Method for producing sintered components from a sinterable material

Abstract

The present invention relates to sintered components and methods for preparing sintered components, which include the steps of introducing a sinterable material into a first mold, pressing the sinterable material to form a green compact; partially post-compressing the green compact in a second press mold, and, sintering the green compact. The density of the post-compressed green compact is greater than the density prior to compression.

1 . A method for preparing sinterable compositions comprising the steps of: 
 (a) introducing a sinterable material comprising 0.6 to 1.8 weight percent of at least one of a binder and a lubricant, based on the total amount of the sinterable material, into a first mold;    (b) pressing said sinterable material to form a green compact;    (c) at least partially post-compressing the green compact in a second press mold by uniaxial compression, such that the density of the post-compressed green compact is 2 to 40% greater than the density prior to post-compression.    
     
     
         2 . The method of  claim 1  further further comprising the step of sintering the green compact to form a sintered component.  
     
     
         3 . The method of  claim 1  wherein the green compact is substantially post-compressed.  
     
     
         4 . The method of  claim 1 , wherein said post-compression is performed at room temperature.  
     
     
         5 . The method of  claim 2 , further comprising the step of annealing the sintered green compact.  
     
     
         6 . The method of  claim 1 , wherein the green compact is compressed by vibrational compression.  
     
     
         7 . The method according to  claim 1 , further comprising the step of dewaxing the green compact prior to post-compression.  
     
     
         8 . The method of  claim 1 , further comprising the step of applying at least one lubricant to the second press mold.  
     
     
         9 . The method of  claim 1 , wherein sintering is performed under a nitrogen atmosphere with a dew point below at least −40° C.  
     
     
         10 . The method of  claim 1 , wherein said sinterable material comprises an iron-containing powder, an aluminum-containing powder, or a combination thereof.  
     
     
         11 . The method of  claim 1 , wherein said sinterable material comprises a ceramic-containing powder, a metal-containing powder, or a combination thereof.  
     
     
         12 . The method of  claim 1 , wherein the sinterable material comprises fibers having diameters between about 0.1 and 250 μm.  
     
     
         13 . The method of  claim 2 , wherein the sintered component is a gear wheel, a pump wheel, an oil pump wheel, a connecting rod, or a rotor set.  
     
     
         14 . The method according to  claim 1 , wherein the sinterable material comprises from 60 to 98.5 weight percent of an aluminum-based powder.  
     
     
         15 . The method of  claim 14  wherein the aluminum-based powder comprises: 
 aluminum; and    from 0.2 to 30 weight percent magnesium, from 0.2 to 40 weight percent silicon, from 0.2 to 15 weight percent copper, from 0.2 to 15 weight percent zinc, from 0.2 to 15 weight percent titanium, from 0.2 to 10 weight percent tin, from 0.2 to 5 weight percent manganese, from 0.2 to 10 weight percent nickel, or combinations thereof, based on the weight of the aluminum based powder.    
     
     
         16 . The method of  claim 14 , wherein the aluminum-based powder further comprises no more than 1 wt. % of arsenic, antimony, cobalt, beryllium, lead, boron, or combinations thereof, based on the weight of the aluminum-based powder.  
     
     
         17 . The method of  claim 1 , wherein the sinterable material further comprises from 0.8 to 40 weight percent of a first metal powder comprising molybdenum, tungsten, chromium, vanadium, zirconium, yttrium, or combinations thereof.  
     
     
         18 . The method of  claim 17 , wherein the first metal powder is a prealloy.  
     
     
         19 . The method of  claim 17 , wherein the sinterable material further comprises a second metal powder comprising copper, tin, zinc, lithium, magnesium, or combination thereof.  
     
     
         20 . The method of  claim 19 , wherein the second metal powder is a prealloy.  
     
     
         21 . The method according  claim 19 , wherein the ratio of the weight percent of the first metal powder to the weight percent of the second metal powder is from 1:8 to 15:1, based on the weight of the sinterable material.  
     
     
         22 . The method of  claim 14 , wherein the aluminum based powder is composed of: 
 aluminum; and    from 0.2 to 15 weight percent magnesium, from 0.2 to 16 weight percent silicon, from 0.2 to 10 weight percent copper, from 0.2 to 15 weight percent zinc, or a combination thereof, based on the weight of the aluminum-based powder.    
     
     
         23 . The method according to  claim 19 , wherein the second metal powder is composed of copper, tin, zinc, or a combination thereof.  
     
     
         24 . The method of  claim 1 , wherein the sinterable material further comprises from 0.2 to 5 weight percent of at least one lubricant, based on the total weight of the sinterable material.  
     
     
         25 . A sintered component prepared by the method of  claim 2.