Hard yet Tough Nanocomposite Coatings – Present Status and Future Trends

Zhang, Sam; Wang, Hui Li; Ong, Soon-Eng; Sun, Deen; Bui, X.L.

doi:10.1002/ppap.200600179

Cited by 119 publications

(58 citation statements)

References 79 publications

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“…[20][21][22] However, these approaches, which are based on methods applied to bulk materials, raise significant problems in coatings. 23 The slow progress in obtaining hard, yet tough, ceramic coatings is due to the relatively primitive state of the present understanding of thin film toughness, with only a small number of studies dedicated to the electronic origin of brittleness vs. ductility. 24,25 Recently, Sangiovanni et al, 26,27 using ab initio density functional theory (DFT), predicted enhanced toughness in pseudobinary B1-NaCl structure TM nitride alloys of TiN or VN and MoN or WN with Cu-Pt ordering on the cation sublattice.…”

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confidence: 99%

Toughness enhancement in hard ceramic thin films by alloy design

Kindlund¹,

Sangiovanni²,

et al. 2013

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Hardness is an essential property for a wide range of applications. However, hardness alone, typically accompanied by brittleness, is not sufficient to prevent failure in ceramic films exposed to high stresses. Using VN as a model system, we demonstrate with experiment and density functional theory (DFT) that refractory VMoN alloys exhibit not only enhanced hardness, but dramatically increased ductility. V0.5Mo0.5N hardness is 25% higher than that of VN. In addition, while nanoindented VN, as well as TiN reference samples, suffer from severe cracking typical of brittle ceramics, V0.5Mo0.5N films do not crack. Instead, they exhibit material pile-up around nanoindents, characteristic of plastic flow in ductile materials. Moreover, the wear resistance of V0.5Mo0.5N is considerably higher than that of VN. DFT results show that tuning the occupancy of d–t2g metallic bonding states in VMoN facilitates dislocation glide, and hence enhances toughness, via the formation of stronger metal/metal bonds along the slip direction and weaker metal/N bonds across the slip plane

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mentioning

confidence: 99%

Toughness enhancement in hard ceramic thin films by alloy design

Kindlund¹,

Sangiovanni²,

et al. 2013

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“…Extraordinary hardening (hardness > 40 GPa) of the thin film coatings can be attained by synthesizing nanocomposite structures which consist of nanograins surrounded by extremely thin amorphous matrix with typical thickness of 3-5 nm [70] that can successfully protect the movements of grain boundaries during deformation and thereby increased the hardness [71]. Moreover, the hardness of materials is affected by compressive residual stress [72].…”

Section: Discussionmentioning

confidence: 99%

“…With infusion of Si, Al or Ti into CrN, the grain size within the material has been found to reduce to a nanoscale that results in an increase in hardness of the coating [20]. At nanoscale grains, the formation of dislocations becomes tough and the hardness of the coatings can be controlled by changing the grains size [21]. Recently, a high resolution transmission electron microscopy (HRTEM) study showed that Cr 1-x M x N coatings consist of nanocrystalline grains surrounded by amorphous boundaries [22].…”

Section: Introductionmentioning

confidence: 99%

Near-edge X-ray absorption fine structure studies of Cr1−xMxN coatings

Rahman

Duan

Jiang

et al. 2013

Journal of Alloys and Compounds

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Near-edge X-ray absorption fine structure studies of Cr 1-x M x N coatings, (2013), doi: http://dx.doi.org/10. 1016/ j.jallcom.2013.06.021 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. AbstractCr 1-x M x N coatings, with doping concentrations (Si or Al) varying from 14.3 to 28.5 at.%, were prepared on AISI M2 tool steel substrates using a TEER UDP 650/4 closed field unbalanced magnetron sputtering system. Near-edge X-ray absorption fine structure (NEXAFS) characterization was carried out to measure the aluminum and silicon Kedges, as well as chromium L-edge, in the coatings. Two soft X-ray techniques, Auger electron yield (AEY) and total fluorescence yield (TFY), were employed to investigate the surface and inner structural properties of the materials in order to understand the structural evolution of CrN matrix with addition of Al (or Si) elements. Investigations on the local bonding states and grain boundaries of the coatings, using NEXAFS technique, provide significant information which facilitates understanding of the local electronic 2 structure of the atoms and shed light on the origins of the high mechanical strength and oxidation resistance of these technologically important coatings.

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“…Ее механизм может быть обуслов-лен как диссипацией полей напряжения в пластичной фазе, так и разрушением в поле напряжений перемычек (стяжек вязкой фазы) в мостовой структуре [9,10]. Полученные результаты дают основание утверждать, что определяющим фактором высокой твердости керамико-металлических покрытий является их нанозеренная структура, а не сжимающие макронапряжения.…”

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Высокотвердые Наноструктурные Керамико-Металлические Покрытия С Низким Уровнем Макронапряжений

Блинков¹,

Волхонский²,

Белов³

et al. 2018

Письма В Журнал Технической Физики

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The macrostressed state of (Ti,Al)N–Cu and (Ti,Al)N–Ni ceramic–metal coatings obtained by the arc-PVD method has been studied using X-ray diffraction and by measuring the radius of curvature of a coating–base composite sample (Stoney’s method). It is established that the presence of a tough metal phase favors significant reduction in the level of macrostresses in these structures as compared to those in (Ti,Al)N ceramic coatings, the absolute values of which decrease from 4.7–4.3 to 0.17–0.32 GPa. At the same time, both Ti–Al–Cu–N and Ti–Al–Ni–N coatings retain high hardness of 43 and 51 GPa, respectively, versus 29 GPa for Ti–Al–N coatings. The obtained results give grounds to suppose that the high hardness of the ceramic–metal coatings studied is determined by their nanocrystalline structure rather than by compressive macrostresses.

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Hard yet Tough Nanocomposite Coatings – Present Status and Future Trends

Cited by 119 publications

References 79 publications

Toughness enhancement in hard ceramic thin films by alloy design

Toughness enhancement in hard ceramic thin films by alloy design

Near-edge X-ray absorption fine structure studies of Cr1−xMxN coatings

Высокотвердые Наноструктурные Керамико-Металлические Покрытия С Низким Уровнем Макронапряжений

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