SiC whisker (SiCw) is a kind of single-crystal fiber with high orientation ranging from nanometer to micron in diameter. Its crystal structure is similar to that of diamond. There are few chemical impurities in the crystal, no grain boundary, few crystal structure defects and uniform crystal phase composition. It has the characteristics of high melting point, low density, high strength, high elastic modulus, low thermal expansion rate, abrasion resistance, corrosion resistance, high temperature oxidation resistance and so on. It is mainly used for toughening materials with high temperature and high strength. The relevant indicators are shown in the following table:
Melting point
> 2700 ℃
The density of
3. 21 g/cm3
Tensile strength
2100 kg/cm2
Modulus of elasticity
4. 9 x 104 kg/cm2
SiCw comes in two crystal forms, SiCw alpha (hexagonal and rhombic) and SiCw beta (face centered cubic), and SiCw is superior to alpha in all aspects of performance. At present, industrial scale production has been achieved only by beta SiCw, so beta SiCw is mainly studied and used.
