please click here:

https://www.dragon-abrasives.com/silicon-carbide.html

Introduction

Black Silicon Carbide (SiC) stands out as one of the hardest and most versatile synthetic materials in modern industry. Known for its exceptional hardness, thermal conductivity, and resistance to wear, it is widely used in abrasive machining, metallurgy, and advanced ceramics. Despite being discovered over a century ago, technological advances have expanded its applications from traditional grinding wheels to semiconductor devices and solar energy solutions.

This article explores the origins, characteristics, production process, and the diverse industrial uses of black silicon carbide. We will also compare it with green silicon carbide and other abrasives to understand why it remains a cornerstone material for high-performance manufacturing.

 

What Is Black Silicon Carbide?

Black silicon carbide is a compound of silicon and carbon, synthesized through an electric resistance furnace using high-purity silica sand and petroleum coke at temperatures above 2200°C. The resulting material forms hard, shiny black crystals. It typically contains around 98% SiC, with small amounts of free carbon and silicon oxide impurities, which affect its color and toughness.

It is classified under artificial abrasives and ranks second only to diamond and boron carbide in hardness. Its Mohs hardness rating of about 9.2 makes it an excellent material for grinding, cutting, and polishing hard metals, ceramics, and stones.

 

Manufacturing Process of Black Silicon Carbide

The production of black silicon carbide involves several key steps:

  1. Raw Material Preparation – High-quality quartz sand and petroleum coke are mixed in a precise ratio.

  2. High-Temperature Furnace Reaction – The mixture is heated in an electric resistance furnace, forming SiC crystals.

  3. Cooling and Crushing – The furnace mass is cooled, and the SiC is broken down into usable crystal sizes.

  4. Magnetic Separation and Screening – Impurities like metallic silicon and free carbon are removed.

  5. Grading and Packaging – Different grit sizes are separated to match various industrial needs.

This process ensures high purity and uniform crystal structure, crucial for achieving superior abrasive and mechanical performance.

 

Physical and Chemical Properties

Black silicon carbide exhibits remarkable mechanical and thermal properties that make it suitable for demanding environments:

Property Description Typical Value
Chemical Formula SiC —
Color Black —
Hardness (Mohs) Extremely hard ~9.2
Melting Point Sublimes at ~2700°C —
Density Moderate 3.2 g/cm³
Thermal Conductivity High ~120 W/m·K
Electrical Conductivity Semiconductive Varies with temperature
Oxidation Resistance Excellent Up to 1600°C

These properties make black silicon carbide both durable and efficient in abrasive and high-temperature applications.

 

Black Silicon Carbide vs. Green Silicon Carbide

Although both black and green silicon carbide are forms of SiC, their differences in purity and performance define their distinct industrial roles.

Feature Black Silicon Carbide Green Silicon Carbide
Color Black Green
Purity ~98% SiC ~99% SiC
Hardness Slightly lower Higher
Toughness Higher impact resistance More brittle
Applications Grinding metals, stones, ceramics Cutting hard alloys, optical glass, non-ferrous materials
Cost More economical More expensive

In essence, black SiC is tougher and more affordable, making it ideal for heavy-duty grinding and general-purpose abrasive applications, while green SiC excels in precision polishing and semiconductor processing.

 

Key Industrial Applications

 

Abrasives and Grinding

The most common use of black silicon carbide is as an abrasive in grinding wheels, sandpapers, and cutting tools. Its hardness allows it to efficiently cut through steel, cast iron, and stone with minimal wear.

 

Refractory Material

Due to its exceptional heat resistance, black SiC serves as a key component in refractory bricks and crucibles used in furnaces and kilns. It enhances the thermal shock resistance and durability of the materials.

 

Metallurgical Additive

In steelmaking, black silicon carbide acts as a deoxidizer and carburizer, improving the mechanical strength and corrosion resistance of the final metal product.

 

Ceramic and Composite Manufacturing

Black SiC is also used as a reinforcing material in advanced ceramics and composites. It improves hardness, wear resistance, and thermal conductivity without adding much weight.

 

Electronics and Semiconductor Fields

Although green silicon carbide is more commonly used in semiconductor applications, black SiC is finding new relevance in power electronics due to its cost-effectiveness and conductivity properties.

 

Advantages of Using Black Silicon Carbide

  • Extreme Hardness – Provides superior wear resistance in cutting and grinding applications.

  • High Thermal Stability – Performs reliably in high-temperature processes.

  • Excellent Electrical Conductivity – Suitable for conductive abrasives and certain electronic uses.

  • Chemical Inertness – Resistant to acids and oxidation.

  • Cost-Effectiveness – Offers a balance between performance and price compared to diamond or boron carbide.

 

Quality Grades and Standards

Black silicon carbide is available in multiple grades, such as:

  • Macro Grits (F12–F220) – For coarse grinding and lapping.

  • Micro Grits (F230–F1200) – For polishing and fine surface finishing.

  • Refractory Grade – Used in furnace linings and crucibles.

  • Metallurgical Grade – Applied in steelmaking and foundries.

Each grade is standardized under organizations like FEPA, JIS, and ANSI, ensuring consistency in performance and particle size distribution.

 

Choosing the Right Black Silicon Carbide

When selecting black silicon carbide, several factors should be considered:

  • Application Type – Determine whether it is for grinding, polishing, or metallurgical use.

  • Grit Size – Coarser grits for material removal, finer grits for surface finishing.

  • Purity Level – Higher purity offers better performance but at higher cost.

  • Bond Compatibility – Match with resin, vitrified, or metal bonds depending on equipment.

  • Supplier Certification – Always choose certified manufacturers that meet ISO and industry standards.

 

Market Trends and Future Outlook

The global silicon carbide market is witnessing significant growth, driven by expanding applications in electronics, renewable energy, and manufacturing. As industries push for sustainability and energy efficiency, SiC's role in electric vehicles, power devices, and solar panels continues to rise.

Black silicon carbide, with its affordability and high performance, will remain in strong demand for traditional abrasive markets while slowly expanding into hybrid materials and industrial coatings.

 

Maintenance and Storage Tips

Proper storage ensures black silicon carbide retains its performance quality:

  • Store in a dry, ventilated environment to prevent oxidation.

  • Avoid moisture and contamination from other chemicals.

  • Use airtight containers for fine powders.

  • Label each batch clearly to maintain grit and grade traceability.

 

Environmental Impact

Compared to natural abrasives, black silicon carbide offers sustainability benefits. Its reusability in blasting and grinding operations reduces waste, while advancements in furnace technology have decreased energy consumption and carbon emissions in its production.

Furthermore, SiC-based materials are increasingly used in environmental applications such as water filtration and catalytic converters.

 

Conclusion

Black silicon carbide remains a cornerstone material in the industrial world—combining exceptional hardness, heat resistance, and versatility at a competitive price. Whether used for abrasives, metallurgy, or ceramics, it continues to power innovations in manufacturing and materials science. With continuous improvements in production and purification, black SiC is set to play a key role in both traditional and emerging industries.

 

Frequently Asked Questions

1. What is the main difference between black and green silicon carbide?

Black SiC is tougher and more economical, while green SiC is purer and more suitable for precision work.

2. Can black silicon carbide be reused after blasting?

Yes, depending on the application and level of contamination, it can often be recycled multiple times.

3. Is black silicon carbide conductive?

Yes, it has semiconductive properties, allowing limited electrical conductivity.

4. How does black silicon carbide perform in high temperatures?

It maintains structural integrity up to around 1600°C, making it excellent for refractories and foundry use.

5. What industries use black silicon carbide most commonly?

Abrasive manufacturing, metallurgy, ceramics, refractories, and composite materials are the major sectors.

Article Summary 


This comprehensive guide explores black silicon carbide—its properties, production, and applications across abrasives, metallurgy, ceramics, and electronics. It highlights key advantages, compares it with green SiC, and analyzes market trends, offering insights into its industrial relevance and future growth.

Come and contact us to purchase!!!