Aluminum Oxide Vs Silicon Carbide

Aluminum oxide and silicon carbide are both ceramic substances utilized as abrasives, with silicon carbide having harder, sharper grains but being less durable than its aluminum oxide counterpart. While both can be used on nonmetallic surfaces like wood or plastics, silicon carbide cannot withstand higher tensile strength metals such as steel.

Brown aluminum oxide is an exceptionally hard and long-wearing abrasive, capable of withstanding several blast cycles on softer materials such as rust and wood. White and pink varieties wear down more quickly but produce smoother finishes.


Aluminum oxide (also referred to as brown fused alumina or AL2O3) is one of the most frequently used synthetic abrasives, often called AL2O3 because of its composition as an alloy composed of aluminum and oxygen formed through fusion. Sorted according to mesh screen grit size for sorting purposes, aluminum oxide has the unique capability of grinding materials without damaging them, even at higher speeds, without being damaged itself in turn. Typical blasting abrasives with aluminum oxide included are for paint stripping, metal etching and refinishing applications as well as paint stripping, metal etching and refinishing tasks as AL2O3.

Silicon carbide features sharper and harder abrasive grains that make it suitable for etching hard nonmetallic objects, including some soft metals like brass. Furthermore, finer grits of silicon carbide make an excellent solution for refinishing wood flooring or cleaning glass edges.

Aluminum oxide offers the best balance among cutting speed, longevity and finish quality for softer woods and provides optimal finishing quality for most projects.

Wear Resistance

Aluminum oxide is a durable material that resists abrasion and corrosion, making it one of the most flexible synthetic abrasive grains available today.

Silicon Carbide is one of the hardest common abrasive grains outside of diamond. It measures at 9.5 on Mohs’ scale of hardness and can be used for grinding and polishing harder materials such as metals, glass and marble.

This highly versatile abrasive can be used in both suction- and direct-pressure blast systems for great effect, offering endless finishing opportunities. Use it alone or combine it with aluminum oxide abrasives to achieve different finishes.

To determine the wear resistance of alumina-silicon carbide nanocomposites, a ball-on-disk tribometer was utilized to monitor friction and wear at room temperature conditions. Our findings showed that composites with graphene exhibit twice the wear resistance compared to traditional ceramic alumina ceramics without graphene under loads of 10 N whereas their friction coefficient remained stable regardless.

Chemical Stability

Aluminum oxide differs from silicon carbide by being chemically stable and resistant to long-term heat exposure, as well as less vulnerable to acidic chemical degradation. Its chemical stability also makes aluminum oxide less susceptible to rusting than its silicon carbide counterpart.

Alumina can also be more effective at blasting hard metals than silicon carbide, though its smooth finish may not compare.

Silicon carbide is an extremely versatile and long-lasting grain type. You can use it both directly-pressure and suction-based systems, and over many blast cycles it is suitable for soft materials like glass, stone and marble as well as harder metals such as steel.

Silicon carbide can be an ideal material to work on tough, high-hardness materials if the appropriate grit type is selected. Metal is usually best-suited to silicon carbide’s sharp edges that wear down more quickly than their rounded alumina counterparts, while wood may pose challenges when cutting with it.

Thermal Conductivity

Silicon carbide and aluminum oxide abrasives play essential roles in various industrial processes. Each offers unique properties that make it suitable for different tasks and materials, and understanding the differences between them can help you select the most appropriate abrasives to meet your needs and achieve better results.

Silicon Carbide stands out among other materials due to its durability and resistance to high temperatures, making it a practical choice in industries like automotive and aerospace where high durability is key. Furthermore, its use in surface finishing and polishing extends product lifespan, decreasing premature wear that could lead to failure.

Aluminum oxide’s durability and chemical stability make it the ideal material for sanding low tensile metals such as those with lacquers or wood applications with lacquer finishes, making it suitable for wet-dry sanding applications as well. White or pink varieties tend to wear away faster while still leaving fine finishes than brown aluminum oxide varieties.

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