Effects of Varying Power and Argon Gas Flux on Tribological Properties and High-Speed Drilling Performance of Diamond-Li
- PDF / 5,020,232 Bytes
- 17 Pages / 593.972 x 792 pts Page_size
- 38 Downloads / 209 Views
JMEPEG https://doi.org/10.1007/s11665-020-05242-6
Effects of Varying Power and Argon Gas Flux on Tribological Properties and High-Speed Drilling Performance of Diamond-Like Carbon Coatings Deposited using High-Power Impulse Magnetron Sputtering System Wen Hsien Kao, Yean Liang Su, and Min Yu Shih Submitted: 6 March 2020 / Revised: 25 September 2020 / Accepted: 10 October 2020 This study examines the effects of different pulse powers and gas fluxes on the mechanical and tribological properties and high-speed drilling performance of diamond-like carbon coatings deposited on tungsten carbide substrates by high-power impulse magnetron sputtering. It is shown that an appropriate pulse power is essential in improving the mechanical and tribological properties of the coatings. Specifically, coatings deposited with a pulse power of 5 kW possess a high hardness and good tribological properties, as evidenced by a high hardness-to-elastic modulus ratio. The optimal deposition parameters are determined to be a pulse power of 5 kW and an argon flux of 80 sccm. The resulting coating (designated as C80/5) has the highest hardness (24.95 GPa) of the various coatings and wear rates 11.1, 7.3 and 6.2 times better than those of the bare WC substrate under loads of 6 N, 10 N and 14 N, respectively. Moreover, the coating has low coefficient of friction values of 0.086, 0.098 and 0.062 under loads of 6 N, 10 N and 14 N, respectively. The micro-drilling tests show that the drill coated with C80/5 has a lifetime three times longer than that of an uncoated micro-drill. Keywords
HiPIMS, micro-drill, tribological properties
1. Introduction Diamond-like carbon (DLC) has similar properties to those of diamond in terms of the elastic modulus, hardness, infrared transparency and chemical inertness, and has thus attracted significant attention in the tribological field (Ref 1-3). The DLC coating structure is a metastable form of amorphous carbon with significant sp3 bonding (Ref 4). DLC coatings find many industrial applications nowadays and are not confined to specific treatments and sputtering methods. For example, lowenergy electron-beam treatment has been used to partially modify and functionalize the surface of DLC coatings for biomedical applications (Ref 5). In addition, DLC coatings have been deposited using various sputtering techniques, including direct current magnetron sputtering (DCMS) (Ref 6), plasma-assisted chemical vapor deposition (PACVD) (Ref 7), physical vapor deposition (PVD) (Ref 8), radio frequency (RF) magnetron sputtering (Ref 9), and unbalanced magnetron sputtering (Ref 10). However, conventional DC and RF techniques are limited in terms of the maximum power output that can be applied due to the thermal load imposed on the target by the bombardment of positive ions. Furthermore, the Wen Hsien Kao, Chienkuo Technology University - Institute of Mechatronoptic Systems, Chang Hua, Taiwan; and Yean Liang Su and Min Yu Shih, Department of Mechanical Engineering, National Cheng Kung University, Tainan, Taiwan. Contact e-mail: n18851158
Data Loading...
