Abstract
The reaction temperature in the combustion synthesis of AlN was controlled by adding H2 gas to the reactant N2 gas in order to reduce the particle size of the products. The addition of 20 vol.% H2 to reactant N2 gas decreased the combustion temperature from 2680 K to 2300 K. This led to an increase in specific surface area (SSA) of the product from 1.02 m2 · g-1 to 1.58 m2 · g-1. When 1.0 mass% of NH4F was added to the mixture of the raw Al powder and the AlN diluent, the residual Al was reduced from 1700 ppm to 200 ppm. The AlN powder synthesized with the addition of 10 vol.% of H2 gas and 1.0 mass % of NH4F was fully densified at 1810°C under 0.11 MPa of N2 pressure for 180 min. The thermal conductivity of the sintered AlN measured by laser flash method was 160 W · m-1K-1.
