Bing Yang

Ti-containing amorphous carbon nanocomposite coatings prepared by means of eight-target arc-assisted middle frequency magnetron sputtering

Ti-containing amorphous carbon nanocomposite coatings were deposited by using a modified closed field twin unbalanced magnetron sputtering system which is arc assisted and consists of two circles of targets, in an Ar ambient and at a substrate temperature of 100°C High-resolution transmission electron microscopy shows that the coatings contain Ti nanocrystals embedded in the amorphous carbon matrix. Mechanical and tribological properties of the coatings are influenced by the substrate bias voltage and Ti pair-target current. For coatings prepared at a bias of 100 V, the hardness increases from 12 GPa at a Ti-target current of 4 A to 27 GPa at 15 A. The coating at 4 A exhibits very low friction coefficient (~0.07) and excellent tribological performance with a wear rate of about 1.4×10-16 m3 N-1 m-1.

Formation of β-C3N4 Nanocrystals in Ti-Doped Carbon Nitride Films Prepared by Cathode Arc-Assisted Middle-Frequency Magnetron Sputtering

Ti-doped carbon nitride thin films have been deposited by cosputtering Ti and graphite targets in a mixed plasma of Ar and N. Transmission electron microscopy revealed that the nucleation of β-C3N4 could be promoted by Ti incorporation. The N content of the films was found to strongly depend on Ti concentration, even a small amount of Ti incorporation resulted in a drastic increase in N content. An evolution from amorphous layers with fine mixtures of C, N, and Ti to matrices embedded with β-C3N4 nanocrystals was observed with increasing bias voltage.

A cathodic arc enhanced middle-frequency magnetron sputter system for deposition of hard protective coatings

A new cathode arc enhanced magnetron sputter system for deposition of hard protective coatings is reported in this article. This system consists of eight targets: four outer targets are mounted on the wall of the chamber and four inner targets are placed around the center of the chamber. The outer and inner targets form four pair targets and are powered by four middle frequency power supplies. One of the outer targets can run either in the cathode arc mode or in the magnetron sputter mode. The Ti-containing diamond-like carbon nanocomposite coatings were deposited by using this system. The prepared coating exhibits high hardness (∼20 GPa), good adhesion (critical load is 50 N), very low friction coefficient (∼0.07), and excellent tribological performance with a wear rate of 1.4 × 10−16 m3-·N−1·m−1.

High-temperature oxidation behaviour of AlTiSiN and AlCrSiN coatings

ABSTRACT This study was aimed to explore the high-temperature oxidation behaviour of AlTiSiN and AlCrSiN coatings. The coatings were deposited using arc ion plating and annealed in air at a temperature range of 600–1000°C for 2u2005h. The results showed that the oxidation of AlTiSiN coatings started at 900°C and failed at 1000°C. However, the oxidation of AlCrSiN was different from AlTiSiN coatings, which commenced at 800°C and kept stable till 1000°C. The hardness of the as-deposited AlTiSiN coatings dropped from 25.2 to 16.5u2005GPa after 1000°C annealing, while AlCrSiN coatings decreased from 24.2 to 20.5u2005GPa. The AlCrSiN coating exhibits a better high-temperature oxidation resistance than AlTiSiN coating.

Effect of Ion Source Current on the Microstructure and Properties of Cr-DLC Coatings Prepared by Ion Beam Assisted Arc Ion Plating

Cr-containing diamond-like carbon (Cr-DLC) nanocomposite coatings were synthesized by ion beam-assisted arc ion plating with varying hollow cathode ion source (HCIS) currents. The morphologies, com...

Structure and tribological properties of Ti-containing amorphous carbon coatings prepared by cathode arc-enhanced middle-frequency magnetron sputtering

Ti-containing amorphous carbon (Ti-aC) coatings were deposited on cemented carbide and Si substrates by cathode-arc-enhanced closed field middle-frequency unbalanced magnetron sputtering. The coatings were studied by using atomic force microscopy, Raman scattering, nanoindentation, and pin-on-disk testing. The measurements showed that the hardness of the coatings increased from 12 GPa at a Ti content of 1 at.% to 27 GPa at 31 at.%. The coatings exhibited different friction behaviors when facing different mating materials and changed with increasing Ti content. The coating with 4 at.% Ti exhibited excellent tribological performance with a low friction coefficient of 0.07 when facing the cemented carbide.