Thin Solid Films, Vol.382, No.1-2, 101-105, 2001
Hot-pressed Ti-Al targets for synthesizing Ti1-xAlxN films by the arc ion plating method
Ti and Al powders were mixed with identical atomic ratios and hot-pressed at 650, 800, 950, 1100 and 1250 degreesC, respectively, for the use of targets in the are ion plating (AIP) method. As the sintering temperatures increased, the target density monotonously increased and the porosity correspondingly decreased. Chemical analysis by X-ray diffraction indicated that pure Ti and Al phases decreased and intermetallics such as TiAl3 and Ti3Al phases were formed at 800-950 degreesC. Over 950 degreesC, the amount of the intermetallics decreased and finally TiAl phase was formed. Next, the Ti-Al targets were are-discharged in nitrogen plasma and Ti1-xAlxN films were deposited on mirror-polished cemented carbide substrates. The targets with lower density, sintered at 650 and 800 degreesC, did not easily trigger and keep stable are-discharge during the deposition. As a result, synthesized Ti1-xAlxN films had a larger number and size of droplets which were not only circular but were also irregular shapes. Although microstructures of Ti-Al targets were quite different, all films mostly consisted of Ti0.5Al0.5N with the NaCl structure and similar hardness with approximately 3000 HV. Further, all Ti0.5Al0.5N films had the same columnar cross-sectional structures and the growth rate was approximately 17 mum/h.