Alumina is the most commonly used advanced ceramic material. It is widely used in manufacturing engineering and household appliances. Alumina is a cost-effective ceramic material with some exceptional properties.
The most important properties of alumina are extreme hardness, high melting point, high density, high thermal conductivity, excellent insulation capacity, and inertness.
This article will help you learn all these alumina properties in detail. Let’s begin.
What is Alumina?
Let’s quickly look over what alumina is before revealing its properties. It will help you understand the alumina properties better.
Alumina is a popular ceramic material known as aluminum oxide (Al2O3) or alkoxide.
The raw materials of alumina are ruby and sapphire which are available in nature. This raw alumina is processed in a system called the Bayer process.
Then it is used in various industries as a ceramic element to manufacture different items.
What Are The Important Properties of Alumina?
Aluminum oxide or alumina has several special properties making it a widely used ceramic material. The following are the most important alumna properties.
1.High Melting Point: Ceramic alumina has a melting point of around 2072℃ (degrees Celsius). It can tolerate extreme temperatures for this high melting point.
A high melting point is the heat required to melt material from solid-state to liquid. Usually, any material with a melting temperature above 700 degrees centigrade is considered a high melting point.
For this reason, industrial engineering alumina ceramic is widely used in furnaces and kilns.
2.Density: Alumina has a high density of around 3.9 g/cm3.
The density of a material is defined as its mass in grams divided by its volume in centimeter cubes. Hence, the unit of density is gram/cubic centimeter or g/cm3. It represents the density of a material is inversely proportional to its volume.
Alumina ceramic is a fine particle with no hollow space in its structure, no holo space means a higher density. So it is used as an element to manufacture abrasive equipment.
3.Hardness: Ceramic alumina is the second hardest material after diamond with a Mohs scale of 9. The Mohs scale is a hardness measurement unit ranging from 1 to 10. The unit name is taken from the German mineralogist Friedrich Mohs.
However, hardness is the ability of a material to resist deformation. The industrial ceramic alumina can withstand any scratch and dent.
You can create scratches on the alumina ceramic components using the diamond only. No other materials can scrap it.
4.Compressive Strength: Alumina has a compressive strength of 3000 MPa(Mega Pascal). Megapascal is the unit of measuring pressure mostly used in science and engineering.
One MPa(megapascal) = One million pascals.
Compressive strength means the stress-taking capacity of a material. It is the most essential mechanical property for structural hard materials.
Alumina can resist breaking down under high compression states for high compressive strength.
5.Corrosion resistance: Alumina is highly resistant to corrosion and wear. Corrosion resistance is the ability of a material to stand against deterioration and chemical breakdown in a corrosive environment.
Corrosion is damage that usually occurs due to oxidation and chemical reactions. When selecting a material to manufacture corrosion-resistant products, you must choose with high corrosion resistance.
Hence, aluminum oxide is used to manufacture pump bodies, pump impellers, thread guards, dosimeters, etc.
6.Chemical Resistance: Al2O3(alumina) is resistant to chemical reactions. It does not act in chemical reactions even in highly reactive chemical environments.
Chemical resistance is defined as the ability of a material to withstand taking part in any chemical reaction. Al2O3 does not make chemical reactions even in contact with highly reactive acids, bases, and alkalis.
Al2O3 is a popular material for the healthcare, aerospace, and automotive industries for this property.
7.Electrical Resistance: Ceramic alumina has a high electrical resistance of around 1×10^14 ohm centimeter(Ω-cm). Conversely, it has very low electrical conductivity at high temperatures and frequencies. It can hinder the electricity flow and ensure electrical safety.
Alumina can also prevent energy loss for this resistive character. Alumina ceramic components have numerous applications in electrical and electronic fields for this reason.
Alumina ceramic plates are the essential elements of transformers, power lines, and switchgear which are the vital equipment of power generation and distribution systems.
Another popular use of alumina is in electronic circuit boards and substrates to create separation between the conductive elements.
It also has applications in producing spark plugs, heating elements, microwave ovens, and radar systems.
8.Dielectric Strength: Alumina has a high dielectric strength of 400 AC-KV/mm. AC and KV stand for alternating current kilovolts. Dielectric strength is defined as the maximum voltage on the material before breaking down divided by its thickness in millimeters.
It is the measurement of the electrical strength of any insulating substance. The higher the dielectric strength of a material the higher its electrical insulation capacity.
FAQs
What Are the Physical Properties of Alumina?
The physical properties of alumina are the appearance, color, grain size and shape, purity, and hardness.
Is Alumina Ceramic?
Yes, alumina is a popular ceramic.
How to Define Alumina?
Alumina is a crystalline solid material consisting of different rocks and clays. It is one of the most impactful ceramic materials used to manufacture semiconductors, electronic substrates, automobile parts, etc.
The chemical composition of alumina is two aluminum and three oxygen atoms. Hence the formula is Al2O3.
What are the Mechanical Properties of Alumina?
The mechanical properties of alumina are mechanical strength, hardness, compressive strength, corrosion resistance, ductility, elasticity, and wear resistance.
What is the significance of alumina?
Ceramic alumina is also known as an advanced industrial ceramic material. It has a huge impact on modern industrial and engineering equipment and machinery manufacturing. It is an environmentally friendly and low-cost ceramic element.
Alumina is the key element of electrical circuit bases, sensors, transformers, switchgear, laser tubes, thermocouple tubes, ballistic armor, bulletproof glass, etc.
What Are The Electrical Properties of Alumina?
The electrical properties of alumina refer to the high resistivity, high dielectric strength, and low conductivity.
What Are The Chemical Properties of Alumina?
Inertness, chemical resistivity, and amphotericity are the basic chemical properties of alumina.
Bottom Line On The Important Properties of Alumina:
Knowledge about the important properties of alumina will help you to shine in your professional fields. Learning different alumina properties is the basis of its application as an engineering ceramic element.
This skill will guide you through the way to manufacture and use premium quality products with ceramic alumina.
We hope you enjoyed reading the article. Thank you.