Effects of carbothermal reduction on the thermal and electrical conductivities of aluminum nitride ceramics

• Published in: Ceramics international Vol. 36; no. 7; pp. 2039 - 2045
• Main Authors: Kim, Hui-sik, Chae, Jung-min, Oh, Yoon-suk, Kim, Hyung-tae, Shim, Kwang-bo, Lee, Sung-min
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-09-2010
• Subjects: Aluminum nitride; Carbon; Carbothermal reduction; Ceramics; Electrical conductivity; Electrical resistivity; Grain boundaries; Reduction; Resistivity; Thermal conductivity; Yttrium oxide; Thermal conductivity; Electrical conductivity; Carbothermal reduction; Aluminum nitride
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2010.04.001

This study attempts to control the oxygen content by adding various amounts of yttria sintering additives or by introducing an
in situ carbothermal reduction using a carbon addition during the Power processing step. While both yttria and the carbon addition increased the thermal conductivity and electrical resistivity, carbon addition was more effective in increasing the DC volume resistivity for specimens that had 3 or 5
wt% Y
2O
3. Among several elements of the electrical conductivities of the grains and grain boundaries, the conductivity of the grains appeared to be more relevant to the thermal conductivities of AlN ceramics. In addition, yttrium enrichment was observed in the grain boundary region. We also found that an
in situ carbothermal reduction resulted in a small amount of yttrium-aluminate second phases, which are beneficial to the plasma resistance of the AlN ceramics.