A new production process for high-quality durable ceramics is leading to ultra-strength materials. Dutch ceramics producers Ceratec have demonstrated a sintered form of the extremely hard-wearing ceramic silicon-carbide, which could now see use in applications from precision insulators to spacecraft.
Silicon carbide has been known for many years (and it occurs naturally in tiny amounts), but the sintering process now developed is innovative as it creates solid, machine-crafted pieces for heavy duty applications. Sintering is the fusing of two separate pieces of a single material under high pressure, temperature, or both.
Sintering can result in high-strength bonds, particularly in materials with a crystalline structure. Common, relatively weak sintering occurs in salt or ice, when blocks are compressed.
The novelty in this ceramic process is that the machining takes places before the sintering. Using silicon dioxide and carbon, silicon carbide is produced with carbon dioxide as a by-product. The material is extremely hard, very stiff and wear-proof. In addition, the Ceratec process results in an exceptionally flat, workable surface, with discrepancies of just 20 nm.
Due to its good chemical resistance, silicon carbide can be properly used in all kinds of extreme conditions. After the sintering process, the material shrinks by about 20%. For its strength, the result is a relatively light-weight material (around 3,1 g/cm3), with a stiffness of 410 GPa and good thermal conductivity of 110 W/mK. More information and images via the producer, Ceratec.