Properties and Applications of Magnesium

Magnesium resembles aluminum metal. However, it has unique properties that make it ideal for different industries. It is the 3rd most abundant element present (dissolved) in seawater. Moreover, its presence on the earth’s crust is also noticeable. Understanding the properties and applications of magnesium is crucial.

 

Magnesium’s properties make it unique for particular purposes. For example, its lightweight and low density makes it ideal for aerospace. Rust resistance is another characteristic that makes it suitable for the manufacturing process. This topic needs a detailed explanation, so let’s dive in and discuss its salient features.

 

Overview of Magnesium

Magnesium is a silver-colored metal that is very lightweight and easy to ductile. Its rust resistance and electrical conductivity make it stand out. Many industries use it on a large scale to manufacture different parts. The automobile and aerospace industries are at the top of the list.

 

As I said, magnesium is generally of silver color. But you may also see it in a dull gray patina. Magnesium is a reactive metal, and it reacts with oxygen readability. Due to this reaction, magnesium oxide is formed. Due to this magnesium oxide layer, the color of magnesium changes from silver to a dull gray patina.

 

The discovery of magnesium started in 1808. British chemist Sir Humphry Davy first produced pure magnesium. His production process used a magnesium sulfate and mercury mixture. During the process, he passed electrical current through this mixture. Later this mixture underwent a heating process.

 

He later filtered out the mercury and separated the magnesium from the mixture. Many other scientists also tried their luck and found significant advancement. However, industrial-scale production of magnesium and processing of magnesium alloys started in the 1930s. Its usage across different industries is increasing due to many suitable properties.

 

Properties of Aluminum

 

Interestingly, some people consider magnesium an aluminum replacement. However, it has many unique features that give it different value propositions. Moreover, people use magnesium with varying alloy metals to achieve desired outcomes. Let’s dive deep and discuss magnesium’s properties.

 

1- Low Density & Highly Flammable

As I mentioned, magnesium has a low density of 1.738 g/cm 3. Because of this low density, it is lightweight compared to aluminum and other metals. Therefore, manufacturers use it in the aerospace industry and automobiles. 

 

Their low weight improves the fuel consumption of aircraft and automobiles. Magnesium is highly flammable and produces an intense, bright white flame. The temperature of these flames is too high, making it ideal for emergency flares. Keep in mind that this metal is also very reactive in the air.

 

2- Corrosion Resistance

Magnesium is excellent at rustproofing because it readily reacts with oxygen. This reaction forms magnesium oxide, which protects the magnesium from further corrosion. Magnesium is used to make products exposed to moisture.

 

Let me give you one disclaimer. Magnesium metal does not resist rust if it remains in the harshest conditions. The layer of oxide can be depleted. In such cases, corrosion will attack quickly due to magnesium’s reactive nature. So, it would be best to be wise while using magnesium-made products. They are decent only in mild moisture conditions.

 

3- Excellent Electrical & Thermal conductivity

Magnesium metal is used to make many electronic components. Due to its optimal electrical conductivity, it is prevalent in laptops and computers. It is suitable for electrical conductance, but don’t compare it with copper. Even its performance is under par as compared to aluminum.

 

Therefore, you won’t see magnesium wires to be used for electrical systems. Copper wires are commonly preferred due to better electrical conductance. Let’s discuss magnesium’s thermal conductivity. It dissipates heat and transfers it between parts. So, it’s good for home utensils and cooking tools.

 

4- Alloys Formation & Excellent Castability

Imagine this: you need a part with high strength but low weight. How would you achieve this? If you need strength, you must keep your weight up, right? However, engineers aim to keep the weight low and the strength of the parts up in aerospace. Magnesium alloys are handy for this.

 

You can use another element, such as zinc, to make zinc or aluminum and make an alloy. This alloy element will be firm but lightweight. Different types of magnesium alloys have varying properties. This enables the engineer to achieve the desired properties using these alloys.

 

Castability is another popular property of magnesium metal. You can create various shapes and designs using this metal. The reason is that it is soft and easy to form. Moreover, it is not brittle, so machining it is straightforward. Many manufacturers use magnesium to make complex parts of automobile engines.

 

5- Reactivity, Melting and Boiling Points

First, magnesium metal is very reactive. As I said earlier, its reacting capability makes it excellently corrosion-resistant. Magnesium reacts with oxygen to form a magnesium oxide layer. This layer is very beneficial in protecting magnesium against rust and corrosion. In the section above, I mentioned that magnesium has excellent castability.

 

The reason is that it has a low melting point of 650 degrees Celsius. The manufacturers efficiently provide this temperature and change the shape of magnesium. It is safe to say that magnesium melting can be achieved easily. Let’s now talk about the boiling point associated with thermal stability.

 

Magnesium’s boiling point is very high (1090 degrees Celsius). This means it is very strong and thermally stable. It does not degrade when heated gently or remains on harsh summer days. The products made with this material perform decently in outdoor use.

 

6- Soft, Ductile & High Strength-To-Weight Ratio

Magnesium is not very hard or brittle, so it is highly machinable. Manufacturers can put it under different machines and get the desired shape. Moreover, it has high strength. Surprisingly, its density is very low, around 1.738 g/cm 3, but its strength is excellent.

 

Magnesium is around 75% and 33% lighter than steel and aluminum. However, the excellent strength-to-weight ratio makes it stand out. For example, the AZ91D magnesium alloy is very strong. It has a tensile strength of 230 MPa (33,000 psi). This is why engineers use magnesium in places where low weight and high strength are needed.

 

Applications of Raw Magnesium 

 

Primary magnesium is used to make magnesium alloys. It’s also used in steelmaking desulfurization, rare earth alloys, and metal reduction. A top use of raw magnesium is to make corrosion-resistant parts. Many steel mills use magnesium for desulfurization. 

 

The desulfurization effect of using magnesium particles is better than calcium carbide. Magnesium sacrificial anodes effectively prevent metal corrosion. They are used for cathodic protection. These sacrificial anodes are widely used in:

 

• Evaporators
• Gas stations
• Water heaters
• Heat exchangers
• Boilers & Smelters
• Petroleum pipelines
• Natural gas pipelines and storage tanks

 

Application of Magnesium Alloy

Magnesium alloy has many valuable features that make it a hot-selling material. Those include:

 

• Machinability
• Corrosion resistance
• Shock absorption
• Dimensional stability
• Impact resistance

 

These characteristics make magnesium alloys applicable in a wide range of fields. These industries are making our lives sustainable. Some prominent sectors include transportation, electronics, medical, and military. Moreover, the trend of magnesium usage is only increasing. Let’s dive deeper and explore some typical applications.

 

1- Use of Magnesium in Transportation

(1) Airplane

Since the 20th century, magnesium alloys have been used in aerospace. Many plane parts use magnesium alloy. The question is, why? Magnesium alloys are lightweight. So, plane parts made with this material weigh less. General aviation magnesium alloys are mainly plates and extrusions. 

 

Remember, the casting of magnesium alloys is used less in the aviation industry. Magnesium alloys make civil and military aircraft parts, propellers, gearboxes, and brackets. Some rockets, missiles, and satellite parts also use them. As magnesium alloy production technology improves, so will its performance. Its use will grow, too.

 

(2) Car

Magnesium alloys are majorly used in the automobile industry. They are used to make dashboards, seat brackets, gearbox housings, and steering systems. These alloys also contribute to engine blocks, frames, etc.

 

Using magnesium alloys to make auto parts can significantly reduce a car’s weight. This cuts fuel use and exhaust emissions. It also improves part integration and design flexibility. A 10% decrease in a vehicle’s weight can boost fuel efficiency by 5.5%.

 

Two ways to make cars lighter are to optimize the design and use lightweight materials. Three ideal materials for manufacturing are aluminum alloys, plastics, and magnesium alloys. Plastics are resin-based composites.

 

Magnesium alloy die-casting is the lightest die-casting alloy. It is a very competitive, lightweight material for automobiles. Many magnesium alloy parts are made to replace plastic, aluminum, and even steel parts. As technology advances, magnesium alloys will have more uses in cars.

 

2- Telecommunication

Digital technology has advanced rapidly in the electronic information industry. The market now demands more integrated, light, thin, and compact products. In the past, engineering pigments were the primary materials used.

 

However, their strength is questionable, especially when compared with magnesium alloys. Remember, these alloys offer excellent thin-wall casting performance. Their die-casting parts can have a wall thickness of 0.6 to 1.0 mm. 

 

Magnesium alloy maintains strength, stiffness, and crash resistance despite being thin. This makes it ideal for ultra-thin, ultra-light, and miniaturized products. Engineering pigments cannot match these qualities.

 

Magnesium alloy is currently used in various electronic products. It won’t be wrong that the electronic industry heavily relies on these alloys. Those products include cameras, camcorders, digital cameras, notebook computers, mobile phones, and televisions. The need for lightweight, thin, compact 3C products is driving the use of magnesium alloys.

 

(1) Notebook Computer

The use of magnesium alloy for the notebook’s chassis or housing is due to its many advantages. Its shockproof performance improves the reliable operation of computer components. Anti-electromagnetic interference and electromagnetic shielding are also critical. Their performance ensures the computer’s information security.

 

(2) Cell Phone

The mobile phone uses magnesium alloy. It prevents shock, wear, and electromagnetic waves. It can also meet light, thin, short, and minor requirements. The mobile phone with a magnesium alloy case has improved electromagnetic compatibility. This cuts electromagnetic wave loss in communication and reduces their harm to humans. In 2005, 400 million mobile phones were made worldwide. About 10% to 11% of them used magnesium alloy casings.

 

(3) Digital Camera

The skeleton of the SLR camera is usually made of magnesium alloys. The structure of professional digital SLR cameras also relies on these alloys. They make them durable and give them a good feel. So, even if the camera falls, it won’t break or get scratched. Their body and casing become invincible to shocks.

 

3- Medical Treatment

Magnesium was first introduced in the medical field as an orthopedic biomaterial. Due to its many features, magnesium implants are beautiful. In the early days, medical implants used stainless steel, titanium, and cobalt-chromium alloys.

 

Their advantage was their good corrosion resistance. They were able to maintain the body’s structural stability for a long time. However, the patient had to suffer after their implantation. These materials also could not fuse with the body. So, harmful metal ions are eluted, causing allergies. A second operation is needed to remove them after healing.

 

So, biodegradable medical metals are the future of implant materials. Magnesium alloys, with a 1.7 g/cm³ density, are close to human bone, which is 1.75 g/cm³. They have unique advantages that make them stand out. For example, magnesium alloys are easy to process and can biodegrade. This is an excellent replacement for stainless steel and titanium.

 

Magnesium is a vital macro metal for the human body. It wouldn’t be wrong to say that our body cannot sustain itself without it. The elastic modulus of magnesium alloy is about 45 GPa, which is close to that of human bone (10-40 GPa). It can relieve or avoid the “stress shielding effect.”

 

The magnesium ions the alloy releases can promote bone cell growth and healing. Also, magnesium alloys outperform other degradable implants, like polylactic acid and calcium phosphate. So, they have value in clinical applications, like cardiovascular stents.

 

4- Military Industry

In the start, I mentioned that aluminum alloys are very strong and durable. So, their usage in the military industry is increasing. These alloys in military equipment can improve structural parts. Not only this, but they can also reduce weight and increase weapon accuracy. Magnesium alloys also meet the material requirements for aerospace and other high-tech fields.

 

They are excellent for noise absorption, shock absorption, and radiation protection. These alloys also greatly improve plane aerodynamics by reducing their weight. Thus, magnesium alloys are often used to manufacture plane parts. The popular uses of these alloys are in wall panels, brackets, cylinder head boxes, and pistons.

 

Do you know bunker brackets, mortar bases, and missiles? They are integral pieces of military defense systems. They are all made of magnesium alloys. An in-depth study of magnesium alloys will reveal more opportunities and uses. As their properties improve, magnesium alloys will be used more in weapons.

 

5- Other Application

Magnesium alloys are also widely used in daily routines. For example, they are commonly used to make motorcycles and bicycles. Bicycles are new uses of magnesium alloys. They are mainly used for bicycle frames. Magnesium alloy has many advantages.

It is light, fast, and comfortable. It also has a mouth that allows the pipe diameter to be smaller, the pipe wall to be thinner, and the frame to be more robust. The magnesium alloy folding bicycle frame weighs only 1.4 lbs. Another example is a wheelchair, a key piece of rehabilitation equipment. Commercially available wheelchairs can be divided into three types

 

• Standard (consist of aluminum, titanium alloy)
• Lightweight
• Ultralightweight

 

The AZ31 magnesium alloy makes the wheelchair frame and parts. You might be confused as to why this particular alloy is used. It is lightweight and reduces the weight of wheelchairs by about 15%. So, such wheelchairs made from AZ31 alloy are both super lightweight and flexible. Remember, magnesium alloys are used in marine equipment, such as:

 

• Underwater weapons
• Seawater batteries
• Diving suits
• Sacrificial anodes
• Timing devices

 

They play a crucial role in the shipbuilding industry and marine engineering. They are used in many applications and are essential in our daily lives.

 

Conclusion

It won’t be wrong to say that magnesium makes our lives possible. Many industries use it to create different parts and components. What makes it popular among manufacturers is its user-friendly features. Is there any field of life where magnesium has no role?

 

I bet there is no such field in our world. Magnesium has numerous features, the most prominent of which are rustproofing and lightweight. Due to this, this material is used in many different industries. In this guide, we have discussed all the applications of magnesium and its alloys.