Heating aluminum nitride with reducing additives to produce high thermal conductivity ceramics

Abstract From the Canadian patent

A process for producing an aluminum nitride ceramic body having a composition defined and encompassed by polygon FJDSR but not including line RF of Figure 4 a, porosity of less than about 10% by volume and a thermal, conductivity greater than 1.00 W/cm?K at 25°C which comprises forming a mixture comprised of aluminum nitride powder containing oxygen, yttrium oxide, and free carbon shaping, said mixture into a compact, said mixture and said compact having a composition wherein the equivalent % of yttrium and aluminum ranges from point D up to point F of Figure 4 said, compact having an equivalent % composition of Y Al, O and N, outside the composition defined and encompassed by polygon FJDSR …