Deposition of α-Al2O3 hard coatings by reactive magnetron sputtering

Kohara, Takahiro; Tamagaki, Hiroshi; Ikari, Yoshimitu; Fujii, Hideo

doi:10.1016/j.surfcoat.2003.11.017

Cited by 105 publications

(57 citation statements)

References 10 publications

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“…Fig.3c, Fig.3d show that a new peak has risen at 74.4 eV originated from Al-O in the Al 2p XPS spectra of the sputtered pressboard surface. As reported in [15], the binding energy of O-Al 531.2 eV shown in O 1s spectra and the binding energy of Al-O 74.4 eV shown in Al 2p spectra are attributed to A12O3. The binding energy difference between Al 2p and O 1s is 458 eV for samples sputtered 60 min, which is similar to literature [15].…”

Section: B Xps Analysissupporting

confidence: 68%

“…As reported in [15], the binding energy of O-Al 531.2 eV shown in O 1s spectra and the binding energy of Al-O 74.4 eV shown in Al 2p spectra are attributed to A12O3. The binding energy difference between Al 2p and O 1s is 458 eV for samples sputtered 60 min, which is similar to literature [15]. According to XPS analysis results, the atomic content ratio of Al/O is 0.65, which is close to the stoichiometric composition of Al 2 O 3 (Al/O=0.66) [15].…”

Section: B Xps Analysissupporting

confidence: 68%

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Structure and Space Charge Inhibition Performance of Reactive RF Magnetron Sputter Deposited Al2O3 Thin Film on the Fiber Surface

Hao¹,

Li²,

Liao³

et al. 2018

Proceedings of the 4th Annual International Conference on Material Engineering and Application (ICMEA 2017)

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Abstract-Cellulose insulation paper/pressboard has been widely used in HVDC transformers. In this study, the aluminum oxide function film was deposited on the cellulose insulation pressboard surface using reactive radio frequency (RF) magnetron sputtering. The sputtered thin film was characterized by the scanning electron microscopy (SEM) and the X-ray photoelectron spectroscopy (XPS). The influence of the deposited function film on the space charge injection/accumulation behavior was investigated. SEM and XPS results show that the nano-structured Al 2 O 3 film was successfully fabricated on the fiber surface. The oil impregnated sputtered pressboard presents apparent space charge suppression effect. The obtained band gap energy (Eg) of Al 2 O 3 is 7.39 eV. The nano-structured Al 2 O 3 film introduces a new trap band which is helpful for the charge inhibition.

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Section: B Xps Analysissupporting

confidence: 68%

Section: B Xps Analysissupporting

confidence: 68%

Structure and Space Charge Inhibition Performance of Reactive RF Magnetron Sputter Deposited Al2O3 Thin Film on the Fiber Surface

Hao¹,

Li²,

Liao³

et al. 2018

Proceedings of the 4th Annual International Conference on Material Engineering and Application (ICMEA 2017)

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“…Unfortunately, the consistence of droplets embedded in thin TEM lamella leads to difficulties which prevent further detailed investigations on the interface between the droplet surface and the ongrowing hexagonal crystallites. According to electron energy loss-spectroscopy, we can conclude that α-Cr2O3 and Fe2O3 locally formed at the particles give rise for subsequent facilitated hexagonal growth of (Al,Cr,Fe)2O3, similar to the process which was observed for the template supported growth of hexagonal Al2O3 and (Al,Cr)2O3 growth [6][7][8]. In addition, Zhang et al [17] studied the formation of a thermally-grown α-Al2O3 scale on Al8Cr5.…”

Section: Resultsmentioning

confidence: 65%

“…In particular, the thermodynamically stable corundum or α phase exhibits the most interesting properties of all Al2O3 polymorphs. Low temperature physical vapour deposition (PVD) of Al2O3 films, however, often yields in the formation of a significant volume fraction of amorphous-like and metastable phases [5,6]. Consequently, these coatings are susceptible to thermally-induced transformation into the stable corundum structure, initiating the formation of crack networks and stresses, which can ultimately lead to failure of the coating.…”

Section: Introductionmentioning

confidence: 99%

Triggering the Phase Evolution Within (Al,Cr)2O3-based Coatings by Alloying and Microstructural Concepts

Koller

Hahn

Widrig

et al. 2016

Berg Huettenmaenn Monatsh

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Abstract:The synthesis of (Al,Cr)2O3 coatings by PVD frequently results in metastable cubic structures next to the thermodynamically stable and mechanically favourable hexagonal corundum phase. By alloying small amounts of Fe to powder-metallurgically produced Al0.7Cr0.3 targets -used to synthesise (Al,Cr)2O3 films by cathodic arc evaporation -a considerable increase of the hexagonal phase fraction is observed. Detailed transmission electron microscopy studies show that the growth of hexagonal crystallites of a solid solution (Al,Cr,Fe)2O3 can be triggered by small Cr-and Fe-enriched spherical particles, so-called droplets. In contrast, larger spherical or flat-shaped Alrich droplets induce re-nucleation of undesired cubic film growth. Extending these studies to additional (Al,Cr)2O3 coating systems revealed similar mechanisms, albeit by far less frequent than in the case of Fe-alloyed films. Modifications of the chemical composition of the target by small amounts of dopants may reduce droplet generation and contribute to controlled coating nucleation. Therefore, the cathode surface used is compared with particles, intentionally selected from the plasma stream. Keywords

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“…For this and other reasons research and development on PVD alumina by, for instance, dual magnetron sputtering [3], and arc evaporation [4] has been intense for the past few years. Preoxidation of Cr-containing surfaces have enabled nucleation and growth of α-alumina [5], but still requires substrate temperatures of 700-750ºC. A commercial technology capable of growing highly crystalline mixed oxides (Al,Cr) 2 O 3 by the arc method at temperatures below 600ºC were recently made available on the market [6], but the commercialization of pure PVD α-alumina still remains.…”

Section: Introductionmentioning

confidence: 99%

α-Alumina coatings on WC/Co substrates by physical vapor deposition

Selinder

Coronel

Wallin

et al. 2009

International Journal of Refractory Metals and Hard Materials

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Physical vapor deposition coatings for cutting tools may be deposited by, e.g. reactive magnetron sputtering. Alumina growth in Ar/O 2 gas mixtures gives rise to problems due to insulating layers on targets, and hysteresis effects with respect to oxygen gas flow. In this paper is described a technology for the deposition of crystalline alumina: reactive high power impulse magnetron sputtering. Pure Al was used as target material, and the cemented carbide (WC/Co) substrates were kept at 500-650ºC. Hysteresis effects with respect to oxygen gas flow were alleviated, which enabled stable growth at a high deposition rate. The high power impulses were helpful in obtaining a crystalline oxide coating. X-ray diffraction and cross-section transmission electron microscopy showed that α-alumina films were formed. Technological testing of these PVD alumina coatings, with state-of-the-art AlTiN as benchmark, showed significantly improved crater wear resistance in steel turning.

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Deposition of α-Al2O3 hard coatings by reactive magnetron sputtering

Cited by 105 publications

References 10 publications

Structure and Space Charge Inhibition Performance of Reactive RF Magnetron Sputter Deposited Al2O3 Thin Film on the Fiber Surface

Structure and Space Charge Inhibition Performance of Reactive RF Magnetron Sputter Deposited Al2O3 Thin Film on the Fiber Surface

Triggering the Phase Evolution Within (Al,Cr)2O3-based Coatings by Alloying and Microstructural Concepts

α-Alumina coatings on WC/Co substrates by physical vapor deposition

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