Silicon carbide (SiC) crucibles consist of tetrahedrally coordinated silicon and carbon atoms in a covalently bonded crystal lattice. The structure has unique properties including a melting point of 2730°C, a thermal conductivity of 120-170 W/m-K and a Mohs hardness of 9.

SIC are resistant to thermal shock due to their low coefficient of thermal expansion (4.0-4.5 µm/m-K) and high fracture toughness. They are also resistant to oxidation and corrosion from molten metal and slag in high-temperature processes. High thermal conductivity improves metallurgical process efficiency with easy heat transfer. SIC also last longer in harsh environments. Advanced materials processing, electronics manufacturing and high purity metal refining require stability to maintain quality during high temperature treatments.

Applications for Silicon Carbide Crucibles 

Laboratory use

The thermal stability and chemical resistance of silicon carbide crucibles are suitable for high temperature experiments and reactions in chemical laboratories. Calcination, pyrolysis and high temperature synthesis require these crucibles to withstand temperatures up to 1900°C. In the synthesis of new ceramic materials, they allow precise temperature control and homogeneous heat distribution. Their thermal conductivity allows them to heat and cool rapidly, reducing temperature gradients and sample contamination. Thermal shock resistance makes them safe in dynamic laboratory situations. Silicon carbide material is unlikely to shatter under harsh conditions, ensuring reliability over multiple test cycles.

Foundry use

Foundries use silicon carbide crucibles for casting and melting iron and steel. The SIC crucibles can withstand high temperature metal processing at melting points in excess of 2700°C. For example, they limit heat loss and distribute heat evenly in steel foundries for more efficient melting. It also helps to reduce energy consumption and melting time. Because the crucibles are chemically inert and do not react with molten metals, contamination is reduced. Stainless steels and alloys require this inertness to remain pure. SIC crucibles also last longer, reducing delays and replacements. As a result, foundries enjoy improved productivity and lower manufacturers costs by using sintered silicon carbide crucibles.

Other industrial applications pf sintered silicon carbide crucibles for sale

Silicon carbide crucibles for sale are also used in the manufacture of glass and solar panels. Such crucibles melt raw glass in glass-blowing workshops due to their thermal conductivity. High quality glass products with few defects require this consistency. On the other hand, photovoltaic cells are made from silicon wafers in silicon carbide crucibles. The crucibles produce defect-free silicon crystals for efficient solar cells due to their purity and thermal stability. As a result, silicon carbide crucibles are used in high-temperature industrial operations due to their reliability and low maintenance costs.

Manufacture of silicon carbide crucibles

Silicon carbide crucibles are manufactured by starting with high purity raw materials (silicon carbide powder) mixed with phenolic resin and then pressing the mixture into the desired shape using isostatic or uniaxial pressing. After drying, these green bodies are sintered at temperatures of 1600-2100°C in a controlled environment to increase mechanical strength and thermal conductivity.

SIC crucibles range from small laboratory crucibles a few centimetres wide to large industrial crucibles over a metre wide for different volume requirements. Cylindrical, conical and rectangular shapes are used for metal melting and chemical processing. However, there are ways to customise wall thickness, capacity and thermal properties to meet industrial needs, including high temperature stability for metallurgical operations or chemical resistance for laboratory use. Meanwhile, vitrification surface treatment can improve crucible strength and efficiency.

Sintered Silicon Carbide Crucibles For Sale

At Sialon Ceramics LTD, we are manufacturers of sintered silicon carbide crucibles that resist chemical degradation and thermal shock up to 1,900°C in controlled atmospheres. Specifically, our XICAR® crucibles can withstand 1,650°C in air at 3,000 mm length and 300 mm OD. They also maintain mechanical strength at high temperatures for casting. Our thermocouple protection tubes, compatible with type R or S elements, accurately monitor temperatures in molten brass, copper and stainless steel for performance. Our crucibles meet or exceed HEXOLOY SE quality requirements.