Boron nitride (BN) with disordered structure was formed from crystalline hexagonal BN by high-energy mechanical grinding under an inert gas atmosphere and consolidated to a relative density of 92 percent by spark plasma sintering above at 1600 deg C and 40MPa without the use of additives. A sharp increase in density in the temperature region 1500 -1600 deg C was associated with a sharp decrease in the disorder. During the densiflcation with ordering, the basal plane (002) of h-BN was preferably aligned with the facet parallel to the pressure direction which stood in contrast to the grain orientation in the BN oriented from crystalline h-BN powder. The bending strength and direct elastic modulus was 110MPa and 49GPa, respectively.
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