Sintering behavior of direct nitrided AlN powder

• Published in: Materials letters Vol. 46; no. 2; pp. 98 - 104
• Main Authors: Tajika, Masahiko, Rafaniello, William, Niihara, Koichi
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2000; Elsevier
• Subjects: Aluminum nitride powder; Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; Exact sciences and technology; Microstructure; Miscellaneous; Particle size distribution; Shrinkage; Sintering; Technical ceramics; Thermal conductivity; Thermal conductivity; Particle size distribution; Aluminum nitride powder; Shrinkage; Microstructure; Sintering; Experimental study; Powder; Non oxide ceramics; Thermal properties; Aluminium Nitrides; Additive; Yttrium Oxides; Chemical preparation; Manufacturing
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/S0167-577X(00)00149-X

Classified direct nitrided (DN) aluminum nitride (AlN) powders were examined by dilatometry to study the effect of particle size on sinterability. The shrinkage behavior of three DN powders was compared to that of a commercial, carbothermally produced, AlN powder. Yttrium oxide was added to AlN powder as a sintering aid. Two distinct features of the resulting shrinkage curves, corresponded to particle rearrangement coincident with yttrium aluminate formation and high temperature sintering. The presence of coarse particles in the original DN powder, greater than 8 μm, distinguished it from the other powders studied and appeared to have the greatest influence on the sintering behavior. For fine powders without coarse particles (>8 μm), the synthesis method did not seem to affect the shrinkage. The grain size distribution of the sintered parts mirrored the particle size distribution of the four powders studied. Thermal conductivity (TC) of the sintered AlN bodies was strongly dependent on the oxygen content of the starting powders.