Effects of Co, Ti Interlayer, and Post-Annealing on the Adhesion Property between TiN Coatings and WC-Co Substrate

Abstract

In order to improve adhesion strength between TiN coatings and WC-Co substrate, two kinds of interlayer of Co and Ti were pre-deposited before TiN coating process. Thickness and postannealing effects of each interlayer on the adhesion property were investigated through scratch test in this work. Introduction of thin Ti interlayer largely enhanced the adhesion strength between TiN coatings and WC-Co substrate in scratch test. The critical load, Lc2 increased from 64 N without Ti interlayer up to 130N with Ti one of ~ 0.15 thickness. However, post-annealing of TiN/Ti/WCCo system at high temperature of 600 reduced the critical load again. The Ti interlayer caused a deficit of Co content in WC-Co substrate during annealing through diffusion of Co element into Ti interlayer. The reduction of critical load after post-annealing was believed due to diminution in mechanical properties of the substrate derived from the Co deficit in WC-Co substrate. On the other hand, introduction of thin Co interlayer of ~ 0.027 thickness also increased the critical load up to 84 N and improved failure mode, but did not reduce the critical load even after annealing, rather increased it. And, any Co deficit of the substrate was not found after annealing for TiN/Co/WC-Co system.

Mechanical properties and cutting performance of nanocomposite Cr–Si–N coated tool for green machining

“…An arc cathode gun for Cr source and a d.c. sputter gun for Si source were installed inside chamber depicted in previous works [5]. Purities of Cr and Si targets were 99.99% and 99.99%, respectively.…”

Arc ion plated Cr/CrN/Cr multilayers on 316L stainless steel as bipolar plates for polymer electrolyte membrane fuel cells

“…Then CrN was assigned as the underneath layer to enhance the mechanical and anti-corrosion property. Accounting for higher internal stress usually caused by the big dismatch of physical properties between hard ceramic CrN and relative soft metallic SS316L [30,31], an interlayer of Cr followed CrN layer to improve the bonding strength. So the designed coating was sandwich-like structure, i.e.…”