Silicon Carbide Abrasive Vs. Aluminum Oxide Abrasive

Among various types of abrasives, silicon carbide and aluminum oxide are the most often utilized. The application where you require them should be kept in mind when deciding between these two options. Sanding products such as sandpaper sheets, sanding belts, and sanding pads are made of silicon carbide and aluminum oxide and differ in key ways that make one preferable for a given application.

They vary in terms of pricing, adaptability, and performance levels. One of these is usually present in most woodworking and metalworking applications where material surface sanding is necessary. In this article, you'll discover the distinctions between silicon carbide and aluminum oxide abrasives so that you may choose wisely for your tasks.

Silicon Carbide Abrasives

Compared to aluminum oxide, silicon carbide has sharper and harder abrasive grains. It is not as resilient as abrasives made of aluminum oxide, though. This is due to its brittleness and narrower shape, gradually deteriorating with use. Cutting glass, plastic, and medium-density fiberboard with light pressure is quite simple, thanks to the razor-sharp silicon carbide grains. Metals and hardwoods cannot be cut with the same ease, though.

Since silicon carbide is more brittle than aluminum oxide, it is a great material for working on rough surfaces. You can apply it to wet sanding as well. Compared to ordinary (black) silicon carbide, friable silicon carbide is harder and purer but is also more brittle. While the green kind is better for polishing the surfaces of materials, the standard (black) silicon carbide is used to grind non-ferrous metals, ceramics, and hard non-metals. You can polish metal, remove rust, refinish wood floors, clean glass edges, and deburr metal.

The silicon carbide sanding belt is a frequently used silicon carbide abrasive for harder materials like wood finishes, stone, metal, and paint and softer ones like glass, rubber, and plastic. With the best grain coverage, the belts have a closed coat. This enables you to polish the surface with sealants or lacquers or apply the grain to a hard substance. And last, materials like cast iron, aluminum, and cemented carbide are the ones that are most often used in silicon carbide grinding wheels and sanding discs.

If you want to know the difference between various other abrasive grains, follow the link to ceramic vs aluminum oxide vs zirconia abrasive grains.

Aluminum Oxide Abrasives

The most widely used abrasive grain in metal and woodworking industries is aluminum oxide.

This is because it performs better than silicon carbide on various surfaces, such as metal, painted surfaces, bare wood, and painted surfaces. Aluminum oxide is superior to most other choices, whether you're working on wood or metals. 

Three shades of aluminum oxide abrasives are brown, white, and pink. The most typical type of aluminum oxide is brown.

• White aluminum oxide:  White aluminum oxide is found in coarse to fine textures; because it generates less heat, it works best on wood and lacquers. Aluminum oxide in white and pink deteriorates more quickly but leaves a smoother, finer surface. Compared to brown aluminum oxide, they resemble silicon carbide more closely.
• Pink aluminum oxide: Pink aluminum oxide is available in coarse through fine textures. It applies to softer woods.
• Brown aluminum oxide: The third and most lasting variety of aluminum oxide is brown, whose grains degrade far more slowly than pink and white varieties. You can sand extremely tough materials like metals, drywall, fiberglass, wood, and painted surfaces. Compared to smoother pink or white aluminum oxides, it works better and is less expensive.

Silicon Carbide Vs. Aluminum Oxide Abrasives

Use silicon carbide instead of aluminum oxide if the material you're working with is non-metallic or has poor tensile strength. Belts made of aluminum oxide can only be utilized in dry processes. You can use aluminum oxide on materials with high tensile strengths if you intend to utilize metal grinding tools. This comprises high tensile bronze, aluminum alloys, and stainless steel.

Remember that successfully pairing silicon carbide and aluminum will result in a significantly finer abrasive effect on the same sanding project. In applications involving woodworking, this method is typical. Starting with aluminum oxide abrasives for rough sanding, you move on to silicon carbide for the last stages. Doing this may create a flawless surface finish without using up all of your sandpaper.

CONCLUSION

Aluminum oxide and silicon carbide are two ceramic substances utilized as abrasives. Although silicon carbide is less durable than aluminum oxide, it is sharper and more rigid than aluminum oxide grains. Aluminum oxide works best on materials with high tensile strengths, while silicon carbide is best for non-metallic or low tensile strength materials. You can combine both to create an abrasive cut that is smoother and finer while preserving the abrasives.