P/M Copper Steels for Automotive Engineering Applications

Copper steels are used to fabricate high strength parts. The alloys are useful because they exhibit high strength, hardness and wear resistance. Copper alloy contents of 2-w/o are most popular. Higher copper content is alloyed to increase wear resistance. In the as-sintered condition, these alloys achieve ductility of less than 1%. Of alloys containing from 2-w/o to 10-w/o copper with 0.45 or 0.8-w/o combined carbon, specimens were compacted at 425 or 640 MPa, and sintered using a cycle commonly applied in a belt furnace. The alloys were found to have combined carbon content within controllable limits. Contamination was low. The tensile strength of the sintered copper steel was higher than that of typical values listed in Standard 35. Elongation for 2-w/o-copper/9-w/o-carbon copper steels was 3%. For 5-w/o-copper/9-w/o-carbon copper steels, elongation was 2%. Processing and cost to obtain these properties is discussed. Additional work now in progress will also be discussed.