Magnesium and aluminum are both light metals with similar properties. When comparing the density of these two elements, it’s important to note that magnesium is much lighter than aluminum. Magnesium has a density of 1.74 g/cm3 , while aluminum has a density of 2.70 g/cm3 . This means that although Magnesium and Aluminum have similarities in behavior, they have vastly different densities — making them useful in different applications.
Difference Between Aluminum and Magnesium:
1. Corrosion
Aluminum – Aluminum metal is corrosion resistant. Magnesium – Magnesium has a tendency to corrode, but very slowly.
2. Atomic number
The number of aluminum atoms is 13. The atomic number of magnesium is 12.
3. Cost-effectiveness
Aluminum alloys are less expensive. Its die casting cost is lower. Magnesium alloys are expensive. Die casting costs are quite high.
4. Biological effects
Aluminum has no significance in biological systems and there is no evidence for its role in any biochemical process. While living organisms do contain some amount of aluminum, there isn’t any scientific evidence for its requirement in the human body. Magnesium is important for both plants and animals. In plants, photosynthesis cannot take place without magnesium; in humans, magnesium assists in the work of various enzymes. Humans consume about 250-350 mg of magnesium per day. It is mainly stored in human bones.
5. Specific gravity
Aluminum has a specific gravity of 2.7. Magnesium has a specific gravity of 1.7.
6. Alloy properties
Aluminum alloys take longer to solidify and also provide longer die life. Aluminum is fairly stable, less expensive and does not bend easily under stress due to its strength. Magnesium alloys require less time to solidify. Magnesium is unstable, very expensive, and because of its softness, tends to bend under stress.
7. Cation
Al forms a +3 cation (a positively charged ion). Mg forms +2 cations.
8. Solubility
Aluminum is insoluble in water at room temperature. Magnesium is very soluble in water at room temperature and reacts with water.
9. Minerals
Bauxite, cryolite, beryl, garnet magnesite, marekite, ipsomite, dolomite, talc