EFFECT OF SECOND PHASE AFTER-HEAT TREATMENT ON THE THERMAL CONDUCTIVITY OF AlN CERAMICS

The effect of microstructure on the thermal conductivity of AlN ceramics was investigated. An AlN ceramic was prepared with Y2O3 dopant under a reducing nitrogen atmosphere with carbon. To obtain high thermal conductivity, cooling rate control and after-heat treatment was carried out. The morphology of the secondary phase was characterised using SEM which showed that the microstructural change caused by after-heat treatment had a major influence on the thermal conductivity.