Mixed powder for powder metallurgy, sintered body, and method for producing sintered body

Abstract

Disclosed is a mixed powder for powder metallurgy including: (a) an iron-based powder containing Si in an amount of 0 mass % to 0.2 mass % and Mn in an amount of 0 mass % to 0.4 mass %, with the balance being Fe and inevitable impurities; and (b) an alloyed steel powder containing Mo in an amount of 2.0 mass % to 21.0 mass %, Si in an amount of 0 mass % to 0.2 mass %, and Mn in an amount of 0 mass % to 0.4 mass %, with the balance being Fe and inevitable impurities, wherein a ratio of (b) the alloyed steel powder to a total of (a) the iron-based powder and (b) the alloyed steel powder is from 50 mass % to 90 mass %, and a ratio of Mo to the total of (a) the iron-based powder and (b) the alloyed steel powder is from 2.2 mass % to 6.2 mass %.

1 . A mixed powder for powder metallurgy comprising:
 (a) an iron-based powder containing Si in an amount of 0 mass % to 0.2 mass % and Mn in an amount of 0 mass % to 0.4 mass %, with the balance being Fe and inevitable impurities; and   (b) an alloyed steel powder containing Mo in an amount of 2.0 mass % to 21.0 mass %, Si in an amount of 0 mass % to 0.2 mass %, and Mn in an amount of 0 mass % to 0.4 mass %, with the balance being Fe and inevitable impurities, wherein   a ratio of (b) the alloyed steel powder to a total of (a) the iron-based powder and (b) the alloyed steel powder is from 50 mass % to 90 mass %, and   a ratio of Mo to the total of (a) the iron-based powder and (b) the alloyed steel powder is from 2.2 mass % to 6.2 mass %.   
     
     
         2 . The mixed powder for powder metallurgy according to  claim 1 , further comprising:
 (c) a Cu powder; and   (d) a graphite powder, wherein   a ratio of (c) the Cu powder to a total of (a) the iron-based powder, (b) the alloyed steel powder, (c) the Cu powder, and (d) the graphite powder is from 0.5 mass % to 4.0 mass %, and   a ratio of (d) the graphite powder to the total of (a) the iron-based powder, (b) the alloyed steel powder, (c) the Cu powder, and (d) the graphite powder is from 0.2 mass % to 1.0 mass %.   
     
     
         3 . The mixed powder for powder metallurgy according to  claim 2 , further comprising:
 (e) a lubricant, wherein   a ratio of (e) the lubricant to the total of (a) the iron-based powder, (b) the alloyed steel powder, (c) the Cu powder, and (d) the graphite powder is from 0.2 mass % to 1.5 mass %.   
     
     
         4 . A sintered body obtainable by forming and sintering the mixed powder for powder metallurgy as recited in  claim 1 . 
     
     
         5 . A method for producing a sintered body, comprising subjecting the mixed powder for powder metallurgy as recited in  claim 1  to forming and sintering to obtain a sintered body. 
     
     
         6 . A sintered body obtainable by forming and sintering the mixed powder for powder metallurgy as recited in  claim 2 . 
     
     
         7 . A sintered body obtainable by forming and sintering the mixed powder for powder metallurgy as recited in  claim 3 . 
     
     
         8 . A method for producing a sintered body, comprising subjecting the mixed powder for powder metallurgy as recited in  claim 2  to forming and sintering to obtain a sintered body. 
     
     
         9 . A method for producing a sintered body, comprising subjecting the mixed powder for powder metallurgy as recited in  claim 3  to forming and sintering to obtain a sintered body.