Chemical vapor deposition of TiN on a CoCrFeNi multi-principal element alloy substrate
Journal article, 2020

The reactivity of a quaternary multi-principal element alloy (MPEA), CoCrFeNi, as a substrate in thermal halide chemical vapor deposition (CVD) processes for titanium nitride (TiN) coatings was studied. The coatings were deposited at 850 °C–950 °C using TiCl4, H2 and N2 precursors. The coating microstructures were characterized using X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM/TEM) with energy dispersive X-ray spectroscopy (EDS). Thermodynamic calculations of substrate and coating stability for a gas phase environment of N2 and H2 within a temperature range relevant for the experiments showed that Cr is expected to form hexagonal Cr2N and cubic (Ti1−ε1Crε1)N or (Cr1−ε2Tiε2)N phases. These phases could however not be discerned in the samples by XRD after the depositions. Cr was detected at the grain boundaries and the top surface by EDS for a sample synthesized at 950 °C. Grain boundary and surface diffusion, respectively, were the suggested mechanisms for Cr transport into the coating and onto the top surface. Although thermodynamic calculations indicated that Cr is the most easily etched component of the CoCrFeNi alloy to form gaseous chlorides in similar concentrations to that of the residual Ti-chlorides, no sign of etching were found according to the imaging of the sample cross-sections using SEM and TEM. Cross-section and top surface images further confirmed that the choice of substrate had no significant detrimental influence on the film growth or microstructure.

transmission electron microscopy

Titanium nitride

chemical vapour deposition

X-ray diffraction

multi-principle element alloy

Calphad

Author

Katalin Böör

Uppsala University

Ren Qiu

Chalmers, Physics, Microstructure Physics

Axel Forslund

Royal Institute of Technology (KTH)

Olof Bäcke

Chalmers, Physics, Microstructure Physics

Henrik Larsson

Royal Institute of Technology (KTH)

Erik Lindahl

AB Sandvik Coromant

Mats Halvarsson

Chalmers, Physics, Microstructure Physics

Mats Boman

Uppsala University

L. von Fieandt

AB Sandvik Coromant

Surface and Coatings Technology

0257-8972 (ISSN)

Vol. 393 125778

CVD 2.0 - En ny generation av hårda beläggningar

Swedish Foundation for Strategic Research (SSF), 2016-05-01 -- 2021-06-30.

Subject Categories

Inorganic Chemistry

Metallurgy and Metallic Materials

Other Electrical Engineering, Electronic Engineering, Information Engineering

Areas of Advance

Production

Materials Science

Roots

Basic sciences

Driving Forces

Innovation and entrepreneurship

Learning and teaching

Pedagogical work

DOI

10.1016/j.surfcoat.2020.125778

More information

Latest update

8/28/2020