Preparation of single-phase Ti 2 AlN coating by magnetron sputtering with cost-efficient hot-pressed Ti-Al-N targets

Abstract In the present research, single-phase Ti 2 AlN coatings were prepared on polycrystalline Al 2 O 3 from cost-efficient hot-pressed Ti-Al-N targets by D.C. magnetron sputtering and subsequent annealing treatment. SEM, TEM and XRD analyses were performed to characterize the microstructure and phase constituents of the Ti-Al-N target and coating. The results reveal that phase constituents of hot-pressed Ti-Al-N targets were affected by the synthesis temperature. When the synthesis temperature was 700 °C, the target mainly comprised α-Ti, TiN and Ti-Al intermetallics. While in the target synthesized at 900 °C, TiN, Ti-Al intermetallics and Ti 2 AlN were the main phase constituents. The as-deposited coatings from both targets exhibited typical amorphous crystal structure．Crystallization of the coating initiated between 500 °C and 600 °C. After annealing at 700 °C for 1 h, the amorphous coating was transformed to single-phase polycrystalline Ti 2 AlN coating. In general, single-phase Ti 2 AlN coatings could be obtained from the target whether with Ti 2 AlN or not. It was the element ratio of Ti:Al:N = 2:1:1 (at%) rather than the phase contents in the targets that was critical to fabricate single-phase Ti 2 AlN coating.