Black Silicon Carbide Polishing

Black silicon carbide (Carborundum) is an extremely hard and angular abrasive that’s commonly used for blast tumbling applications. Being much less friable than brown fused alumina, black silicon carbide can be repeatedly utilized within blast tumbling applications without much risk to product integrity.

Polishing composition can be purchased either as an all-in-one package containing liquid carrier, abrasive particles and an oxidizing agent or in multiple containers that need to be combined shortly before use.

Abrasive

Black silicon carbide powder is a widely popular choice when it comes to sanding or polishing applications, especially when applied as an abrasive grain. Boasting an impressive hardness rating of 9.1 on the Mohs scale, black silicon carbide is considered one of the hardest common abrasive grains and used across numerous industries such as aerospace and automotive where precision lapping and finishing of various components require it. Furthermore, ceramics and glass applications such as metallurgical applications utilizing its properties also utilize this material in etch or polish surfaces or ceramic applications when used as an abrasive grain.

Copper alloys are also often found in abrasives like sandpaper and grinding wheels due to their extreme toughness, which helps withstand high-pressure blasting without breaking. Furthermore, its chemical and heat resistance makes it suitable for resisting chemical reactions as well. Copper can also be found in nonferrous metals used for nonferrous metal casting and semiconductor production due to its superior thermal conductivity and wear resistance properties.

This abrasive is frequently found on sanding belts, discs and sponges for hand and power sanding applications. It’s particularly ideal for wet sanding stone and marble surfaces as well as deburring metal and glass objects before derusting to refinish wood flooring between finishing coats. At coarser grit levels it may even be used to remove dents or other imperfections in raw or unfinished wood flooring.

Aluminum oxide may outlive it when it comes to some applications, but silicon abrasives remain highly durable and can withstand multiple blast cycles before needing replacement. They etch well, providing an excellent surface preparation for finishing coatings; additionally they’re frequently used in other fields such as sandblasting, wiresawing silicon & quartz materials as well as non-slip applications and non-bonded coated abrasives bonded/coated applications as well.

This type of abrasive is produced by reacting and pyrolyzing vaporized polysiloxanes in one heating step to form silicon carbide, which is then ground to produce its grains. According to application, different shapes and sizes may be produced; dry form is available or it can be dispersed in liquid carriers (soil solvent, viscosifier or emulsifier).

Polishing Composition

Silicon carbide is an exceptionally hard material used for cutting metals, glass and ceramics. More durable than aluminum oxide abrasives but less hard than diamonds or boron carbide, silicon carbide makes an excellent material to use when grinding applications are required – often found in coated bonded and coated non-bonded abrasive products like sandpaper and grinding wheels. Abrasive blasting employs special machinery to propel an abrasive stream against surfaces to remove rust, prepare surfaces for painting or remove old finishes from products.

Polishing composition used for silicon carbide polishing comprises a liquid carrier, an abrasive suspended in that liquid carrier and an oxidizing agent. The abrasive may be either ground or manufactured, and should have particle sizes from approximately 0.3 microns up to approximately 100 microns for best results. Silicon carbide and silica-based materials are both great choices as sources for polishing agents; hydrogen peroxide or ammonium cerium nitrate could also work effectively as an oxidizing agent.

To maximize abrasive performance, the polishing composition ideally includes chelating or complexing agents as an enhancement component. Such chemical additives help increase removal rate from substrate layer being polished or remove trace metal contaminants from abrasives. Ideal candidates for such agents include carbonyl compounds (e.g. acetylacetonates), simple carboxylates (such as acetates lactates and gallic acid) di-, tri- and polycarboxylates (such as citrates succinates tartrates malates and edetates such as dipotassium EDTA).

Polishing composition can either be mixed before use or mixed on-site during chemical-mechanical polishing processes. Preferably, colloidally stable polishing compositions should be chosen; that means the abrasive particles remain suspended in their liquid carrier without falling off into suspension. A buffering agent such as formic acid, acetic acid or other organic acids may also be added as needed to adjust pH accordingly for specific applications; in addition, an appropriate pH adjustor could also be included as part of its contents.

Oxidizing Agent

Silicon carbide, often abbreviated SiC, is an exceptionally strong and resilient abrasive used for wet applications such as sandblasting. Produced by melting and sintering crystalline material into grains with razor sharp edges, SiC is commonly found used by manufacturers. SiC can be found naturally in certain meteorites, corundum deposits and kimberlite. However, most SiC sold in the US is made synthetically. An abrasive is often utilized in abrasive blasting, which uses specialized machinery to project media at high speeds across hard surfaces. This process can be used to remove rust from products for painting or deburring metal as well as remove old finishes from materials’ surfaces.

In polishing compositions, an oxidizing agent helps keep abrasives suspended in their liquid carriers to ensure that their use in abrading does not quickly wear down their strength against SiC substrates during abrading operations and cause mechanical damage to SiC surfaces. Furthermore, this prevents any reaction between SiC substrate and abrasives during abrading processes that might otherwise lead to chemical reaction that could damage SiC surfaces in other ways.

Chemical-mechanical polishing (CMP) is widely employed within the semiconductor industry to achieve a highly polished surface on silicon devices, such as flat panel displays, integrated circuits and memory or rigid disks. A pad saturated with polishing slurry containing an abrasive and an oxidizing agent is then applied directly onto each silicon device; once applied it can then be buffed away to remove an oxidized silicon layer as well as gouges and crates that remain on its surface.

Abrasives come in two main colors – black or green. Black abrasive can be used for grinding non-ferrous metals, ceramics and hard non-metals while green abrasive is more friable and used wet sanding; additionally it can also be used on wood, marble and glass for wet sanding, deburring metal parts and smoothing glass edges. People typically combine them both together using aluminum oxide for rough sanding then silicon carbide for final refinishing steps before finishing surfaces are finished using silicon carbide.

Cheating or Complexing Agent

Silicon carbide can be more challenging to polish than aluminum oxide due to its sharper, harder abrasive grains. Therefore, stronger polishing agents like EDTA or NTA are needed in order to prevent its oxidization by trapping it in chemical complexes and trapping it within them.

High-pressure polishing systems use special abrasives that shorten the time required to finish substrate surfaces, providing significant time savings over conventional abrasive systems that require multiple steps for similar results. Ideal substrates include flat panel displays, memory or rigid disks, metals, interlayer dielectric devices (ILD) devices and semiconductors. Furthermore, this polishing method offers greater defect removal compared to traditional methods.