
Overview
ZA alloys were initially developed for gravity casting. Their mechanical
properties compete directly with bronze, cast iron and aluminum using sand,
permanent mold and plaster mold casting methods. Beginning in the late 1950's
and continuing into the 1970's, Noranda, New Jersey Zinc Co. Ltd., St. Joe
Mineral Co. and ILZRO contributed to development of the ZA alloy group. Zinc
and Aluminum are the major alloy constituents, along with other minor additions
of magnesium and copper. The numbers associated with the name represent the
amount of aluminum in the alloy (i.e. ZA8 has 8% aluminum). Distinguishing
features of ZA alloys include high as-cast strength, excellent bearing
properties, as well as low energy (melting) requirements.
Eastern Alloys manufactures the entire ZA alloy group. There are many different
gravity-casting processes such as permanent mold, graphite permanent mold,
plaster, and sand. In general these processes are used for low to medium volume
requirements, and also as a prototyping technique.
Top
Mechanical Properties
| Ultimate Tensile Strength:
psi x 103 (MPa) |
38 (263) |
32-37 (221-255)
|
40-46 (276-317)
|
45-50 (310-345) |
58-64 (400-441) |
45-47 (310-324) |
| Yield Strength - 0.2% Offset:
psi x 103 (MPa) |
29 (200) |
30 (206) |
31 (214) |
39 (269) |
54 (372) |
37 (255) |
| Elongation: %
in 2" |
1-2 |
1-2 |
1-3
|
1-3 |
3-6 |
8-11 |
| Shear Strength:
psi x 103 (MPa) |
- |
35 (241) |
37 (255) |
- |
42 (290) |
33 (228) |
| Hardness: Brinell |
85 |
85-90 |
89-105 |
89-105 |
110-120 |
90-110 |
| Impact Strength:
ft-lb (J) |
156 (20) |
- |
193 (25) |
- |
353 (47) |
433 (58) |
| Fatigue Strength Rotary Bend - 5x108
cycles: psi x 103 (MPa) |
- |
7.5 (52) |
15 (103) |
- |
25 (172) |
15 (103) |
Compressive Yield Strength 0.1%
Offset:
psi x 103 (MPa) |
29 (199)
|
31 (214) |
33(227) |
34 (234)
|
48 (331)
|
37 (255)
|
Modulus of Elasticity - psi x 106
(MPa x 103) |
12.4 (85.5)
|
12.47 (85.5) |
12.07 (82.7) |
12.07 (82.7) |
11.37 (77.9) |
11.37 (77.9) |
| Poisson's Ratio |
0.29 |
0.29 |
0.30 |
0.30 |
0.32 |
0.32 |
Top
Physical Properties
| Density: lb/cu
in (g/cm3) |
0.227 (6.3)
|
0.227 (6.3)
|
0.218 (6.0) |
0.218 (6.0) |
0.181 (5.0)
|
0.181 (5.0)
|
| Melting Range:
°F (°C) |
707-759 (375-404) |
707-759 (375-404) |
710-810 (377-432)
|
710-810 (377-432)
|
708-903 (376-484)
|
708-903 (376-484)
|
| Electrical Conductivity:
%IACS |
27.7 |
27.7 |
28.3 |
28.3 |
29.7 |
29.7 |
| Thermal Conductivity:
BTU/ft/hr/°F (W/m/hr/°C) |
66.3 (114.7) |
66.3 (114.7) |
67.1 (116.1) |
67.1 (116.1) |
72.5 (125.5)
|
72.5 (125.5)
|
Coefficient of Thermal Expansion:
68-212°F µin/in/°F (100-200°C µm/mm/°C) |
12.9 (23.3)
|
12.9 (23.3)
|
13.4 (24.2)
|
13.4 (24.2)
|
14.4 (26.0)
|
14.4 (26.0)
|
| Specific Heat:
BTU/lb/°F (J/kg/°C) |
.104 (435)
|
.104 (435)
|
.107 (448)
|
.107 (448)
|
.125 (534)
|
.125 (534)
|
| Pattern of Die Shrinkage:
in/in |
1/8 in/ft |
5/32 in/ft
|
1/8 in/ft
|
5/32 in/ft |
5/32 in/ft
|
5/32 in/ft
|
Top
Compositions
| Al |
8.2-8.8 |
8.0-8.8 |
10.8-11.5 |
10.5-11.5 |
25.5-28.0 |
25.0-28.0 |
| Mg |
.020-.030 |
.015-.030 |
.020-.030 |
.015-.030 |
.012-.020 |
.010-.020 |
| Cu |
0.8-1.3 |
.8-1.3 |
0.5-1.2 |
0.5-1.2 |
2.0-2.5 |
2.0- 2.5 |
| Fe (max) |
.065 |
.075 |
.065 |
.075 |
.072 |
.075 |
| Pb (max) |
.005 |
.006 |
.005 |
.006 |
.005 |
.006 |
| Cd (max) |
.005 |
.006 |
.005 |
.006 |
.005 |
.006 |
| Sn (max) |
.002 |
.003 |
.002 |
.003 |
.002 |
.003 |
Ni
(other)x10
|
- |
- |
- |
- |
- |
- |
| Zn |
Bal. |
Bal. |
Bal. |
Bal. |
Bal. |
Bal. |
Color Code
ASTM B908 |
Blue |
Orange |
Purple |
| |
|
|
Top
Shapes and Sizes
Top
Eastern Alloys, Inc. is a member of the London Metal Exchange, or LME, ILZRO,
Interzinc, NADCA, and DDC.