Microstructure and multifunctional properties of Ti–Si–B–C coatings by plasma-enhanced chemical vapour deposition

Abstract

Hard coatings are required to have a long lifetime without performance degradation when used in tough working environments. In this study, quaternary Ti–Si–B–C coatings with various Si contents were synthesised at a relatively low temperature of 600°C by a plasma-enhanced chemical vapour deposition. Effect of the Si/(Si+B) ratio on the microstructure and mechanical properties of the Ti–Si–B–C coatings was systematically investigated. Instrumental analyses, such as EPMA, XRD, XPS and HR-TEM, revealed that the microstructure was changed from a huge crystalline structure with an hexagonal close-packed (HCP) (Ti,C)B₂ phase into a nanocomposite structure that consists of nano-sized HCP (Ti,C)B₂ crystallites and amorphous SiC/TiC phases by a percolation effect with the Si addition. As the Si content increased, hardness of the Ti–Si–B–C coatings varied from 18.8 to 35.6 GPa. In addition, the tribology and anti-oxidation properties of the Ti–Si–B–C coatings with the characteristic microstructural evolution were fairy improved compared with Ti–B–C coatings. The Ti–Si–B–C coatings had excellent multifunctional properties, including high hardness, low friction coefficient and high temperature oxidation resistance.

Keywords:

• Ti–Si–B–C
• Nanocomposite
• PECVD
• Multifunction

ORCID

J. H. Shin http://orcid.org/0000-0003-0271-9329

Additional information

Funding

This work was supported by a 2-Year Research Grant of Pusan National University, Korea.