Investigation on the formation of tungsten carbide in tungsten-containing diamond like carbon coatings

Abstract

A series of tungsten-containing diamond-like carbon (Me-DLC) coatings have been produced by unbalanced magnetron sputtering using a Hauzer HTC-1000 production PVD system. Sputtering from WC targets has been used to form W-C:H coatings. The metal to carbon ratio has been varied to study changes in the metal carbide formation and distribution within the amorphous hydrocarbons (a-C:H) matrix. The difference in the formation of the metal carbide is then linked to changes in the mechanical and tribological properties of the coatings. Detailed high-resolution cross-section TEM has been carried out to analyze the microstructure of the coatings. By changing the amount of a-C:H in the W-C:H coatings, the coefficient of friction could be varied between 0.129 and 0.312. The hardness was found to vary between 8 and 27.5 GPa by using different acetylene gas flows. It was observed that all coatings did have a pronounced multilayered structure. ᮊ

Electrochemical and antimicrobial properties of diamondlike carbon-metal composite films

“…These values are similar to those observed in layered WC/DLC and TiC/DLC composites prepared using magnetron sputtering or electron cyclotron resonance chemical vapor deposition techniques (nanohardness~27 GPa). In addition, these values are significantly greater than those observed in a-C:H-copper coatings prepared using plasma-enhanced chemical vapor deposition (PECVD) or hybrid microwave plasma-assisted chemical vapor deposition/sputtering techniques (nanohardness~10 GPa) [63][64][65][66][67].…”

Nanostructured TiC/a-C coatings for low friction and wear resistant applications

“…Hydrogenated nc-TiC/a-C:H coatings were deposited with closed-field unbalanced magnetron sputtering in an argon/ acetylene atmosphere in a Hauzer HTC-1000 coating system, which was configured of two Cr targets and two Ti targets opposite to each other. The detailed set-up of the coating system has been documented elsewhere [3]. The Cr targets were used to create an intermediate layer between the nc-TiC/a-C:H coating and the substrate material.…”

Microstructure and mechanical properties of Ti/AlTiN/Ti-diamondlike carbon composite coatings on steel

“…[13][14][15] The wear rate correlates with both hardness and with the intrinsic nanometer-scale roughness of the Me-DLC. 13 Such research on friction and sliding characteristics of Me-DLC has already been carried out, [16][17][18][19][20] and the possibility of nonlubricated sliding has been demonstrated. However, thin film hardness generally decreases with a larger fraction of metal inclusions, and film damage due to abrasion will be more likely than delamination.…”