Lubricant for hot forging applications

Abstract

A substantially lead-free lubricant for use in hot forging of metals, especially forging of aluminum and aluminum alloy components. The lubricant comprises one or more oils, graphite, and one or more phosphorus-based additives. Additional additives, such as metallic lubricants and dispersants may also be included. The lubricant does not burn when subjected to temperatures in excess of 300° C.

We claim: 
     
         1 . A hot forging lubricant comprising:
 a) about 30-99 wt % of one or more phosphate esters;   b) about 1 to about 70% of one or more oils different from a);   c) about 1 to about 30 weight percent graphite;   d) a metal containing fatty acid derivative; and   e) a dispersant;   
       wherein said hot forging lubricant is substantially lead-free and, when subjected to forging temperatures in excess of 300° C., said hot forging lubricant does not burn. 
     
     
         2 . The lubricant of  claim 1 , wherein the phosphate ester is present in a range of about 30 to about 80 weight percent of the lubricant; the one or more oils is present in a range of about 15 to about 40 weight percent of the lubricant; and the graphite is present in a range of about 1 to about 20 weight percent of the lubricant. 
     
     
         3 . The lubricant of  claim 1 , wherein the one or more oils are selected from the group consisting of mineral oil, vegetable oil, animal oil, synthetic oil, semi-synthetic oil and mixtures thereof. 
     
     
         4 . The lubricant of  claim 1 , wherein the graphite is selected from the group consisting of coarse, fine, milled, unmilled, natural, synthetic or mixtures thereof. 
     
     
         5 . The lubricant of  claim 1 , further comprising one or more metallic lubricating additives. 
     
     
         6 . The lubricant of  claim 1 , wherein the composition further comprises an additive selected from the group consisting of phosphate, phosphate amine, ammonium phosphate and mixtures thereof. 
     
     
         7 . The lubricant of  claim 2 , wherein the metal containing fatty acid derivative comprises one or more metals selected from the group consisting of bismuth, zinc, tin, aluminum or any alloys thereof. 
     
     
         8 . The lubricant of  claim 1 , wherein the phosphate ester is present in a range of about 30 to about 80 weight percent of the lubricant. 
     
     
         9 . The lubricant of  claim 1 , wherein the one or more oils is present in a range of about 15 to about 40 weight percent of the lubricant. 
     
     
         10 . The lubricant of  claim 9 , wherein the one or more oils are selected from the group consisting of mineral oil, vegetable oil, animal oil and mixtures thereof. 
     
     
         11 . The lubricant of  claim 3 , wherein the mineral oil is selected from naphthenic, aliphatic, paraffinic or steam cylinder oil; the vegetable oil is selected from sunflower oil, olive oil or rapeseed oil, and the synthetic oil is selected from polyalphaolefins and silicone oil. 
     
     
         12 . The lubricant of  claim 1 , wherein the graphite is present in a range of about 3 to about 20 weight percent of the lubricant. 
     
     
         13 . The lubricant of  claim 11 , wherein the graphite has a particle size distribution with about 90% of particles below 15 microns in size. 
     
     
         14 . The lubricant of  claim 1 , further comprising one or more selected from the group consisting of rheology modifiers, biocides, anticorrosives, extreme pressure additives, antifoam agents, wetting agents, metal soaps. 
     
     
         15 . A hot forging lubricant comprising:
 a.) 73% of at least one phosphate ester;   b.) 15% of a vegetable and/or animal oil;   c.) 4.4% of fine graphite;   d.) 3.2% of a mineral oil;   e.) 3.2% of a metal containing fatty acid derivative; and   f.) 0.2% of a dispersant.   
     
     
         16 . The lubricant of  claim 15 , wherein the mineral oil is selected from naphthenic, aliphatic, paraffinic or steam cylinder oil; and the vegetable oil is selected from sunflower oil, olive oil or rapeseed oil. 
     
     
         17 . A hot forging lubricant consisting of:
 a.) phosphate ester;   b.) vegetable and/or animal oil   c.) fine graphite   d.) mineral oil   e.) metal containing fatty acid derivative   f.) dispersant; and   g.) optionally additional ingredients selected from rheology modifiers, biocides, anticorrosives, extreme pressure additives, antifoam agents, wetting agents and mixtures thereof;   
       wherein the hot forging lubricant does not burn at temperatures in a range of about 300° C. to about 600° C. 
     
     
         18 . The lubricant of  claim 17 , wherein the phosphate ester is present in a range of about 30 to about 80 weight percent of the lubricant; the vegetable and/or animal oil is present in a range of about 15 to about 40 weight percent of the lubricant; and the graphite is present in a range of about 1 to about 20 weight percent of the lubricant.