Improvement of Hardness and Toughness of TiAlN Coatings
by Nanoscale Multilayered Structurization with
Amorphous Si-N Phase
* Korea Institute of Science and Technology, P.O. Box 131,
Cheongryang, Seoul 130-650,
South Korea
**
Forschungszentrum Karlsruhe, Institut
für Materialforschung I, Hermann-von-Helmholtz-Platz
1, 76344 Eggenstein-Leopoldshafen, Germany
Recently, Ti(-Al)-Si-N nanocomposite coatings
were known to have excellent hardness and high temperature stability, compared
to the TiAlN coatings. In this study, we have investigated the microstructure,
hardness and toughness of TiAlN/a-Si-N nanoscale mulilayered coatings. The
TiAlN/a-Si-N nanoscale mulilayered coatings were deposited on M2 HSS and Si
wafer by D.C. magnetron sputtering with TiAl alloy and Si targets. N2
and Ar were the reactive gases.
Bilayer period of nanomultilayer was controlled by changing rotation speed of
substrate holder. For a fixed rotation speed, relative thicknesses of the amorphous Si-N and crystalline TiAlN were also controlled by
changing Si and TiAl target power
density. The phase, microstructure and hardness of the obtained coatings were measured.
Toughness of the TiAlN/a-Si-N was assessed by nanoindentation technique.
Changes in hardness and toughness of the coatings after heat-treatment in N2
atmosphere were also investigated. Effect of bilayer period and relative
thicknesses of amorphous Si-N and
crystalline TiAlN on the hardness and toughness of the
TiAlN/a-Si-N nanoscale mulilayered coatings will be discussed.
This research was
supported by a grant (code # : M60401000171-05A0100-17110) from International
Collaborative R&D Programs of the Ministry of Science and