Iron-based sintered sliding member and manufacturing method thereof

Abstract

An iron-based sintered sliding member that contains no free cementite in its structure and is excellent in tribological property such as friction and wear, and a method of manufacturing that iron-based sintered sliding member are provided. To iron powder as a main component, 3-20 mass % alloy powder, which comprises 4-6 mass % manganese, 3-5 mass % iron, and copper as a remaining component, and 1-5 mass % carbon powder are blended, and mixed to obtain powder mixture. Then, the powder mixture is filled in a mold and compacted to make a green compact of a desired shape. This green compact is sintered at a temperature of 1000-1100 degrees Celsius for 60 minutes in a heating furnace whose inside is adjusted to be a neutral or reducing atmosphere.

1 . An iron-based sintered sliding member, wherein:
 the iron-based sintered sliding member member is made from iron powder, copper-iron-manganese alloy powder, and carbon powder, and comprises 2.67-18.60 mass % copper component, 0.12-1.20 mass % manganese component, 1.0-5.0 mass % carbon component, and iron component as a remaining part;   structure of matrix of the iron-based sintered sliding member presents pearlite structure or structure in which pearlite partially coexists with ferrite; and   carbon and copper-iron-manganese alloy are dispersed in the structure of the matrix.   
     
     
         2 . An iron-based sintered sliding member of  claim 1 , wherein the copper-iron-manganese alloy precipitates dispersedly in net-like forms at grain boundary of the structure of the matrix. 
     
     
         3 . An iron-based sintered sliding member of  claim 1 , wherein: the structure of the matrix shows hardness of 350-450 in terms of micro Vickers hardness (HMV); the copper-iron-manganese alloy dispersed in the structure shows hardness of 100-120 in terms of micro Vickers hardness (HMV). 
     
     
         4 . An iron-based sintered sliding member of  claim 1 , wherein the carbon is natural graphite or artificial graphite. 
     
     
         5 . An iron-based sintered sliding member of  claim 1 , wherein the iron-based sintered sliding member contains 10-15 volume % lubricant oil. 
     
     
         6 . An iron-based sintered sliding member manufacturing method, comprising:
 blending 3-20 mass % alloy powder which comprises 4-6 mass % manganese, 3-5 mass % iron, and copper as a remaining part, and 1-5 mass % carbon powder to iron powder as a main component, and mixing the powders, to make powder mixture;   then, filling the powder mixture in a mold and compacting the powder mixture to obtain a green compact of a desired shape; and   sintering the green compact at a temperature of 1000-1100 degrees Celsius for 30-60 minutes in a heating furnace whose inside has been adjusted to be a neutral or reducing atmosphere.   
     
     
         7 . An iron-based sintered sliding member manufacturing method of  claim 6 , wherein natural graphite or artificial graphite is used as the carbon. 
     
     
         8 . An iron-based sintered sliding member manufacturing method of  claim 6 , wherein, after obtaining the iron-based sintered sliding member by sintering the green compact, the iron-based sintered sliding member is subjected to impregnation process so that lubricant oil is impregnated in proportion of 10-15 volume %. 
     
     
         9 . An iron-based sintered sliding member manufacturing method of  claim 7 , wherein, after obtaining the iron-based sintered sliding member by sintering the green compact, the iron-based sintered sliding member is subjected to impregnation process so that lubricant oil is impregnated in proportion of 10-15 volume %. 
     
     
         10 . An iron-based sintered sliding member of  claim 2 , wherein: the structure of the matrix shows hardness of 350-450 in terms of micro Vickers hardness (HMV); the copper-iron-manganese alloy dispersed in the structure shows hardness of 100-120 in terms of micro Vickers hardness (HMV). 
     
     
         11 . An iron-based sintered sliding member of  claim 10 , wherein the carbon is natural graphite or artificial graphite. 
     
     
         12 . An iron-based sintered sliding member of  claim 2 , wherein the carbon is natural graphite or artificial graphite. 
     
     
         13 . An iron-based sintered sliding member of  claim 3 , wherein the carbon is natural graphite or artificial graphite. 
     
     
         14 . An iron-based sintered sliding member of  claim 2 , wherein the iron-based sintered sliding member contains 10-15 volume % lubricant oil. 
     
     
         15 . An iron-based sintered sliding member of  claim 3 , wherein the iron-based sintered sliding member contains 10-15 volume % lubricant oil. 
     
     
         16 . An iron-based sintered sliding member of  claim 4 , wherein the iron-based sintered sliding member contains 10-15 volume % lubricant oil. 
     
     
         17 . An iron-based sintered sliding member of  claim 10 , wherein the iron-based sintered sliding member contains 10-15 volume % lubricant oil. 
     
     
         18 . An iron-based sintered sliding member of  claim 11 , wherein the iron-based sintered sliding member contains 10-15 volume % lubricant oil. 
     
     
         19 . An iron-based sintered sliding member of  claim 12 , wherein the iron-based sintered sliding member contains 10-15 volume % lubricant oil. 
     
     
         20 . An iron-based sintered sliding member of  claim 13 , wherein the iron-based sintered sliding member contains 10-15 volume % lubricant oil.