The influence of columnar microstructure on diffusion reaction between Ti thin films and aluminum nitride ceramics

In this paper, Ti films with certain thickness were deposited on a polished AlN ceramic substrates by direct current magnetron sputtering at room temperature (RT) and 400 °C, respectively. After deposition, the samples were annealed at 600 °C for 1 h in the mixture gases of argon and hydrogen atmosphere. The microstructure of the Ti films and interface reaction products between Ti/AlN were investigated using X-ray diffraction, and transmission electron microscopy. The effects of deposition temperature on the microstructure and grain orientation of Ti films were studied. It is found that the decomposition of AlN would mainly take place at the AlN/Ti interface during the heat-treated process. After annealing, Al and N react with Ti to produce AlTi₃N in the film deposited at 400 °C, while TiN_0.3 be formed if deposited at RT. The subsequent rolling-contact-fatigue test proved that after annealing at 600 °C for 1 h, the adhesion strength of Ti/AlN interface deposited at 400 °C is superior to that deposited at RT.