Lubricant for powder metallurgy

Abstract

A lubricant for use in a powder mixture is disclosed. This lubricant contains carnauba wax and at least one plant- or animal-based fat. A powder mixture using this lubricant can be used to compact green parts have higher densities and helps to improve the life of the tools compacting the powder.

1 . A lubricant for powder metallurgy comprising:
 carnauba wax; and   at least one plant- or animal-based fat.   
     
     
         2 . A lubricant in accordance with  claim 1  wherein the fat is a vegetable fat. 
     
     
         3 . A lubricant in accordance with  claim 1  wherein the at least one fat contains at least 6% oleic acid by weight. 
     
     
         4 . A lubricant in accordance with  claim 1  wherein the fat has an iodine value of at least 40. 
     
     
         5 . A lubricant in accordance with  claim 1  wherein the fat has a saponification value of at least 150 mg KOH/g. 
     
     
         6 . A lubricant in accordance with  claim 1  wherein the at least one fat is solid or liquid. 
     
     
         7 . A lubricant in accordance with  claim 1  were the lubricant contains at least one fat that is solid at a temperature of 20° C. 
     
     
         8 . A lubricant in accordance with  claim 1  wherein the fat contains at least one fat that is solid at a temperature of 20° C. and at least one fat that is liquid at a temperature of 20° C. 
     
     
         9 . A lubricant in accordance with  claim 1  wherein the at least one fat is selected from a group consisting of rapeseed oil, coconut oil, soya oil, linseed oil, palm oil or palm fat, sunflower oil, walnut oil, hazelnut oil, olive oil, castor oil, tallow, fish oil, and derivatives of the aforementioned substances. 
     
     
         10 . A lubricant in accordance with  claim 1  wherein the lubricant comprising at least 50% carnauba wax by weight and at least 10% of a vegetable fat by weight that is solid at a temperature of 20° C., wherein the weight percent are calculated based on the total quantity of the lubricant. 
     
     
         11 . A lubricant in accordance with  claim 1  wherein the lubricant comprises at least 5% carnauba wax by weight, at least 20% by weight of a first vegetable fat and at least 40% by weight of a second vegetable fat that is liquid at a temperature of 20° C., wherein the weight percent are calculated based on the total quantity of the lubricant. 
     
     
         12 . A method of using of the lubricant of  claim 1  as an additive to a sinterable powder mixture or as a sizing lubricant in powder metallurgy. 
     
     
         13 . A mixture for the manufacture of sintered parts comprising at least one lubricant in accordance with  claim 1  and at least one metallic material. 
     
     
         14 . A mixture in accordance with  claim 13  wherein the mixture contains 0.1% to 2.0% lubricant by weight, calculated on the basis of the total weight of the mixture.