Abstract

The aim of the study is to extend the NbN coating on MS with Nb interlayer to explore the benefits of hard nitride coatings on low-cost structural material and to compare the coating with NbN monolithic coating on SS. NbN on MS and SS was deposited by reactive d.c. magnetron sputtering at various N2/Ar flow ratios and substrate bias. Deposition rate decreased from 20 to 10 nm/min (without biasing) and from 16 to 8 nm/min (−50 V biasing) when ratio was varied from zero to 70%. Deposition rate decreased with the increase in bias voltage. Coatings showed hexagonalβNb2N, cubicδNbN, and hexagonalδ′ NbN as major phases with the increasing N2flow. Surface hardness reached a maximum of 2040 HK25at a of 20%. Critical loads, for cohesive and adhesive failure for coating on MS, were between 6–8 N and 9–12 N respectively; for coating on SS, the values were between 7–15 N and 12–25 N respectively. Duplex coatings were studied for hardness by Knoop microindentation, adhesion by scratch tester, and corrosion by potentiodynamic polarization technique. Hardness, adhesion, and corrosion resistance all improved when NbN coating was incorporated with Nb interlayer on MS.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.