Common Castings Considerations
- Greater Flexibility In Designing Complex Shapes.
- Dissipate Stress That Cause Fatigue Cracking.
- Blending Shapes That Adhere To Clearance Issues.
- Move Fabrication / Weld Joints To Low- Stress Areas Or Eliminate Fab Joints!
- Provide Durability Resistance To Impact Loads.
- Weight Enhancement
Most of the common alloys can be cast using expendable molds of some kind. But their use in reusable mold depends on their melting points. A reusable mold process can't be used if the melting point of the alloy is higher.
Each alloy has its own strengths and weaknesses with regard to cost, reliability, dimensions held, metallurgical quality, volume production and competitive situation. Things to be considered, while selecting an alloy, are as follows:
- Cost
- Strength
- Hot strength
- Hardness
- Density (weight limitations)
- Bearing qualities (galling resistance)
- Machinability
- Weldability
- Brazability
- Brazability
- Abrasion resistance
- Corrosion resistance
- Oxidation resistance
- Fatigue properties
- Resistance to crack propagation
- Electrical conductivity
- Magnetic properties
- Thermal conductivity
Followings are the two tables that may be useful in Selecting a Casting Alloy :
Followings are the two tables that may be useful in Selecting a Casting Alloy :
Alloy Fitness for Reusable Mold Processes
(Ordered lowest to highest by melting point)
(Ordered lowest to highest by melting point)
| Base | Maximum Strength (1000s psi) | Reusable Mold |
| Zinc | 61 | Yes |
| Aluminum | 60 | Some alloys |
| Magnesium | 40 | Yes |
| Copper | 150 | Some alloys |
| Cast iron | 60 | Some alloys |
| Cobalt | 110 | No |
| Nickel | 130 | No |
| Stainless steel | 200 | No |
| Tool steel | 220 | No |
| Maraging steel | 240 | No |
| Low alloy steel | 220 | No |
| Carbon steel | 150 | No |
| Titanium | 160 | No |
Comparison Chart For Various Alloys
| Aluminum Alloys |
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| Magnesium Alloys |
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| Beryllium Alloys |
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| Copper Alloys |
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| Nickel Alloys |
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| Titanium Alloys |
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| Refractory Metals |
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