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

Abstract

2 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 Ti 3 SiC 2 compound target, due to different gas-phase scattering properties between the sputtered species. The coatings 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-tosubstrate distance of 2 cm decreased the deposition rate up to a factor of ~7 as explained by resputtering and an increase in the plasma sheath thickness. The coatings exhibited electrical resistivity in the range 160-800 µΩcm, contact resistance down to 0.8 mΩ at a contact force of 40 N, and nanoindentation hardness in the range 6-38 GPa.

Microstructure evolution of Ti–Si–C–Ag nanocomposite coatings deposited by DC magnetron sputtering

“…Table 1 also shows the resistivity and mechanical properties of Coatings 1-12. The resistivity values are in the range 77-142 µΩcm, which is a substantial reduction compared to ~250 µΩcm for Ti-Si-C coatings [14], or 1200-5000 µΩcm for nc-TiC/a-C coatings [11,12]. Coatings 10-12 with the highest Ag content has the lowest resistivity (~77 µΩcm), and Coatings 7-9 with relative high carbon content and low Ag content has the highest resistivity (~142 µΩcm).…”

“…Ag would then tend to renucleate on top of the SiC. In this general description, we have neglected the TiC precipitation, but acknowledge that it is a parallel process, which is well described for the Ti-C [11,12] and Ti-Si-C [7,14] systems. Table 1 also shows the resistivity and mechanical properties of Coatings 1-12.…”

“…If a third element like Si is added to TiC, the phase formation complexity increases, but with that also the flexibility to tailor multifunctional materials. In our previous works, we investigated Ti-Si-C based nanocomposites deposited by dc magnetron sputtering and showed that they combine mechanical strength, and low coefficient of friction [13], with high conductivity and low contact resistance [7,10,14]. The addition of a noble metal like Ag to ceramic nanocomposites is in general interesting in a variety of fields such as tribological coatings [15], and antibacterial coatings [16,17].…”

Microstructural and Chemical Analysis of AgI Coatings Used as a Solid Lubricant in Electrical Sliding Contacts

“…To increase the durability of the electrical contacts, new functional materials can be a solution [3][4][5][6]. A liquid lubricant could be an option, but this requires maintenance of the contacts, making it less productive.…”

Ti–B–C nanocomposite coatings deposited by magnetron sputtering

“…127 Figure 2 shows the XPS spectra in three regions from the coatings. Figure 2a shows the 128 Ti2p region, where peaks from both Ti2p 3/2 and Ti2p 1/2 are observed at 455.0 eV, 459.1 129 eV, 461.0 eV, and 464.6 eV, corresponding to Ti-C and Ti-O bonds [24,25]. Note that 130 with increased Ti content the fraction of Ti-O bonds decreases, and the peak at 455.0 eV 131 shifts to lower bonding energies, probably corresponding to Ti-B since B has lower 132 electronegativity than C. Figure 2b shows the C1s region, where two clear peaks areA c c e p t e d M a n u s c r i p t 7 observed at 282.0 and 284.5 eV, attributed to C-Ti and C-C bonds, respectively [14].…”