2006 Volume 114 Issue 1326 Pages 167-173
Hexagonal boron nitride (h-BN) dispersed nanocomposites were fabricated through a chemical process involving sintering of matrix ceramic powders covered partly with turbostratic BN (t-BN), which was synthesized by the reduction of a mixture of boric acid and urea precipitating on the matrix ceramic powder during drying after wet-ball milling. Silicon carbide (SiC), silicon nitride (Si3N4), alumina (Al2O3) and aluminum nitride (AlN) were employed as matrix for h-BN dispersed nanocomposites. The nano-sized h-BN particles were found to be homogeneously dispersed within the matrix grains as well as at grain boundaries, which is typical of nanocomposite structures. As a result, the present nanocomposites showed unique and excellent properties such as high strength, low Young's modulus, high thermal shock resistance, and good machinability.
