직접질화법 AlN 분말의 소결거동 및 열전도도에 미치는 고에너지 볼밀링 효과

초록

In this study, a high energy ball milling process was introduced in order to improve the densification of direct nitrided AlN powder. The sintering behavior and thermal conductivity of the AlN milled powder was investigated. The mixture of AlN powder and 5 wt% Y2O3 as a sintering additive was pulverized and dispersed by a bead mill with very small ZrO 2 bead media. The milled powders were sintered at 1700°C-1800°C for 4 h under N2 atmosphere. The results showed that the sintered density was enhanced with increasing milling time due to the particle refinement as well as the increase in oxygen contents. Appropriate milling time was effective for the improvement of thermal conductivity, but the extensive millied powder formed more fractions of secondary phase during sintering, resulted in the decrease in thermal conductivity. The AlN powder milled for 10min after sintering at 1800°C revealed the highest thermal conductivity, of 164W/m K in tne densified AlN sintered at 1800°C.

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