Abstract:
This paper is to study the thermal stability of nanocrystalline ternary nitride coatings at elevated temperatures.
Nanocrystalline titanium aluminium nitride coatings were produced by reactive magnetron co-sputtering on glass
substrates and AISI Hl3 tool steel substrates with nitrogen pressures of 0.4 and 0.65 mTorr (0.053 and 0.086 Pa)
respectively. Heat treatment was applied to the coatings at temperatures up to 1000°C. It was found that an unexpected
grain refinement occurred in the coatings deposited at 0.4 mTorr nitrogen pressure after the heat treatment. A stronger
development of TiN/TiAIN (200) component was also evident at temperatures above 800°C. With a finer and densified
grain structure, the hardness of the coatings increased substantially from -1700 to 2300 HV.
