Boron carbide modulus

Silicon carbide is noted for its extreme hardness [182-184], its high abrasive power, high modulus of elasticity (450 GPa), high temperature resistance up to above 1500°C, as well as high resistance to abrasion. The industrial importance of silicon carbide is mainly due to its extreme hardness of 9.5-9.75 on the Mohs scale. Only diamond, cubic boron nitride, and boron carbide are harder. The Knoop microhardness number HK-0.1, that is the hardness measured with a load of 0.1 kp (w0.98N), is 2600 (2000 for aAl203, 3000 for B4C, 4700 for cubic BN, and 7000-8000 for diamond). Silicon carbide is very brittle, and can therefore be crushed comparatively easily in spite of its great hardness. Table 8 summarizes some typical physical properties of the SiC ceramics. 

The light weight, high modulus and high sound velocity of boron carbide (Table 11.1) are utilized in a large variety of military and personnel armor applications (see Section 7.1.4.3). The high thermal neutron capture cross-section of 600 barns (6 X 10 m ) provides neutron absorption capability for wet and dry spent nuclear fuel storage and transport applications, and possibly for the first wall protection of nuclear fusion reactors (Van der Laan et al., 1994 Buzhinskij et al., 2009). 

Boron carbide is a lightweight refractory material with high hardness and Young s modulus, aud excellent thermoelectric properties. The material is a water-resistant ceramic and has very high... 

Boron and Silicon-Carbide Fibers. Boron and silicon-carbide (SiC) fibers have high strength and modulus, but have low oxidation resistance and high cost. They are produced by chemical-vapor deposition (CVD) and sol-gel methods. 

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