Abstract:
Development of advanced ternary nitride coatings such as titanium aluminium nitride and
titanium vanadium nitride has attracted significant industrial interest in recent years. Titanium
vanadium nitride is considered one of the advanced ternary nitride coatings of great commercial
potential. It is believed with the additional element, the oxidation resistance of the coatings can be
greatly improved at elevated temperatures. Furthermore, the type of elements selected can produce
unique coating properties that can be beneficial to machining of different materials. This paper is to
report a study on the structural stability of nanostructured titanium vanadium nitride coatings in
high temperature annealing. Nanostructured titanium vanadium nitride coatings were produced by
reactive magnetron co-sputtering on AISI H13 tool steel substrates at 240°e. Heat treatment was
applied to the coatings at temperatures up to 1000oe. It was found that an unexpected grain
refinement of the coatings occurred in the heat treatment process. Grain size of the coatings was
found to decrease from ~200-300 nm to ~150 nm after the heat treatments. A strong TiN/TiVN
(200) component was found to exist at temperatures up to 7000e but was depleted at higher
annealing temperatures. With a finer and densified grain structure, the hardness of the coatings
substantially increased from ~800 HV to ~ 1700 HY.
