Surface Engineering of 316L Stainless Steel Using Duplex CrN/TiN Coatings via DC Magnetron Sputtering: Microstructural, Tribological, and Hardness Evaluation

Surface engineering plays a critical role in improving wear resistance,
corrosion resistance, and overall service life of industrial components.
This study presents the deposition and characterization of duplex
chromium nitride/titanium nitride (CrN/TiN) coatings on AISI 316L
stainless steel substrates using physical vapor deposition (PVD) via
DC magnetron sputtering. Substrate temperature, working pressure,
and nitrogen gas flow rate were selected as primary control variables,
identified from literature review and response surface methodology
(RSM) considerations. Coatings of approximately 4 μm thickness were
deposited and examined using X-ray diffraction (XRD), scanning
electron microscopy (SEM), and tribological testing according to ASTM
G99 standards. XRD analysis confirmed distinct CrN and TiN phases,
while SEM micrographs revealed uniform coating coverage with good
adhesion and minimal porosity. Wear testing demonstrated that
duplex CrN/TiN coatings significantly outperformed both uncoated
and single-layer TiN-coated samples, showing reduced wear rates and
lower coefficients of friction even under increased normal loads.
Hardness measurements indicated that duplex coatings possessed
hardness values nearly five times greater than the base 316L
substrate. These improvements are attributed to the synergistic
combination of TiN’s lubricity and CrN’s high hardness and corrosion
resistance. The findings suggest that duplex CrN/TiN coatings are
highly promising for applications requiring enhanced durability, such
as plastic molding tools, die-casting dies, and mechanical
components subject to severe wear.