Patent attributes
The subject invention reveals a process for making hardened powder metal parts which comprises compacting a powder metal composition into a green preformed metal part and subsequently sintering said green metal part to produce the powder metal part at an elevated temperature and subsequently cooling the sintered part at a rate which is sufficient to insure the formation of a substantial amount of martensite, wherein the powder metal composition is comprised of copper powder, a nickel powder and a base iron powder wherein said composition contains from about 1 weight percent to about 5 weight percent of the total sum of said copper powder and said nickel powder and wherein the ratio of the nickel powder to the copper powder is within the range of 1:1 to 9:1, and wherein the balance of said composition constitutes iron.
