High-rate deposition of amorphous and nanocomposite Ti-Si-C multifunctional coatings

• 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.

Ämnesord

NATURVETENSKAP  -- Kemi -- Oorganisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Inorganic Chemistry (hsv//eng)

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Nyckelord

Nanocomposites

TiSiC coatings

Pilot plant

Magnetron sputtering

Resistivity

Electron microscopy

Inorganic chemistry

Oorganisk kemi

Kemi med inriktning mot oorganisk kemi

Chemistry with specialization in Inorganic Chemistry

Physics

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