Toughness Enhancement in TiN/WN Superlattice Thin Films

Buchinger, Julian; Koutná, Nikola; Chen, Zhuo; Zhang, Zaoli; Mayrhofer, Paul H.; Holec, David; Bartosik, Matthias

doi:10.2139/ssrn.3358867

Cited by 6 publications

(11 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This led to the development of nanoscale composites [44,66,67]. Existing literature based on this approach includes the incorporation of ductile phases into the ceramic matrix to hinder crack propagation [46,[68][69][70][71], ductile phases at nanocolumn boundaries [72], multilayer and nanocomposite structures to control crack propagation by deflection [63,[73][74][75][76][77][78][79][80][81], phase transformations [82][83][84][85], and carbon-nanotubes [86][87][88]. Other toughening methods include the introduction of compressive stresses to inhibit crack growth [63,[89][90][91], hierarchical nano/microstructures [92], crack deflection toughening using tilted interfaces [93], and grainboundary sliding [52,94,95].…”

Section: Introductionmentioning

confidence: 99%

A review of the intrinsic ductility and toughness of hard transition-metal nitride alloy thin films

et al. 2019

View full text Add to dashboard Cite

Over the past decades, enormous effort has been dedicated to enhancing the hardness of refractory ceramic materials. Typically, however, an increase in hardness is accompanied by an increase in brittleness, which can result in intergranular decohesion when materials are exposed to high stresses. In order to avoid brittle failure, in addition to providing high strength, films should also be ductile, i.e., tough. However, fundamental progress in obtaining hard-yet-ductile ceramics has been slow since most toughening approaches are based on empirical trial-and-error methods focusing on increasing the strength and ductility extrinsically, with a limited focus on understanding thin-film toughness as an inherent physical property of the material. Thus, electronic structure investigations focusing on the origins of ductility vs. brittleness are essential in understanding the physics behind obtaining both high strength and high plastic strain in ceramics films. Here, we review recent progress in experimental validation of density functional theory predictions on toughness enhancement in hard ceramic films, by increasing the valence electron concentration, using examples from the V1-xWxN and V1-xMoxN alloy systems.

show abstract

Section: Introductionmentioning

confidence: 99%

A review of the intrinsic ductility and toughness of hard transition-metal nitride alloy thin films

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The MoN/TaN SL system studied here is an interesting model system as it essentially allows us to study the effect of largely different lattice parameters at comparably similar shear moduli (the difference in G is below 32 GPa). For comparison, ΔG for other well-studied SL systems is easily between~50 and 90 GPa 17,[35][36][37] . The average grain size of our MoN/TaN superlattices also shows no strong dependence on the bilayer period, contrary to other material combinations.…”

Section: Discussionmentioning

confidence: 99%

“…In particular, the input elastic constants correspond to the equilibrium lattice parameters of each individual phase, which do not properly represent the stress state of the material in the SL. To provide a more realistic picture of the interface, the original formalism was extended to a generally n layers forming the SL in question 35 . The interface effects were modeled by setting the elastic constants of one of the n layer materials to those of a chosen superlattice with a small bilayer period.…”

Section: Methodsmentioning

confidence: 99%

Mechanistic study of superlattice-enabled high toughness and hardness in MoN/TaN coatings

et al. 2020

Self Cite

View full text Add to dashboard Cite

Machining and forming tools exposed to challenging environments require protective coatings to extend their lifetime and reliability. Although transition metal nitrides possess excellent strength and resistance against chemical attacks, they lack ductility and are prone to premature failure. Here, by investigating structural and mechanical properties of MoN-TaN superlattices with different bilayer thickness, we develop coatings with high fracture toughness and hardness, stemming from the formation of a metastable tetragonally distorted phase of TaN up to layer thicknesses of 2.5 nm. Density functional theory calculations and experimental results further reveal a metal-vacancy stabilized cubic Ta 0.75 N phase with an increased Young's modulus but significantly lower fracture toughness. We further discuss the influence of coherency strains on the fracture properties of superlattice thin films. The close interplay between our experimental and ab initio data demonstrates the impact of phase formation and stabilization on the mechanical properties of MoN-TaN superlattices.

show abstract

“…vanadium carbonitride (VCN) and titanium tungsten carbonitride (TiWCN). Hardness and fracture toughness were enhanced by nanoscale multilayer architectures [16,17]. Addition of tungsten to the conventional ternary coating has been found to increase toughness without compromising hardness [18].…”

Section: Methodsmentioning

confidence: 99%

An investigation into the behaviour of selected boundary regime lubricants when cold forging steel under rolling-sliding conditions

Fleming

2021

Tribology International

View full text Add to dashboard Cite

Toughness Enhancement in TiN/WN Superlattice Thin Films

Cited by 6 publications

References 32 publications

A review of the intrinsic ductility and toughness of hard transition-metal nitride alloy thin films

A review of the intrinsic ductility and toughness of hard transition-metal nitride alloy thin films

Mechanistic study of superlattice-enabled high toughness and hardness in MoN/TaN coatings

An investigation into the behaviour of selected boundary regime lubricants when cold forging steel under rolling-sliding conditions

Contact Info

Product

Resources

About