AZ91D
- Corrosion resistance is achieved by enforcing very strict limits on three metallic impurities—iron, copper and nickel. These are limited to very low levels making it necessary to use primary magnesium in the production of this alloy
- As with all magnesium alloys, special precautions must be taken when machining
Working with AZ91D
- Designers of structural components must be aware of the creep limitations of magnesium alloys—generally with increasing temperature, the tensile strength, yield strength, and hardness of magnesium alloys decreases, while ductility increases
- In addition to environmental effects, there is a change in the metallurgical structure of magnesium over a period of time, and/or at elevated temperatures, that affects the mechanical properties
- This aging effect arises from the fact that the castings are produced under rapid solidification conditions which don’t allow the alloy to reach equilibrium (effectively, reactions between the alloy constituents have not been completed)
- Because creep is an important consideration in magnesium parts for elevated temperature use, stresses and times of operations should be known for both peak and normal conditions
Mechanical Properties
Physical Properties
Composition
| Magnesium | |
|---|---|
| % | AZ91D |
| Aluminum | 8.3-9.7 |
| Copper | 0.03 max |
| Magnesium | Bal. |
| Iron (max) | 0.005 |
| Lead (max) | |
| Cadmium (max) | |
| Tin (max) | |
| Nickel (max) | 0.002 |
| Zinc | 0.35-1.0 |
| Manganese | 0.15-0.5 |
| Silicon | 0.1 max |
| Other-Metallic | 0.02 |
| RoHS Compliant | ✓ |
