“…1 Accordingly, the preparation of bulk AlN has been intensively investigated during the last decades in order to use as refractories. 1 However, the covalent bonding between Al and N makes the sintering of AlN difficult without the application of sintering additives. 2 Consequently, additives such as Li 2 O, CaO, MgO, MgO-SiO 2 , SiO 2 , B 2 O 3 , NiO, Cr 2 O 3 , Y 2 O 3 , CaF 2 and Ni have been used in order to promote the densification of AlN.…”