Fabrication and characterization of CrNbSiTiZr high-entropy alloy films by radio-frequency magnetron sputtering via tuning substrate bias
By Yu, Xu; Wang, Junjun; Wang, Linqing; Huang, Weijiu
Published in Surface and Coatings Technology
2021
Abstract
CrNbSiTiZr high-entropy alloy films with different substrate bias voltages (from 0 V to–200 V) were fabricated on 304 stainless steel and Si substrates by radio-frequency magnetron sputtering. The microstructure, mechanical properties, tribological performance, and corrosion resistance were investigated in detail. Results show that all the as-fabricated films exhibit an amorphous phase. The columnar structure becomes featureless with the increase substrate bias due to re-sputtering effects and densification of the film. The film deposited at the bias of –50 V has a high residual compressive stress of –0.82 ± 0.04 GPa and a high hardness of 12.4 ± 0.3 GPa. The wear mechanism of the film is adhesive and slightly abrasive at low negative bias (0, –50, and –100 V), and that at high negative bias (–150 and –200 V) is abrasive. Polarization and electrochemical impedance spectrum measurements reveal that all films have a superior electrochemical corrosion resistance to the 304 stainless steel in 3.5 wt% NaCl solution, which indicates that the film can effectively protect substrate from corrosion. The values of Ecorr, icorr, and Rpo of the film deposited at the bias of –50 V are −283 mV, 0.0178 μA/cm2, and 2.084 × 106 Ω‧cm2, respectively.