TY - JOUR
T1 - Fabrication of Ta-Si-C targets and their utilization for deposition of low friction wear resistant nanocomposite Si-Ta-C-(N) coatings intended for wide temperature range tribological applications
AU - Bondarev, A. V.
AU - Vorotilo, S.
AU - Shchetinin, I. V.
AU - Levashov, E. A.
AU - Shtansky, D. V.
N1 - Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2019/2/15
Y1 - 2019/2/15
N2 - Powders based on tantalum disilicide and silicon carbide were fabricated by mechanical activation-assisted SHS of reaction mixtures, with SiC concentration varied from 10 to 70%. The single- and double-layer composite targets were produced by hot pressing and further utilized for deposition of Si-Ta-C-(N) coatings by magnetron sputtering. The optimal hot pressing regimes, which allowed the production of dense ceramics with a hierarchical structure at 10 and 30% SiC, were determined. These ceramics were characterized by a relative density of 96–97%, hardness of ~19 GPa, and fracture toughness of 6.5–6.7 MPa × m1/2. The nanocomposite Si-Ta-C-N coatings consisted of fcc Ta(Si,C,N) solid solution (TaSi2–30%SiC target) and Ta5Si3 compound (TaSi2–10%SiC target) embedded in an amorphous matrix. Depending on the elemental composition, hardness and Young's modulus of the coatings were 16–26 GPa and 155–268 GPa, respectively. The coatings are characterized by high thermal stability and oxidation resistance at temperatures up to 800 °C. Tribological tests demonstrated the decrease of the coefficient of friction (CoF) of the coatings with increasing temperature: from 0.38 (25 °C) to 0.28 (600 °C) and 0.23 (800 °C). The low wear rate and CoF of the Si-Ta-C-N coatings at elevated temperatures are explained by the formation of a thin (~100 nm) oxide layer and TaSixOy microfibers on the coating surfaces.
AB - Powders based on tantalum disilicide and silicon carbide were fabricated by mechanical activation-assisted SHS of reaction mixtures, with SiC concentration varied from 10 to 70%. The single- and double-layer composite targets were produced by hot pressing and further utilized for deposition of Si-Ta-C-(N) coatings by magnetron sputtering. The optimal hot pressing regimes, which allowed the production of dense ceramics with a hierarchical structure at 10 and 30% SiC, were determined. These ceramics were characterized by a relative density of 96–97%, hardness of ~19 GPa, and fracture toughness of 6.5–6.7 MPa × m1/2. The nanocomposite Si-Ta-C-N coatings consisted of fcc Ta(Si,C,N) solid solution (TaSi2–30%SiC target) and Ta5Si3 compound (TaSi2–10%SiC target) embedded in an amorphous matrix. Depending on the elemental composition, hardness and Young's modulus of the coatings were 16–26 GPa and 155–268 GPa, respectively. The coatings are characterized by high thermal stability and oxidation resistance at temperatures up to 800 °C. Tribological tests demonstrated the decrease of the coefficient of friction (CoF) of the coatings with increasing temperature: from 0.38 (25 °C) to 0.28 (600 °C) and 0.23 (800 °C). The low wear rate and CoF of the Si-Ta-C-N coatings at elevated temperatures are explained by the formation of a thin (~100 nm) oxide layer and TaSixOy microfibers on the coating surfaces.
KW - Coating structure
KW - Composite powders
KW - High-temperature tribology
KW - Magnetron sputtering
KW - Multicomponent targets
UR - http://www.scopus.com/inward/record.url?scp=85059156826&partnerID=8YFLogxK
U2 - 10.1016/j.surfcoat.2018.12.030
DO - 10.1016/j.surfcoat.2018.12.030
M3 - Article
AN - SCOPUS:85059156826
SN - 0257-8972
VL - 359
SP - 342
EP - 353
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
ER -