Currently, the advantages of metal magnesium is often very easy to accept for many of individuals, but there are still a considerable number of people who does not have a definite knowledge of its characteristics, despite some misconceptions, it is necessary to clarify these misunderstandings. The common misconception of such metal contains 6 points as shown below:
1. Magnesium is flammable metal.
This misunderstanding is due to many pyrotechnic products using magnesium powder, thus creating this impression.In fact, magnesium ingots, magnesium die casting, magnesium profiles, all of them will not burn unless the temperature rises to the melting point (651 Degree Celsius) . Accuracyately speaking, easy burning materials made of such metal are magnesium powder, magnesium wire and magnesium foil.
2. Magnesium metal is erodible.
Through theoretical and experimental research, People found that impurity elements involved in Mg metal such as iron, nickel and copper, as well as the proportion of iron and manganese had great corrosion resistance for magnesium alloy, later the United States developed a high purity die- cast alloy AZ91D. AZ91D increases more than 100 times than the original AZ91A / AZ91B and AZ91C for corrosion resistance. While in aspect of salt spray corrosion resistance capabilities, most of die-cast magnesium alloys have surpassed aluminum alloy A380. In fact, Mg metal is similar to aluminum in many respects. For example, before surface coating, both of metals have to have a surface pretreatment, to ensure affinity. Surface preparation are generally chemically treated, such treatment also improves the ability of anti-corrosion.
3. Metallic Magnesium is a scarce metal.
This is clearly wrong, actually magnesium (Mg) account for 2.5% of the earth's crust, second only to aluminum, iron, calcium, potassium. The Mg element content follows after elemental chlorine and sodium elements in seawater. So we can say that magnesium element is inexpensive.
4. Magnesium is not easy-forming metal.
Many of people think that the crystal structure of magnesium alloy is close-packed hexagonal at room temperature, there is only one movable slip systems in the crystal, concluding that magnesium alloy forming difficult. This is in fact a one-sided understood, in fact, the magnesium alloy in the compressive stress has very good ductility at high temperatures, it may be by extrusion, forging and rolling forming. Moreover, the plastic deformation is a forming method of its alloy, magnesium alloy can also be shaped by casting, and die casting properties of such alloy is better than most of aluminum alloys.
5. Magnesium is an expensive metal.
Previously, an important factor in restricting the application of magnesium alloy is that it is much more expensive than aluminum alloy. At present, it is generally the same level as aluminum alloy in the domestic and international market. Worthy of note is that, we can not only consider its price by weight, but also consider their density as well as the characteristics of magnesium alloys in the manufacturing, all of which will make the impact of its cost. Comprehensive comparison, it can not be believed that metallic magnesium is expensive metal.
6. What is the accurate concept of high purity magnesium?
What is the purity magnesium? What is the exceptionally pure magnesium? for the vast majority of people, it may not be quite clear, in fact, there is no essential difference for both of international standards: high-purity magnesium and extra virgin magnesium. Currently they are usually ranked in the form of the magnesium content of 99.95%, 99.5%, 99% and referred to as pure magnesium for which generally meet the standard of 99% magnesium ingot.