|
Zinc
is the material of choice for this die casting, based on mechanical
properties, electrical conductivity, dimensional accuracy, and
machinability.
|
Three types of
zinc
alloys can be considered for this application - |
ZAMAK
#3 |
ZAMAK
#5 |
Zinc
ZA-8 |
|
| Alloy
Properties |
Target |
Zamak
#3 |
Zamak
#5 |
Zinc
ZA-8 |
| Ultimate Tensile Strength
(ksi) |
>40 |
41 |
48 |
54 |
| Tensile Yield Strength (ksi) |
>30 |
32 |
39 |
41- 43 |
| Hardness
(BHN) |
>80 |
82 |
91 |
100-106 |
| Impact
Strength (ft-lb) |
>40 |
43 |
48 |
24-35 |
| Electrical Conductivity
(micro ohm inches) |
>25 |
27 |
26 |
27.7 |
| Dimensional
Accuracy ( 1= High, 5= Low) |
1 |
1 |
1 |
2 |
| Machinability
( 1= High, 5= Low) |
1 |
1 |
1 |
2 |
| Alloy
Cost ( $ / pound) |
Best
value |
$0.593 |
$0.603 |
$0.613 |
|
Alloy Data from the
NADCA Handbook: Product Specification Standards for Die Castings;
Alloy Costs = Market Price November 2004. |
|
Choose an alloy (Zamak
#3, Zamak #5, Zinc
ZA-8) for the
elbow housing, based on the property requirements and
specifications, as shown above. |
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11 |
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