Novel technique for synthesis and consolidation of aluminium nitride nanopowders

In this paper, the use of a microwave plasma method for the synthesis of al uminium nitride nanopowders is described. The powders were consolidated to near theoretical densities using the unique rapid consolidation technique, plasma pressure consolidation ((PC)-C-2), developed by MMI. Rapid consolida tion of nanopowders is an ideal requirement for better mechanical and therm al properties in the consolidated part, as it retains the fine microstructu re preventing anomalous grain growth. Microwave plasma synthesis resulted i n aluminium nitride nanopowders (85-200 nm), which were consolidated to nea r theoretical density using (PC)-C-2 in <5 min without sintering additives. The effect of yttria (3 wt-%) as a sintering additive on the thermal condu ctivity (TC) of aluminium nitride was also evaluated and compared with TC v alues obtained from additive free AIN consolidated samples.