composition of  claim 15  further comprising an additional binder.  
   
   
       25 . The compacted powder composition of  claim 15 , wherein the binder-lubricant comprises glyceryl esters of fatty acids having a C4-40 alkyl moiety that can be saturated or unsaturated, linear or branched, and substituted or unsubstituted.  
   
   
       26 . The compacted powder composition of  claim 15 , wherein the iron-based powder has a maximum particle size less than about 600 microns.