Commercial brass powders are available in the simple brasses ranging from 95Cu-5Zn to 60Cu-40Zn and leaded versions of these brasses, and in modified brasses containing such elements as phosphorus, manganese and silicon. Nickel silver powders containing 64Cu-18Ni-18Zn and 64Cu-18Ni-16.5Zn-1.5Pb are also available on the commercial market. These powders are produced by atomizing alloy melts.

Optimum properties are attained by preheating to drive off lubricants and sintering in a cracked ammonia atmosphere. The P/M parts produced by such procedures have mechanical properties comparable with those of the corresponding cast alloys. Typical properties of representative brasses and nickel silvers are given in Table 4. These P/M alloys have moderate strength with good ductility.

Table 4. Typical Mechanical Properties of Brass and Nickel Silver P/M Compacts Pressed at 30 Tons/Sq. In. (414 MPa)

Nominal Composition Sintered Density Tensile Strength Elongation Rockwell
g/cm/cm3 ksi MPa % in 1 in. Hardness
90Cu-10Zn 8.1 30 207 20 H77
85Cu-15Zn 8.2 31.5 217 20 H82
70Cu-30Zn 8.1 38 262 21 H87
88.5Cu-10Zn-1.5Pb 8.4 30 207 25 H76
80Cu-18.5Zn-1.5Pb 8.2 34.5 238 31 H82
68.5Cu-30Zn-1.5Pb 7.7 34.6 239 29 H71
Nickel Silver
64Cu-18Ni-18Zn 7.9 34 234 12 B83
64Cu-18Ni-16.5Zn-1.5Pb 7.8 28 193 11 B84
Source: Data from New Jersey Zinc Company and U.S. Bronze Powders, Inc.

Next to bronze bearings, the brasses and nickel silvers are the most widely used materials for structural P/M parts. Examples of the many applications are hardware for latch bolts and cylinders for locks; shutter components for cameras; gears, cams and actuator bars in timing assemblies; small generator drive assemblies; and decorative trim and medallions.