How to identify quality problems in silicon carbide products

How to Identify Quality Issues in Silicon Carbide Products

With the development of science and technology, my country's cement industry is constantly improving its skills, thus raising the requirements for refractory materials. Silicon carbide products are widely used in the cement industry due to their high-temperature resistance. So, how can one identify the quality of silicon carbide products?

How to Identify Quality Issues in Silicon Carbide Products

A simple method for checking the quality of silicon carbide products is to tap the center of the product with a hammer and listen to the sound. If the sound is dull, it indicates that the silicon carbide product has voids or delamination in the center, making it unsuitable for building cement kilns. If the sound is even but has a reverberation, it indicates that the internal structure of the silicon carbide product is intact and it can be used for processing. If the sound is crisp, like the sound of metal, it indicates that the silicon carbide product has a high degree of internal sintering, making it difficult to process.

The chemical composition of silicon carbide products also determines their special properties. For example, they remain intact under conditions of constant and rapid temperature changes, can withstand high pressure during shearing, and are not easily deformed at very high temperatures, meaning they have strong resistance to high temperatures.

Main Formulations of Silicon Carbide Products

In my country, industrial silicon carbide products are divided into black silicon carbide and green silicon carbide. So, which type of silicon carbide should be used when manufacturing silicon carbide products? Below, a silicon carbide product manufacturer will provide a detailed analysis of this issue.

Silicon carbide products have two common matrices: black silicon carbide and green silicon carbide, both belonging to the SiC family.

1. Black silicon carbide contains approximately 95% SiC and has higher toughness than green silicon carbide. It is mainly used for processing materials with low tensile strength, such as glass, ceramics, stone, refractory materials, cast iron, and non-ferrous metals.

2. Green silicon carbide contains over 97% SiC and has good self-sharpening properties. It is mainly used for machining cemented carbide, titanium alloys, and optical glass, as well as for honing cylinder liners and grinding high-speed steel tools. In addition, there is cubic silicon carbide, a yellowish-green crystal produced through a special process. Abrasives made from it are suitable for ultra-precision machining of bearings, achieving surface roughness from Ra32~0.16 micrometers to Ra0.04~0.02 micrometers in a single pass.

Types and Uses of Silicon Carbide Products

1. Applications in Non-ferrous Metal Smelting Industry

Silicon carbide possesses high temperature resistance, high strength, good thermal conductivity, and impact resistance, making it suitable as a high-temperature indirect heating material, such as in hard-packed distillation furnaces. Applications include distillation furnace trays, aluminum electrolytic cells, copper smelting furnace linings, arc plates for zinc powder furnaces, and thermocouple protection tubes.
2. Applications in the Steel Industry

Utilizing silicon carbide's corrosion resistance, thermal shock resistance, and wear resistance, along with its good thermal conductivity, it can be used in large blast furnace linings to extend their service life. Utilizing its high thermal conductivity, high heat dissipation, and high thermal strength, silicon carbide is used to manufacture thin-plate kiln furniture. This not only reduces kiln furniture production capacity but also increases it, improves product quality, and shortens the production cycle. It is an ideal indirect material for firing and sintering ceramic glazes.

3. Applications in the Metallurgical and Mineral Processing Industries

Silicon carbide has a hardness second only to diamond and possesses strong wear resistance. It is an ideal material for wear-resistant pipes, impellers, pump chambers, cyclone separators, and hopper linings. Its wear resistance is 5-20 times that of cast iron and rubber, making it one of the ideal materials for aircraft runways.