Synthesis of an aluminum nitride–yttria (AlN–Y_20_3)composite from nano-sized porous AIN and YCl_3

摘要

Abstract In order to enhance the thermal conductivity of aluminum nitride (AIN) with sintering additives including yttria (Y_20_3), it is necessary to form yttrium aluminate garnet (YAG) and secondary phases both within and around the boundaries of AIN drains. Nano-sized porous AIN particles were produced to form YAG and secondary phases within AIN grains, after which a AIN—Y_2 0_3 nano—nano composite was formed from AIN and amorphous Y_20_3. Porous AlN powders were first successfully synthesized by the chemical vapor synthesis (CVS) method. Highly crystalline and nano-sized porous AIN powders were synthesized at 1,200 °C. Brunauer—Emmett—Teller (BET) analysis showed that these powders had very large surface areas, suggesting that the particles approached nano-scale sizes with very small pores. To form composites of Y_20_3 and AlN, we prepared a yttrium source solution that infiltrated the nano-sized pores of the AlN particles. Such an infiltration of AlN with amorphous Y_20_3 was expected to effectively reduce the residual oxygen content by facilitating the formation of YAG and secondary phases during the sintering process. We characterized the composite powders of AlN—Y_20_3 and the sintered bodies using BET, XRD, SEM, TEM, and thermal conductivity analyses.