Mixed powder for iron-based powder metallurgy, method for producing same, sintered body produced using same, and method for producing sintered body

Abstract

The mixed powder for iron-based powder metallurgy of the present invention comprises an iron-based powder and a CaS raw material powder containing one or more selected from the group consisting of calcium sulfate anhydrite III, calcium sulfate anhydrite II, calcium sulfate dihydrate, calcium sulfide, and calcium sulfate hemihydrate. The CaS raw material powder is coated with at least one selected from a lubricant and a binder.

1 . A mixed powder for iron-based powder metallurgy, the mixed powder comprising an iron-based powder and a CaS raw material powder comprising at least one selected from the group consisting of calcium sulfate anhydrite III, calcium sulfate anhydrite II, calcium sulfate dihydrate, calcium sulfide, and calcium sulfate hemihydrate, wherein the CaS raw material powder is coated with at least one of a lubricant and a binder. 
     
     
         2 . The mixed powder for iron-based powder metallurgy according to  claim 1 , further comprising at least one ternary oxide selected from the group consisting of a Ca—Al—Si oxide and a Ca—Mg—Si oxide. 
     
     
         3 . The mixed powder for iron-based powder metallurgy according to  claim 2 , comprising the at least one ternary oxide and the CaS raw material powder such that a weight ratio of the at least one ternary oxide and CaS after sintering is 3:7 to 9:1. 
     
     
         4 . The mixed powder for iron-based powder metallurgy according to  claim 1 , comprising the CaS raw material powder such that a weight ratio of CaS after sintering is 0.01 wt % or more to 0.1 wt % or less. 
     
     
         5 . The mixed powder for iron-based powder metallurgy according to  claim 1 , wherein the CaS raw material powder has a volume-average particle size of 0.1 μm or more to 60 μm or less. 
     
     
         6 . A sintered body prepared by sintering the mixed powder according to  claim 1 . 
     
     
         7 . A method for producing a mixed powder for iron-based powder metallurgy, the method comprising:
 coating a CaS raw material powder, which comprises at least one selected from the group consisting of calcium sulfate anhydrite III, calcium sulfate anhydrite II, calcium sulfate dihydrate, calcium sulfide, and calcium sulfate hemihydrate, with at least one of a lubricant and a binder, to obtain a coated CaS raw material powder; and   mixing the coated CaS raw material powder with an iron-based powder, to obtain a mixed powder.   
     
     
         8 . A method for producing a sintered body, the method comprising sintering a mixed powder prepared by the method according to  claim 7  to obtain a sintered body, wherein the sintered body comprises CaS at a weight ratio of 0.01 wt % or more to 0.1 wt % or less.