Comparing Zirconia with Aluminum Oxide Abrasives

There are two commonly used abrasive materials- aluminum oxide and zirconia alumina, which are used for a range of applications, including grinding and cutting, to finishing and polishing. Although they are both particularly used for eliminating material, they also have some differences. In this blog, we will cover all the details about Aluminum oxide and Zirconia alumina with their applications, pros and cons, and their differences. 

ALUMINUM OXIDE: WHAT IS IT?

One of the most preferred and heavily used ceramic materials is alumina oxide, sometimes known as alumina. Its amazing hardness and abrasive properties are what make it more recognized. Aluminum oxide serves as a vital abrasive in the material processing industry in a variety of applications, such as loose grains, sanding belts, and grinding wheels. What makes it so helpful is how well it removes waste from a range of surfaces, including wood, metals, and even some types of plastic.

Additionally, the accessibility of various grades of aluminum oxide, each having different friability, enables customized performance, ranging from aggressive stock removal to getting fine surface finishes. Aluminum oxides are highly economical and adaptable, still they are less durable and produce more heat compared to other abrasives in heavy-duty applications. 

ALUMINUM OXIDE ABRASIVE: APPLICATIONS

The key applications of aluminum oxide abrasives are as follows:

• Abrasives: Aluminum oxide is highly utilized as an abrasive because of its toughness, which is 9 on the Mohs scale. These are popularly used in grinding wheels, sandpaper, polishing compounds, and blasting media for surface preparation, material removal, and finishing. 
• Ceramics: Aluminum oxide is essential in the manufacturing of different ceramics such as tiles, sanitary ware, high-temperature furnace linings, and kiln furniture, due to its high melting point and thermal stability.
• Electrical Insulation: Aluminum oxide can also be used as an electrical insulator, spark plug insulator, electronic circuit substrates, and high-voltage componentry due to its exceptional electrical insulation qualities. 
• Biomedical Applications: It can also be used in medical implants, including hip and tooth replacements, and in Prosthetics and other medical equipment, due to its biocompatibility and wear resistance. 
• Catalysis and Chemical Processing: Aluminum oxide is also utilized as a catalyst support in a range of industrial chemical processes, such as petroleum refining and dehydration of alcohols. In addition, aluminum oxide can be used as an absorbent to eliminate water from gas streams. 
• Fillers: They are also used as a filler in plastics, coatings, paints, and rubber due to their white color and chemical inertness, to increase their mechanical properties, lifespan, and appearance. 
• Coatings: aluminum oxide can be used as a coating in the form of thin films, which can be applied as protective or decorative coatings on different materials. 

PROS

The aluminum oxide abrasive has the following advantages:

• Adaptability: Due to its adaptability, aluminum oxide is greatly preferred for a wide range of multipurpose applications
• Excellent hardness: aluminum oxide is hard enough to abrade a variety of common materials due to its Mohs hardness of 9.
• Highly Affordable: Aluminum oxide is highly cost-effective compared to other abrasives like zirconia and ceramic aluminum oxide. 
• Available in a wide range: Aluminum oxides are highly accessible, including grinding wheels, sanding belts, discs, and loose abrasive grains. 
• Ideal for wet and dry applications: unlike other abrasives, which are excellent at wet applications, aluminum oxide can be ideal for both wet and dry applications.

CONS

The following are the cons of Aluminum Oxide:

• Less durable: aluminum oxide tends to wear quickly when used aggressively or under high pressure. 
• Extreme heat generation: Compared to zirconia abrasives, aluminum oxide produces greater heat. This will result in the material’s discoloration or burning.
• Not suitable for very hard materials: although aluminum oxide is hard, it is not suitable for extremely hard materials like hardened tool steels or a few ceramics.
• Dull quickly: aluminum oxide becomes dull rapidly when working with specific materials like gummy or stringy materials. This will reduce its cutting efficiency. 
• Require frequent wheel dressing: When compared to other abrasives, aluminum oxide requires regular dressing in order to preserve its sharp cutting surface in grinding wheel applications. 

ZIRCONIA ALUMINA: WHAT IS IT?

Zirconia Alumina, also called zirconia-toughened alumina or alumina zirconia, is a type of composite ceramic material specifically designed for improving performance by mixing aluminum oxide with zirconium dioxide. This combination combines zirconia's "transformation toughening" mechanism—in which stress causes a change in zirconia's crystal structure, preventing fracture propagation—with the hardness and wear resistance of alumina to provide increased toughness and strength.

As zirconia alumina is highly durable and features a fracture-resistant quality compared to alumina, it is a more economical alternative than pure zirconia in difficult situations wherein mechanical strength, thermal shock, and wear resistance are required. 

ZIRCONIA ALUMINA: APPLICATIONS

The following are the applications of zirconia alumina:

• Cutting Tools: Zirconia alumina is widely utilized in various cutting tool inserts because of its hardness and toughness. It enables increased performance and durability when compared to traditional materials. 
• High-pressure Applications: Zirconia alumina is also ideal for deep well down-hole valves, ultra-high-pressure in pumping parts, and valve seals and seats in high-pressure tools due to its ability to endure high loads and fracture-resistance qualities. 
• Metal Forming: Zirconia alumina can also be used in metal forming operations, mainly for rollers and guides, because of its wear resistance qualities, and also they are capable of keeping dimensional accuracy under pressure. 
• Extrusion Dies: Zirconia alumina is also employed in metal extrusion dies because of its exceptional strength and ability to withstand deformation at high pressure and temperature.  
• Abrasive Applications: For removing material aggressively, particularly on hard metals such as steel, castings, granite, and stone, zirconia alumina is used in grinding wheels, coated abrasives, and blasting media.

PROS

The following are the pros of zirconia alumina:

• Excellent toughness: Zirconia alumina is a lot tougher compared to aluminum oxide. They are capable of enduring high grinding pressure and withstand breaking, which increases their lifespan.
• Aggressive cutting: zirconia alumina features an aggressive cutting action due to its self-sharpening and micro-fracturing ability.
• Generates less heat: zirconia alumina generates less heat when compared to aluminum oxide, which helps in minimizing the risk of burning the workpiece. 
• Durable: Zirconia alumina is highly durable and economical compared to aluminum oxide in the long run. 
• Suitable for tough materials: Zirconia alumina is perfectly suitable for grinding and finishing tough materials like stainless steel, tool steel, titanium, cast iron, and nickel alloys. 
• Self-sharpening ability: Zirconia alumina comes with self-sharpening abilities. Once the abrasive grains wear, they start showing new sharp cutting edges. This process is called friability. 
• Ideal for wet grinding: zirconia alumina is highly suitable for wet grinding. 

CONS

The following are the cons of zirconia alumina:

• High cost:  zirconia alumina’s manufacturing and purchasing cost is higher than that of aluminum oxide.
• Not suitable for soft materials: Zirconia alumina is not suitable for cutting softer materials, including aluminum, brass, or wood. 
• Not suitable for fine finish: A smooth or fine finish is not possible with zirconia alumina, as further steps with finer grits are required to achieve that finish. 

What to Choose Between Aluminum Oxide and Zirconia Alumina

Choosing between Aluminum oxide and Zirconia is totally based on the required applications and the user's priorities.

For Aluminum Oxide:

When choosing aluminum oxide, keep these points in mind:

• Budget: it is a crucial factor to consider while choosing between the two abrasives. Aluminum oxide is usually more economical than zirconia. 
• All-purpose abrasive: aluminum oxide is highly suitable for working with a number of materials, like softer metals, wood, and paint surfaces. 
• Ideal for finer finish: use finer grits of aluminum oxide, which is great at producing a smooth finish. 
• Suitable for low-pressure applications: Aluminum oxide can be performed without applying high pressure.
• Sensitive to heat: Although aluminum oxide can generate heat compared to zirconia, it is. The heat can be managed for some specific materials.
• Easily accessible: they are easily available in different shapes. 

For Zirconia Alumina:

When choosing zirconia lumina, keep these points in mind:

• Suitable for High stock removal: zirconia alumina is highly suitable for removing high stock due to its hardness and self-sharpening qualities. 
• Dealing with tough materials: They can easily work on tough materials like stainless steel, hard alloys, and cast iron. 
• High-pressure grinding: These abrasives can be used on projects requiring high-pressure grinding, as zirconia is known for its exceptional toughness, which enables it to endure high forces without fracturing. 
• Highly durable: When compared to aluminum oxide, zirconia alumina is more durable, particularly on difficult tasks. 
• Perfect for wet sanding: zirconia alumina is perfectly suitable for wet sanding.