High temperature tribology of polymer derived ceramic composite coatings

Sajid Ali Alvi,Farid Akhtar

doi:10.1038/s41598-018-33441-8

Abstract

Polymer derived ceramic (PDC) composite coatings were deposited on AISI 304 substrates using siloxane based preceramic polymer polymethlysilsquioxane (PMS) and ZrSi2 as active filler or Ag as passive filler. The tribological performance of the composite coatings was evaluated at room temperature and moderately high temperatures (150 °C, 200 °C, 300 °C and 400 °C). The composite coatings showed low coefficient of friction (COF), µ, from 0.08 to 0.2 for SiOC-ZrSi2 composite coatings, and from 0.02 to 0.3 for SiOC-Ag composite coatings, at room temperature with increasing normal load from 1 to 5 N. High temperature tribology tests showed high COF values from 0.4 to 1 but low wear for SiOC-ZrSi2 coating, and low COF from 0.2 to 0.3 for SiOC-Ag coatings at lower temperature ranges. Low load friction tests at room temperature showed negligible wear in SiOC-ZrSi2 coatings, suggesting good wear resistant and lubricating properties due to formation of t-ZrO2 and carbon. Low COF and high amount of wear was observed in SiOC-Ag composite coatings at room temperature due to high ductility of Ag and smearing of wear debris in the wear track. The coatings and wear tracks were characterized to evaluate the lubrication and wear behavior.

Highlights

There is an ongoing demand for high temperature tribological coatings in different industries, such as coatings in aerospace and automobile, with tailored properties, such as high hardness, better friction and wear properties at higher temperatures, as well as oxidation and corrosion resistant properties[1,2,3]
Different additives of WS2/CaF2/h-BN has been added to Ni alloy matrix powders and laser cladded on Ti-6Al-4V substrate tested at different temperatures giving low coefficient of friction (COF) of 0.32–0.35 (25 °C), 0.27–0.3 (300 °C) and 0.21–0.29 (600 °C) and wear rate was reduced to 0.9–9 × 10−5 mm3/Nm (25 °C), 0.15–8 × 10−5 mm3/Nm (300 °C) and 2–4 × 10−5 mm3/Nm (600 °C)
Coated and subsequent in-situ formed nanocomposite of yttria-stablized zirconia (YSZ) coating containing Ag and Mo, and binary oxides of α-MoO3 and V2O5 doped with Ag or Cu showed reduced COF from ~0.7 to 0.14 due to formation of magneli phases with increasing temperature up to 700 °C9–14

Summary

OPEN High temperature tribology of polymer derived ceramic composite coatings

Polymer derived ceramic (PDC) composite coatings were deposited on AISI 304 substrates using siloxane based preceramic polymer polymethlysilsquioxane (PMS) and ZrSi2 as active filler or Ag as passive filler. Low load friction tests at room temperature showed negligible wear in SiOC-ZrSi2 coatings, suggesting good wear resistant and lubricating properties due to formation of t-ZrO2 and carbon. With its ability to grow controlled coating layers, has been explored for high temperature tribology to develop nanocrystalline ZnO (room temperature(RT); COF: ~0.1), wear resistant nanolaminates of ZnO/Al2O3/ZrO2 with a thickness of 140 nm (wear rate at 150 °C: 3.6 × 10−6 mm3/Nm; 400 °C: 3.1 × 10−5 mm3/Nm)[18,19,20]. PDC composite coatings were designed using fillers, such as ZrSi2 and Ag, which can give tribological properties at different temperatures

Results and Discussion

Methods

Additional Information