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Silicon Carbide VS Aluminum Oxide?

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Editor:JKX Machinery Release date:2022-12-21 Views:1486

                            Today, let us talk something the following topic.

                               What is the difference between silicon carbide and aluminum oxide?


1.Different raw materials between aluminum oxide and silicon carbide

We name the aluminum oxide is brown corundum in the following words.


Brown corundum: commonly known as carbon corundum, is a brown artificial corundum formed by smelting reduced alumina, carbon materials and iron filings in an electric arc furnace. Therefore, it is called "brown corundum". Its main chemical composition is alumina, its content is 95.00%≤97.00%, and it contains a small amount of iron, silicon, titanium, etc. Brown corundum is the most basic abrasive, and it is widely used because of its good grinding performance, wide application range and low price.


Silicon carbide is also a rare mineral in nature - cyanite. Silicon carbide is also known as silicon carbon. Due to its small natural content, silicon carbide is mainly man-made. The usual method is to mix quartz sand with coke, use quartz sand and petroleum coke, add salt and sawdust, put it in an electric furnace, heat it to about 2000°C, and process various chemical treatments to obtain silicon carbide powder.


2. Different uses between brown corundum and silicon carbide

Brown corundum can be used in ceramics, resin high-consolidation abrasives, grinding, polishing, sandblasting, precision casting, etc., and can also be used to manufacture advanced refractory materials.

Silicon carbide has four main application areas, namely functional ceramics, advanced refractories, abrasives and metallurgical raw materials.


3. Different properties of brown corundum and silicon carbide

Brown fused alumina has the characteristics of high purity, good crystallinity, strong fluidity, low linear expansion coefficient, and corrosion resistance. It is only suitable for removing burrs on the surface of hardware parts such as stainless steel, carbon steel, and aluminum alloys.


There are two basic varieties of silicon carbide, black silicon carbide and green silicon carbide, which belong to α-SiC. (1) Black silicon carbide contains about 95% silicon carbide, and its toughness is higher than that of green silicon carbide. It is mainly used for processing low tensile strength materials such as glass, ceramics, stone, refractory materials, cast iron, and non-ferrous metals. (2) Green silicon carbide contains more than 97% SiC and has good self-sharpness. It is mainly used for precision grinding of hard alloy, titanium alloy, optical glass, honing sleeve and high-speed steel tool. In addition, there is cubic silicon carbide, which is a special process of yellow-green crystal. This abrasive tool is suitable for superfinishing of bearings, and the surface roughness can be processed from Ra32~0.16 micron to Ra0.04~0.02 micron.


4.Different costs of brown corundum and silicon carbide


Because of the scarcity of silicon carbide raw materials, the cost of silicon carbide-related abrasives will be 10%-15% more expensive than those made of brown corundum. This is also a concern of many users and buyers, so according to the characteristics of the product Testing and bulk purchase are particularly important, because we need to control some unnecessary costs during the grinding and polishing process.


For example, our following sponge sanding block


微信图片_20221221162408.jpg

It can be made of silicon carbide + sponge, or brown corundum + sponge. It can be easily distinguished from the color of the surface as shown in the picture below.

The black one on the left is a silicon carbide sponge, and the right is a brown corundum sponge.


In some ways of grit alone, 

the smaller the number is, the coarser the grit is , which is more suitable for rough grinding, such as deburring, rust removal, and surface oxide removal; 

the larger the number is, the finer the grit is ,which is more ideal for fine grinding, such as a mirror-like effect. (Of course, the mirror effect needs to be matched with other products, you can refer to our other article).


Coarse grit number: 60, 80

Medium grit number: 100, 120, 150, 180

Fine grit number: 220, 240, 280, 320, 400, 600


Price difference: For the following products, under the same grit conditions, silicon carbide is 0.1~0.3 RMB more expensive than brown corundum.

You can consult our professional customer service staff online “Ashley”for the specific price, and she will provide you with a reasonable price according to your packaging, quantity, and size requirements. Here is her contact way.

E-mail: jiukangxiang002@abrasives-depot.com

Whatsapp number:  https://wa.me/<8613179615576>


I believe you will love our product, because it works really well and is extremely cost-effective.

It follows that there are differences between brown corundum and silicon carbide in terms of processing technology, raw material itself, and price. 

When purchasing, you should choose the appropriate product according to your usage and the actual characteristics of the product. We are very glad to talk with you the new crafts.