Influence of incorporation of Cr and Y on the wear performance of TiAlN coatings at elevated temperatures

Wear and friction of TiAlN/VN coatings against Al2O3 in air at room and elevated temperatures

“…This is much higher than reported by Fateh et al [8], who observed a value of 0.5 for VN tested at 300 0 C. In contrast, Pfluger et al [26] observed a value of 1.5 at 400 0 C for TiAlN deposited by the same method used in the current work. Thus, assuming friction coefficient of TiAlN at 400 0 C is similar to 300 0 C, the friction observed for TiAlN/VN (V: 55.2 at.%) here of 1.0 appears to be mid-way between that for VN and TiAlN, implying a simple law of mixtures, 1.5 x 44.8% + 0.5 x 55.2% = 0.95.…”

Modern materials for forming and cutting tools – overview

“…These columns can reach significantly larger sizes without the presence of yttrium in the coating. Yttrium also contributes to a strongly fine grained microstructure [45,46,50,51]. Additionally, the mechanical properties can be improved by yttrium.…”

Characteristics and machining applications of Ti(Y)N coatings

“…This is consistent with the results obtained by Donohue et al who reported that the incorporation of yttrium (2 at.%) with an estimated primary repeating frequency of 1.5 nm into the TiAlCrN lattice was found to promote a significantly finer-grained microstructure. It may be attributed the renucleation to Y surface segregation during deposition [18].…”

“…It was reported that the oxidation resistance of TiAl alloys could be greatly improved by adding a small amount of the rare-earth element yttrium [15,16]. Donohue et al reported that the diffusion barrier effect of the incorporated yttrium became particularly important for testing temperatures exceeding 800°C, and the onset of rapid oxidation, as determined from thermo-gravimetric measurements, ranged from ≈ 600°C for TiN to 870°C for Ti 0.46 Al 0.54 N to 920°C for Ti 0.44 Al 0.53 Cr 0.03 N to 950°C for Ti 0.43 Al 0.52 Cr 0.03 Y 0.02 N [17,18]. Li et al studied influence of yttrium on the interface valence electron density of thermal barrier coatings, and the results showed that the addition of yttrium had beneficial effect on the decrease of the interface stress and the increase of the interface cohesion force [19].…”