Y2O3 함량과 소결조건에 따른 상압소결 AlN 세라믹스의 열전도도 고찰 |
나상문, 고신일, 이상진1 |
(주)와이제이씨 1국립목포대학교 신소재공학과 |
Observation of Thermal Conductivity of Pressureless Sintered AlN Ceramics under Control of Y2O3 Content and Sintering Condition |
Sang-Moon Na, Shin-Il Go, Sang-Jin Lee1 |
YJC Co., LTD. 1Department of Advanced Materials Science and Engineering, Mokpo National University |
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ABSTRACT |
Aluminum nitride (AlN) has excellent thermal conductivity, whereas it has some disadvantage such as low sinterability. In this study, the effects of sintering additive content and sintering condition on thermal conductivity of pressureless sintered AlN ceramics were examined on the variables of 1~3 wt% sintering additive ($Y_2O_3$) content at $1900^{circ}C$ in $N_2$ atmosphere with holding time of 2~10 h. All AlN specimens showed higher thermal conductivity as the $Y_2O_3$ content and holding time increase. The formation of secondary phases (yttrium aluminates) by reaction of $Y_2O_3$ and $Al_2O_3$ from AlN surface promoted the thermal conductivity of AlN specimens, because the secondary phases could reduce the oxygen contents in AlN lattice. Also, thermal conductivity was increased by long sintering time because of the uniform distribution and the elimination of the secondary phases at the grain boundary by the evaporation effect during long holding time. A carbothermal reduction reaction was also affected on the thermal conductivity. The thermal conductivity of AlN specimens sintered at $1900^{circ}C$ for 10 h showed 130~200W/mK according to the content of sintering additive. |
Key words:
AlN, Thermal conductivity, Sintering, $Y_2O_3$, Microstructure |
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