| 1. |
- Lauridsen, Jonas, et al.
(författare)
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Microstructure evolution of Ti-Si-C-Ag nanocomposite coatings deposited by DC magnetron sputtering
- 2010
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Ingår i: Acta Materialia. - : Elsevier Ltd.. - 1359-6454 .- 1873-2453. ; 58:20, s. 6592-6599
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Tidskriftsartikel (refereegranskat)abstract
- Nanocomposite coatings consisting of Ag and TiCx (x < 1) crystallites in a matrix of amorphous SiC were deposited by high-rate magnetron sputtering from Ti-Si-C-Ag compound targets. Different target compositions were used to achieve coatings with a Si content of similar to 13 at.%, while varying the C/Ti ratio and Ag content. Electron microscopy, helium ion microscopy, X-ray photoelectron spectroscopy and X-ray diffraction were employed to trace Ag segregation during deposition and possible decomposition of amorphous SiC. Eutectic interaction between Ag and Si is observed, and the Ag forms threading grains which coarsen with increased coating thickness. The coatings can be tailored for conductivity horizontally or vertically by controlling the shape and distribution of the Ag precipitates. Coatings were fabricated with hardness in the range 10-18 GPa and resistivity in the range 77-142 mu Omega cm.
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| 2. |
- Sarius, N. G., et al.
(författare)
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Ni and Ti diffusion barrier layers between Ti-Si-C and Ti-Si-C-Ag nanocomposite coatings and Cu-based substrates
- 2012
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Ingår i: Surface & Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 206:8-9, s. 2558-2565
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Tidskriftsartikel (refereegranskat)abstract
- Sputtered Ni and Ti layers were investigated as a diffusion barrier to substitute electroplated Ni between Ti-Si-C and Ti-Si-C-Ag nanocomposite coatings and Cu or CuSn substrates. Samples were subjected to thermal annealing studies by exposure to 400 degrees C for 11 h. Dense diffusion barrier and coating hindered Cu from diffusing to the surface. This condition was achieved for electroplated Ni in combination with magnetron-sputtered Ti-Si-C and Ti-Si-C-Ag layers deposited at 230 degrees C and 300 degrees C. and sputtered Ti or Ni layers in combination with Ti-Si-C-Ag deposited at 300 degrees C.
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| 3. |
- Bauer, A. D., et al.
(författare)
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Corrosion behaviour of monocrystalline titanium nitride
- 1997
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Ingår i: Surface and Coatings Technology. ; 91:3, s. 208-214
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Tidskriftsartikel (refereegranskat)abstract
- The corrosion behaviour of monocrystalline and highly textured TiN films deposited onto single crystalline MgO has been investigated. It was found that films with high defect concentrations and elements of polycrystallinity had a reduced corrosion resistance. These films had low corrosion potentials and high critical and passive current densities. For high quality films the [110]- and [111]-orientations generally displayed better corrosion properties than films with [100]-orientation. Corrosion had different effects on films of different orientations: On [100]-oriented films loose rectangularly shaped flakes were observed. [110]-oriented films cracked because of compressive stresses, which in many cases caused the films to peel off during corrosion. On [111]-oriented films, finally, triangular pits were detected after corrosion. Films with high corrosion potentials had low values of critical and passive current densities. Non-destructive electrochemical analysis in combination with defect analysis can thus be used to predict the behaviour of these films on anodic polarisation.
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| 4. |
- Böhlmark, Johan, et al.
(författare)
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Guiding the deposition flux in an ionized magnetron discharge
- 2006
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Ingår i: Thin Solid Films. - Amsterdam, Netherlands : Elsevier. - 0040-6090 .- 1879-2731. ; 515:4, s. 1928-1931
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Tidskriftsartikel (refereegranskat)abstract
- A study of the ability to control the deposition flux in a high power impulse magnetron sputtering discharge using an external magnetic field is presented in this article. Pulses with peak power of 1.4 kWcm-2 were applied to a conventional planar magnetron equipped with an Al target. The high power creates a high degree of ionization of the sputtered material, which opens for an opportunity to control of the energy and direction of the deposition species. An external magnetic field was created with a current carrying coil placed in front of the target. To measure the distribution of deposition material samples were placed in an array surrounding the target and the depositions were made with and without the external magnetic field. The distribution is significantly changed when the magnetic field is present. An increase of 80 % in deposition rate is observed for the sample placed in the central position (right in front of the target center) and the deposition rate is strongly decreased on samples placed to the side of the target. The measurements were also performed on a conventional direct current magnetron discharge, but no major effect of the magnetic field was observed in that case.
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| 5. |
- Eklund, Per, et al.
(författare)
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Microstructure and electrical properties of Ti-Si-C-Ag nanocomposite thin films
- 2007
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Ingår i: Surface & Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 201:14, s. 6465-6469
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Tidskriftsartikel (refereegranskat)abstract
- Ti-Si-C-Ag nanocomposite coatings consisting of nanocrystalline TiC in an amorphous Si matrix with segregated Ag were deposited by dual magnetron sputtering from Ti3SiC2 and Ag targets. As evidenced by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, for Ag contents below 10 at.%, the Ag forms similar to 10 nm large crystallites that are homogeneously distributed in the films. For higher Ag contents, coalescence during growth results in the formation of > similar to 100 nm Ag islands on the film surface. The electrical resistivity of the coatings was measured in a four-point-probe setup, and ranged from 340 mu Omega cm (for Ti-Si-C coatings without Ag) to 40 mu Omega cm (for high Ag content).
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| 6. |
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| 7. |
- Gunnarsson Sarius, Niklas, 1976-, et al.
(författare)
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Ni and Ti diffusion barrier layers between Ti-Si-C-Ag nanocomposite coatings and Cu-based substrates
- 2012
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Ingår i: Surface & Coatings Technology. - : Elsevier. - 0257-8972 .- 1879-3347. ; 206:8-9, s. 2558-2565
-
Tidskriftsartikel (refereegranskat)abstract
- Sputtered Ni and Ti layers were investigated as substitutes for electroplated Ni as adiffusion barrier between Ti-Si-C and Ti-Si-C-Ag nanocomposite coatings and Cu orCuSn substrates. Samples were subjected to thermal annealing studies by exposure to400 ºC during 11 h. Dense diffusion barrier and coating hindered Cu from diffusing tothe surface. This condition was achieved for electroplated Ni in combination withmagnetron-sputtered Ti-Si-C and Ti-Si-C-Ag layers deposited at 230 ºC and 300 ºC,and sputtered Ti or Ni layers in combination with Ti-Si-C-Ag deposited at 300 ºC.
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| 8. |
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| 9. |
- Hultman, L, et al.
(författare)
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Growth and electronic properties of epitaxial TiN thin films on 3C-SiC(001) and 6H-SiC(0001) substrates by reactive magnetron sputtering
- 1996
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Ingår i: Journal of Materials Research. - 0884-2914. ; 11:10, s. 2458-2462
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Tidskriftsartikel (refereegranskat)abstract
- Epitaxial TiN films were grown on cubic (3C)-SiC(001) and hexagonal (6H)-SiC(0001) substrates by ultrahigh vacuum reactive magnetron sputtering from a Ti target in a mixed Ar and N2 discharge at a substrate temperature of 700°C. Cross-sectional transmission electron microscopy, including high-resolution imaging, showed orientational relationships TiN(001) ∥ 3C-SiC(001), and TiN[110] ∥ 3C-SiC[110], and TiN(111) ∥ 6H-SiC(0001) and TiN[110],[101] ∥ 6H-SiC[1210]. In the latter case, twin-related TiN domains formed as the result of nucleation on SiC terraces with an inequivalent stacking sequence of Si and C. The TiN/SiC interface was locally atomically sharp for both SiC polytypes. Defects in the TiN layers consisted of threading double positioning domain boundaries in TiN(111) on 6H-SiC. Stacking faults in 3C-SiC did not propagate upon growth of TiN. Room-temperature resistivity of TiN films was ρ = 14 μΩ cm for 6H-SiC(0001) and ρ = 17 μΩ cm for 3C-SiC(001) substrates. Specific contact resistance of TiN to 6H-SiC(0001) was 1.3 × 10-3 Ω cm2 for a 6H-SiC substrate with an n-type doping of 5 × 1017 cm-3.
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| 10. |
- Karlsson, L, et al.
(författare)
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Growth, microstructure, and mechanical properties of arc evaporated TiCxN1-x (0 <= x <= 1) films
- 2000
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Ingår i: Surface & Coatings Technology. - 0257-8972 .- 1879-3347. ; 126:1
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Tidskriftsartikel (refereegranskat)abstract
- TiCxN1-x films with x ranging from 0 to 1 were grown by arc evaporation by varying the flow ratio between the reactive gases. The substrates were cemented carbide inserts (WC-6 wt.% Co) which were negatively biased at 400 V, resulting in a deposition temperature of similar to 550 degrees C. The film composition, as measured by glow discharge optical emission spectroscopy, was found to vary almost linearly with the gas flow ratio. Cross-sectional transmission electron microscopy in combination with X-ray diffraction (XRD) showed that the films were of single-phase NaCl-structure with a dense columnar microstructure. The intrinsic stress analyzed using the XRD sin(2)psi method, was found to have a maximum of - 5.9 GPa in the composition range of 0.4 less than or equal to x less than or equal to 0.7 which correlated with a maximum in XRD peak broadening due to inhomogeneous strains. The hardness and Young's modulus of the as-deposited TiCxN1-x films were measured by the nanoindentation technique. A maximum in hardness of 45 GPa was found at the same composition range (0.4 Ix I 0.7) as the intrinsic stress maximum. The hardness for x = 0 (TiN) and x = 1 (TiC) were found to be 28 and 36 GPa, respectively. The Young's modulus was constant similar to 610 GPa for films with compositions up to x = 0.6, thereafter it decreased to 540 GPa at x = 1. The increase in intrinsic stress with increasing carbon content is suggested to be due to increased stability of defects created from the collision cascade or/and by a change in the defect structure itself. The fact that hardness showed a maximum at the same composition as residual stress and FWHM indicates that obstruction on dislocation movement has a major influence on the hardness of these films. (C) 2000 Published by Elsevier Science S.A. All rights reserved.
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| 11. |
- Lauridsen, Jonas, et al.
(författare)
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High-rate deposition of amorphous and nanocomposite Ti-Si-C multifunctional coatings
- 2010
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Ingår i: Surface & Coatings Technology. - : Elsevier BV. - 0257-8972 .- 1879-3347. ; 205:2, s. 299-305
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Tidskriftsartikel (refereegranskat)abstract
- Amorphous (a) and nanocomposite Ti-Si-C coatings were deposited at rates up to 16 mu m/h by direct current magnetron sputtering from a Ti3SiC2 compound target, using an industrial pilot-plant system, onto high-speed steel. Si, and SiO2 substrates as well as NI-plated Cu cylinders, kept at a temperature of 200 or 270 degrees C. Electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction analyses showed that TiC/a-C/a-SiC nanocomposites were formed consisting of textured TIC nanocrystallites (nc) embedded in a matrix of a-C and a-SiC. Elastic recoil detection analysis showed that coatings deposited at a target-to-substrate distance of 2 cm and an Ar pressure of 10 mTorr have a composition close to that of the Ti3SiC2 compound target, as explained by ballistic transport of the species Increased target-to-substrate distance from 2 cm to 8 cm resulted in a higher carbon-to-titanium ratio in the coatings than for the Ti3SiC2 compound target, due to different gas-phase scattering properties between the sputtered species The coating microstructure could be modified from nanocrystalline to predominantly amorphous by changing the pressure and target-to-substrate conditions to 4 mTorr and 2 cm, respectively. A decreased pressure from 10 mTorr to 4 or 2 mTorr at a target-to-substrate distance of 2 cm decreased the deposition rate up to a factor of similar to 7 as explained by resputtering and an increase in the plasma sheath thickness. The coatings exhibited electrical resistivity in the range 160-800 mu Omega cm, contact resistance down to 08 m Omega at a contact force of 40 N, and nanoindentation hardness in the range of 6-38 GPa.
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| 12. |
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| 13. |
- Rester, M., et al.
(författare)
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Annealing studies of nanocomposite Ti-Si-C thin films with respect to phase stability and tribological performance
- 2006
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Ingår i: Materials Science & Engineering. - : Elsevier BV. - 0921-5093 .- 1873-4936. ; 429:1-2, s. 90-95
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Tidskriftsartikel (refereegranskat)abstract
- Nanocomposite Ti-Si-C thin films were deposited by dc magnetron sputtering from a Ti3SiC2 target onto Si(1 0 0) and high-speed steel substrates at 300 °C. The as-deposited films consisted of nanocrystalline (nc-) TiCx and amorphous (a-) SiCx, as determined by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Annealing in vacuum up to 1450 °C resulted in improved crystallinity and a decreased volume fraction of the amorphous phase. Additionally, differential scanning calorimetry (DSC) was used to monitor heat flows connected to the respective reactions in the material, where a broad exothermic peak attributed to grain growth of crystalline TiCx appeared, while an exothermic reaction related to the formation of Ti3SiC2 was not detected. Tribological testing in a ball-on-disk setup was conducted at room temperature, 500 and 700 °C against an alumina counterpart. The room temperature measurement resulted in a coefficient of friction value of 0.8, at elevated temperatures the coefficient of friction decreased to 0.4. © 2006 Elsevier B.V. All rights reserved.
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| 14. |
- Öberg, Å., et al.
(författare)
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Conductive nanocomposite ceramics as tribological and electrical contact materials
- 2010
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Ingår i: European Physical Journal. - : EDP Sciences. - 1286-0042 .- 1286-0050. ; 49:2, s. 22902-
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Tidskriftsartikel (refereegranskat)abstract
- Conductive ceramics have widespread use in many industrial applications. One important application for such materials is electrical contact technology. Over the last few years, a new class of nanocomposite ceramic thin film materials has been developed with contact coatings as one key objective. This family of materials has proven to combine the favorable contact properties of metals, such as low electrical and thermal resistivity, and high ductility, with those of ceramics such as low friction and wear rate, high chemical integrity and good high-temperature properties. Furthermore, it is also found that the tribological properties of such materials can be tailored by alloying thus creating a triboactive system. The technology is now industrialized, and a practical example of a contact system utilizing a nanocomposite coating for improved performance is given.
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