AlN-Ti₂AlN複合材料合成の試み

抄録

Aluminum nitride (AlN) ceramics are indispensable to semiconductor manufacturing processes because of their high thermal conductivities, high corrosion-resistance to halogen gases and plasmas, high strengths and etc. Titanium aluminum nitride (Ti₂AlN) is a ceramic showing high electrical conductivity and machinability. A Ti-Al-N ternary equilibrium diagram indicates a two-phase equilibrium region between Ti₂AlN and AlN, which motivated the synthesis of AlN-Ti₂AlN composites with added electrical conductivity and machinability to AlN ceramics in a wide temperature range. In this study, an approach to the synthesis of AlN-Ti₂AlN composites was made by reactive hot-pressing of Ti/Al/TiN/AlN and Ti/AlN powder mixtures, respectively. Before synthesizing the composites, synthesis of single-phase Ti₂AlN has been pursued and almost single-phase Ti₂AlN was successfully obtained by the reactive hot-pressing of a Ti/Al/TiN powder mixture with a molar ratio of Ti:Al:TiN=1:1:1 and a Ti/AlN powder mixture with the ratio of Ti:AlN=2:1, respectively. However, all attempts to synthesize AlN-Ti₂AlN composites by the reactive hot-pressing of a Ti/Al/TiN/AlN powder mixture with the ratio of Ti:Al:TiN:AlN=1:1:1:9 or a Ti/AlN mixture with the ratio of Ti:AlN=1:1 did not succeed, and the cause of these results are discussed.