Recent progress in the superhard nanocrystalline composites: towards their industrialization and understanding of the origin of the superhardness

Vepřek, S.; Nesládek, Pavel; Niederhofer, A.; Glatz, F.; Jílek, Mojmír; Šı́ma, M.

doi:10.1016/s0257-8972(98)00618-5

Cited by 239 publications

(104 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Chung et al 2012). Veprek et al 1998) contributed the increase in hardness of Ti-Si-N films with increase in Si content up to an optimal point followed by a decrease in the grain size. In this work, it was shown that the incorporation of large grain size c-Si into amorphous TiN matrix in the form of isolated nanocrystalline Si phases in the Ti-Si-N film with Si content of 20 at.…”

Section: Figure 3 Evolution Of C-si and Tin Grain Sizes Of Ti-si-n mentioning

confidence: 95%

Microstructure and mechanical properties of magnetron sputtered Ti-Si-N coatings with different silicon content

Dergham¹,

Chekour²,

Khen³

2017

MJS

View full text Add to dashboard Cite

This work deals with the deposition and characterization of (Ti-Si-N) coatings. A series of Ti-Si-N thin films with different silicon content were deposited on Si (100) substrate by RF magnetron sputtering in an Ar-N 2 gas mixture. The influence of Si content on the microstructural and mechanical properties of the as deposited. The as deposited films were studied by using different characterization techniques such as SEM equipped with Energy Dispersive X-ray spectroscopy (EDS) for determining the composition of the films, XRD was used to determine microstructural composition and nano-indentation with MTS XP system for mechanical properties. Scherer's formula was used to determine the grain size, from the full width at half maximum of (111) experimental peaks, residual stresses of the films were measured by an optical interference apparatus using Newton's ring method Results reveal that the film deposited with Si content of 20 at. % has a dense nanostructure and the surface morphology of the Ti-Si-N coatings show neither holes nor column headings. The film deposited with Si content of 33 at. % shows a surface morphology of damaged surface. The X-ray spectra show that Ti-Si-N coatings deposited with Si content of 0 at.%, 27 at.%, 33 at.%, 40 at.% possess a preferential orientation in the direction of (111) and this orientation peak disappears for films with low of Si content. The residual stress built in the coating is compressive and they increase with increase in Si content and reach a maximum of 2.22 GPa. The hardness of the Ti-Si-N films also increases to a maximum with increase in Si content beyond which further addition of the Si decrease the hardness. The TiN grain size as calculated from the XRD diffraction peak decreases with increase in the Si content to saturation value of around 12.8nm for films without addition of silicon to 3.8nm for films with 40at. % of Si

show abstract

Section: Figure 3 Evolution Of C-si and Tin Grain Sizes Of Ti-si-n mentioning

confidence: 95%

Microstructure and mechanical properties of magnetron sputtered Ti-Si-N coatings with different silicon content

Dergham¹,

Chekour²,

Khen³

2017

MJS

View full text Add to dashboard Cite

show abstract

“…Such nano-crystalline ceramics are the focus of intense research as they have the potential for unique properties such as "super hardness" and significantly high toughness [118][119][120][121].…”

Section: Fabricating Nanocrystalline Ceramics Using Pipmentioning

confidence: 99%

“…The superior properties of nanocrystalline ceramics are governed primarily by the crystal structure [119,121,125]. There have been attempts to simulate the atomic structure and understand the materials properties of PDCs at fundamental level by modeling and computational studies [126][127][128][129], but these studies have not addressed the unique properties that are sometimes observed in these materials.…”

Section: Fabricating Nanocrystalline Ceramics Using Pipmentioning

confidence: 99%

Novel Processing of Unique Ceramic-Based Nuclear Materials and Fuels

Zhang¹,

Singh²

2008

View full text Add to dashboard Cite

Advances in nuclear reactor technology and the use of gas-cooled fast reactors require the development of new materials that can operate at the higher temperatures expected in these systems. These include refractory alloys based on Nb, Zr, Ta, Mo, W, and Re; ceramics and composites such as those based on silicon carbide (SiC f -SiC); carbon-carbon composites; and advanced coatings. Besides the ability to handle higher expected temperatures, effective heat transfer between reactor components is necessary for improved efficiency. Improving thermal conductivity of the materials used in nuclear fuels and other temperature critical components can lower the center-line fuel temperature and thereby enhance durability and reduce the risk of premature failure.Silicon carbide (SiC) is an important ceramic, most commonly used because of its excellent properties such as high strength, high modulus, excellent creep resistance and its high temperature stability. Moreover, crystalline silicon carbide is attracting wide attention as a promising candidate for several applications in nuclear reactors owing to its high thermal conductivity, high melting temperature, good chemical stability, and resistance to swelling under heavy ion bombardment. There have been many efforts to develop SiC based composites in various forms for use in advanced energy systems. However, fabricating SiC based composites by traditional powder processing route generally requires very high temperatures for pressureless sintering. In recent years, with the development of high yield preceramic precursors, the polymer infiltration and pyrolysis (PIP) method has aroused interest for the fabrication of ceramic based materials. Polymer derived ceramic materials offer unique advantages such as ability to fabricate net shaped components, incorporate reinforcements, along with lower processing temperatures, and perhaps most importantly relatively easy control over the microstructure. The raw materials are element-organic polymers whose composition and architecture can be tailored and varied.The primary focus of this work is to use a pyrolysis-based process to fabricate a host of novel silicon carbide-metal carbide/oxide composites, and to synthesize new materials based on mixed-metal (metal/silicon) carbides that cannot be processed using conventional techniques. These mixedcarbide material systems are expected to offer improved material properties for higher-temperature applications. Our fabrication technique resulted in both amorphous and nano-grained SiC matrix composites by controlled pyrolysis of allylhydridopolycarbosilane (AHPCS), the precursor for SiC for our study, under inert argon atmosphere.Cylindrical pellets, φ25 × 25 mm, were fabricated for bulk scale characterization. These samples were analyzed in terms of density and porosity, thermal conductivity, and flexural strength under multiaxial loading conditions. The final composition in the fabricated composite was studied use Xray diffraction (XRD). This was useful in understanding the relative stabil...

show abstract

“…Идеи создания высокопрочных нанокристаллических материалов, основанные на представлениях [73][74][75] о подавлении процессов роста зародышевых трещин, генерации и распространения дисло-каций при уменьшении размеров кристаллитов до значений едини-цы и десятки нанометров, в настоящее время нашли эффективное использование при создании покрытий [76][77][78][79][80][81][82][83][84][85][86][87]. В результате за по-следние 10 лет были разработаны сверхтвердые (Н   40 ГПа) нано-композитные покрытия типа nMeN-а фаза (аморфные фазы Si 3 N 4 , BN, TiB 2 , Me-Ti, W, Zr, V) [76][77][78][79][80][81] и nMeN-металл (nMeN -нанок-ристаллические нитриды сплавов Ti, Zr, С, V, W; металл -Cu, Y, Ni) [82][83][84][85][86][87].…”

Section: сверхтвердые нанокристаллические покрытияunclassified

Structure, Properties and Fabrication of the Solid Nanocrystalline Coatings Deposited in Several Ways

Beresnev¹,

Pogrebnyak

Azarenkov

et al. 2007

Usp. Fiz. Met.

View full text Add to dashboard Cite

Recent progress in the superhard nanocrystalline composites: towards their industrialization and understanding of the origin of the superhardness

Cited by 239 publications

References 67 publications

Microstructure and mechanical properties of magnetron sputtered Ti-Si-N coatings with different silicon content

Microstructure and mechanical properties of magnetron sputtered Ti-Si-N coatings with different silicon content

Novel Processing of Unique Ceramic-Based Nuclear Materials and Fuels

Structure, Properties and Fabrication of the Solid Nanocrystalline Coatings Deposited in Several Ways

Contact Info

Product

Resources

About