Publication date: Available online 1 December 2015
Source:Thin Solid Films
Author(s): Z.L. Wu, Y.G. Li, B. Wu, M.K. Lei
TiAlSiN nanocomposite coatings were deposited in a closed field unbalanced magnetron sputtering system by reactive sputtering from Ti0.475 Al0.475 Si0.05 targets using modulated pulsed power magnetron sputtering (MPPMS) under a floating substrate bias. The ratio of the nitrogen flow rate to the total gas flow rate (f N2 ) was varied from 0 to 40%. The application of MPPMS as sputtering sources was aimed at generating a high ionization degree of the sputtered material and a high plasma density by using a pulsed high power approach. When f N2 0.479 Al0.454 Si0.066 coating was deposited with a hardness of 10nc -TiAlN/a -Si3 N4 formed in the TiAlSiN coating deposited at f N2 3 N4 matrix. As the f N2 was increased up to 40%, the elementary composition of the coatings remained almost the same, but the grain size of nanocrystallites approached to 10–20f N2 The friction coefficient of the TiAlSiN coatings was around 0.8–0.9 as sliding against a Si 3 N 4 counterpart under a normal load of 0.5 N. A wear rate of 2.0 × 10 − mm 3 N − m − was measured in the TiAlSiN coatings deposited at f N2 = 20–40% . As only a low residual stress is found in the TiAlSiN coatings, we consider the complete phase separation is responsible for the enhanced mechanical and tribological properties of the nc -TiAlN/a -Si3 N4 nanocomposite coatings.
Source:Thin Solid Films
Author(s): Z.L. Wu, Y.G. Li, B. Wu, M.K. Lei