Iron-based sintered alloy having excellent machinability
View Patent ↗This iron-based sintered alloy contains 0.05 to 3% by mass of calcium carbonate or 0.05 to 3% by mass of strontium carbonate. As a result, an iron-based sintered alloy having excellent machinability is obtained.
1. An iron-based sintered alloy having excellent machinability, consisting of 0.05 to 3% by mass of calcium carbonate, 15 to 27% by mass of Cr and 3 to 29% by mass of Ni, the balance being Fe and inevitable impurities.
2. An iron-based sintered alloy having excellent machinability, consisting of 0.05 to 3% by mass of calcium carbonate, 14 to 19% by mass of Cr and 2 to 8% by mass of Ni, the balance being Fe and inevitable impurities.
3. The iron-based sintered alloy having excellent machinability according to claim 1 , wherein the calcium carbonate is dispersed at grain boundaries in a in a matrix of the iron-based sintered alloy.
4. A method for preparing the iron-based sintered alloy having excellent machinability according to claim 1 , comprising the steps of:
compacting a raw powder mixture containing metal powders of Fe, Cr and Ni, and 0.05 to 3% by mass of a calcium carbonate powder to obtain a green compact, the calcium carbonate powder having an average particle size of 0.1 to 30 μm as a raw powder; and
sintering the resulting green compact in a nonoxidizing gas atmosphere.
5. The iron-based sintered alloy having excellent machinability according to claim 2 , wherein the calcium carbonate is dispersed at grain boundaries in a matrix of the iron-based sintered alloy.
6. A method for preparing the iron-based sintered alloy having excellent machinability according to claim 2 , comprising the steps of:
a raw powder mixture containing metal powders of Fe, Cr and Ni, and 0.05 to 3% by mass of a calcium carbonate powder to obtain a green compact, the calcium carbonate powder having an average particle size of 0.1 to 30 μm as a raw powder; and
sintering the resulting green compact in a nonoxidizing gas atmosphere.