Deformation and Cracking Mechanism in CrN/TiN Multilayer Coatings

Abstract

In this study, the effects of the microstructural properties on the deformation and damage mechanism of CrN/TiN multilayer coatings deposited on Custom 450 steel using the unbalanced reactive magnetron sputtering PVD process were studied. All coatings were fabricated with an overall thickness of 1.5 µm, but different bilayer periods (Λ). Structural and mechanical properties of coatings were investigated by XRD analysis and nanoindentation experiment, respectively. Indentation tests at three loads of 100, 300, and 450 mN were performed on the coatings’ surface and then, cross-sections of fractured imprints were analyzed with SEM and TEM. Measuring the length of the cracks induced by indentation loads and analyzing the load-displacement curves, apparent fracture energy values of multilayer coatings were calculated. We observed that multilayer systems with bilayer periods of 4.5–15 nm possess superlattice structure, which also results in higher values for Young’s modulus and hardness as well as higher fracture energy. Comparison of cross-sectional SEM and TEM observations showed that coatings with smaller bilayer periods tend to deform by shear sliding mechanism due to the existence of the long-grown columns, while short dispersed grains—growing in the coatings with a larger bilayer period—led to deformation via local grain boundary sliding and grain rotation.

Resistance of PVD Coatings to Erosive and Wear Processes: A Review

“…Coatings of high hardness are mainly used 2 of 34 for anti-wear applications, as protective coatings for tools and knives [13,14], and for anti-erosion applications [15][16][17]. For that reason, resistance to sliding wear [10,18], tribological properties [19], fracture toughness [16,20], fatigue toughness [6,21], solid particle erosion resistance [22,23] as well as cavitation erosion resistance [24,25] have been deeply investigated. Endurance properties of PVD coatings depend on their hardness, elastic modulus, adhesion, residual stresses and structure [26][27][28].…”

Effects of Stoichiometry on Structural, Morphological and Nanomechanical Properties of Bi2Se3 Thin Films Deposited on InP(111) Substrates by Pulsed Laser Deposition

“…Nanoindentation is a versatile technique ubiquitously used to obtain the basic mechanical parameters, such as the hardness and elastic modulus, as well as to delineate the deformation mechanisms, creep and fracture behaviors of various nanostructured materials [15][16][17][18] and thin films [19][20][21][22][23] with very high sensitivity and excellent resolution. On the other hand, wettability is an important property of a solid surface, which is intimately related to the chemical compositions and morphology of the surface [24].…”

Effects of Deposition Time on Surface Properties of Co Ni Fe Alloy Synthesised on Hex Bolts

“…The high number of voids also found in sample with the longest deposition time which reported by N. A. Resali et al [12]. The voids created weak spots where the grain able to slides freely along the median plane [13]. The cracks propagated along the plane when it reached its limit of tensile stress.…”