Page 326 - Manufacturing Engineering and Technology - Kalpakjian, Serope : Schmid, Steven R.

Section 12.3 Casting Alloys 305

TABLE 2.4
I
Mechanical Properties of Gray Cast Irons
ASTM Ultimate tensile Compressive Elastic modulus Hardness
class strength (MPa) strength (MPa) (GPa) (HB)
20 152 572 66-97 156
25 179 669 79-102 174
30 214 752 90-113 210
35 252 855 100-119 212
40 293 965 110-138 235
50 362 1130 130-157 262
60 431 1293 141-162 302

TABLE I 2.5
Properties and Typical Applications of Nonferrous Cast Alloys

Ultimate Yield Elongation
tensile strength strength in 50 mm
Alloys (UNS) Condition (MPa) (MPa) (%) Typical applications
Aluminum alloys
195 (AO1950) Heat treated 220-280 110-220 8.5-2 Sand castings
319 (AO3190) Heat treated 185-250 125-180 2-1.5 Sand castings
356 (AO35 60) Heat treated 260 185 5 Permanent mold castings
Copper alloys
Red brass (C83600) Annealed 235 25 Pipe fittings, gears
Yellow brass (C86400) Annealed 275 25 Hardware, ornamental
Manganese bronze (C86100) Annealed 480 30 Propeller hubs, blades
Leaded tin bronze C925 00) Annealed 260 35 Gears, bearings, valves
(
Gun metal C905 00) Annealed 275 30 Pump parts, fittings
(
Nickel silver (C97600) Annealed 275 1 5 Marine parts, valves
Magnesium alloys
AZ9 1A F 230 3 Die castings
AZ6 3A T4 275 12 Sand and permanent
mold castings
AZ91 C T6 275 5 High-strength parts
EZ3 3A T5 160 3 Elevated-temperature parts
HK3 1A T6 2 10 8 Elevated-temperature parts
QE22A T6 275 4 Highest-strength parts

and brakes. Parts made of aluminum and magnesium alloys are known as light-metal
castings.

Magnesium-based Alloys. The lowest density of all commercial casting alloys are
those in the magnesium-based group. They have good corrosion resistance and
moderate strength, depending on the particular heat treatment used. Typical appli-
cations include automotive wheels, housings, and air-cooled engine blocks.

Copper-based Alloys. Although somewhat expensive, copper-based alloys have
the advantages of good electrical and thermal conductivity, corrosion resistance, and
nontoxicity, as well as wear properties suitable for bearing materials. A wide variety
of copper-based alloys is available, including brasses, aluminum bronzes, phosphor
bronzes, and tin bronzes.