The effects of two different heat-treatment atmospheres,nitrogen atmosphere and reducing nitrogen atmosphere with carbon,on the properties of Y2O3-doped aluminum nitride(AlN) ceramics were investigated.The AlN powder as a raw material was synthesized by self-propagating high-temperature synthesis(SHS) and compacts were fabricated by employing powder injection molding technique.The polymer-wax binder consisted of 60 wt.% paraffin wax(PW),35 wt.% polypropylene(PP),and 5 wt.% stearic acid(SA).After the removal of binder,specimens were sintered at 1850°С in nitrogen atmosphere under atmospheric pressure.To improve the thermal conductivity,sintered samples were reheated.The result reveals that the heat-treatment atmosphere has significant effect on the properties and secondary phase of AlN ceramics.The thermal conductivity and density of AlN ceramics reheated in nitrogen gas are 180 W·m-1·K-1 and 3.28 g·cm-3 and the secondary phase is yttrium aluminate.For the sample reheated in reducing nitrogen atmosphere with carbon,the thermal conductivity and density are 173 W·m-1·K-1 and 3.23 g·cm-3,respectively,and the secondary phase is YN.
DU XueliQIN MingliAkhtar FaridFENG PeizhongQU Xuanhui
