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The CrAlC coating has broad application prospects as a high temperature protective material due to its unique properties. However, it is difficult to control the properties of CrAlC coating due to the multiphase structure produced by thermally induced solid-reaction. In this paper, the CrAlC coating was prepared by filtered cathodic vacuum arc (FCVA) technology. In order to elucidate the relationship between the phase structure evolution and the properties, the structure, mechanical and electrochemical properties of the CrAlC coating before and after annealing were systematically investigated. The results illustrated that the CrAlC coating changed from amorphous structure to crystalline structure after annealing, and the phase composition varied with the increases of annealing temperature. As the annealing temperature increased from 700 °C to 800 °C, the content of Cr 23 C 6 and Al 4 C 3 increased. However, with further increasing the annealing temperature to 900 °C, the content of Al 4 C 3 gradually decreased, and the Cr 23 C 6 phase was transformed into Cr 7 C 3 and Cr 3 C 2 phases. In addition, the hardness and corrosion resistance of the coating first increased and then decreased with the increase of annealing temperature. When the annealing temperature was 800 °C, the CrAlC coating had the highest hardness (18.28 GPa) and the best corrosion resistance with the smallest corrosion current density (8.54 × 10-9 A/cm2). [Display omitted] • CrAlC coatings annealed at different temperatures were prepared. • A multi-phase structure dominated by Cr 23 C 6 with little Al 4 C 3 and Cr 3 C 2 was formed. • Increasing annealing temperature causes hardness to increase first and then decrease. • Cr 23 C 6 significantly improved the electrochemical corrosion resistance of the CrAlC coating. [ABSTRACT FROM AUTHOR]

The CrAlC coating has broad application prospects as a high temperature protective material due to its unique properties. However, it is difficult to control the properties of CrAlC coating due to the multiphase structure produced by thermally induced solid-reaction. In this paper, the CrAlC coating was prepared by filtered cathodic vacuum arc (FCVA) technology. In order to elucidate the relationship between the phase structure evolution and the properties, the structure, mechanical and electrochemical properties of the CrAlC coating before and after annealing were systematically investigated. The results illustrated that the CrAlC coating changed from amorphous structure to crystalline structure after annealing, and the phase composition varied with the increases of annealing temperature. As the annealing temperature increased from 700 °C to 800 °C, the content of Cr 23 C 6 and Al 4 C 3 increased. However, with further increasing the annealing temperature to 900 °C, the content of Al 4 C 3 gradually decreased, and the Cr 23 C 6 phase was transformed into Cr 7 C 3 and Cr 3 C 2 phases. In addition, the hardness and corrosion resistance of the coating first increased and then decreased with the increase of annealing temperature. When the annealing temperature was 800 °C, the CrAlC coating had the highest hardness (18.28 GPa) and the best corrosion resistance with the smallest corrosion current density (8.54 × 10-9 A/cm2). [Display omitted] • CrAlC coatings annealed at different temperatures were prepared. • A multi-phase structure dominated by Cr 23 C 6 with little Al 4 C 3 and Cr 3 C 2 was formed. • Increasing annealing temperature causes hardness to increase first and then decrease. • Cr 23 C 6 significantly improved the electrochemical corrosion resistance of the CrAlC coating. [ABSTRACT FROM AUTHOR]

• Ti 3 AlC 2 coatings were quickly prepared by FCVA and annealed at 800 °C for 1 h. • Ti 3 AlC 2 phase was formed in the coating at high C 2 H 2 flow rates (≥ 12 sccm). • Hardness and elastic modulus of coatings increased as the C 2 H 2 flow rate increased. • Ti 3 AlC 2 coatings showed high hardness and excellent corrosion resistance. Ti 3 AlC 2 MAX phases have attracted increasing attention due to their unique properties. However, high synthesis temperatures of Ti 3 AlC 2 bulk materials limit their further development. In this work, Ti 3 AlC 2 coatings were prepared by a two-step method with filtered cathode vacuum arc (FCVA) deposition at room temperature and annealing at 800 °C for 1 h. The structure and properties of coatings were investigated. The results showed that the formation of Ti 3 AlC 2 phase in the annealed coating depended on the C 2 H 2 flow rate during deposition. At low C 2 H 2 flow rates (≤ 9 sccm), almost no Ti 3 AlC 2 phase was formed. As the C 2 H 2 flow rate increased, the annealed coatings mainly exhibited Ti 3 AlC 2 phases, the texture of which transformed from (104) to (105) planes. Meantime, the hardness of Ti 3 AlC 2 coatings continuously increased to a maximum of 20.7 GPa, and the corrosion resistance first increased and then decreased with the increase of C 2 H 2 flow rate. [ABSTRACT FROM AUTHOR]

In order to improve the surface properties of Al alloy, TiAlN ceramic coatings composed of alternating TiAl layer and TiAlN layer were prepared by FCVA technology. The influence of N 2 flow rate on the microstructure, mechanical and tribological performance of multilayer TiAlN coatings was systematically studied. The results showed that the coating exhibited a multi-phase structure with mainly fcc TiAlN phase and a small amount of TiN and AlN phases. As the N 2 flow rate increased from 50 to 80 sccm, the preferred orientation varied from TiAlN (220) plane to (111) plane due to lattice distortion. The hardness and elastic modulus of multilayer TiAlN coatings first increased and then decreased with the increase of N 2 flow rate. However, the average friction coefficient and wear rate of multilayer TiAlN coatings exhibited an opposite trend to the hardness, H/E and H3/E2 values. The adhesion gradually decreased from 27.3 to 14.9 N due to the continuous increase of the compressive stress in the coating with the increase of N 2 flow rate. When the N 2 flow rate was 70 sccm, the coating showed the lowest average friction coefficient and wear rate, which was attributed to the highest hardness and the best resistance to cracking and plastic deformation. [ABSTRACT FROM AUTHOR]

TiSiN coatings have attracted extensive attention due to excellent performance in cutting tools, Marine engineering equipment and ship critical components. However, due to the many microparticles and micropores on the coating surface prepared by traditional PVD techniques, the performance of the coatings, especially corrosion resistance, is seriously affected. Therefore, the preparation of high quality TiSiN coatings is very important for the industrial applications. In this study, high-quality TiSiN coatings were prepared by FCVA technique. The effect of N 2 flow rate on microstructure, mechanical properties and corrosion resistance of TiSiN coating was investigated. The results showed that all TiSiN coatings presented smooth and compact microstructure without cracks. Meanwhile, TiSiN coatings had a nanocomposite structure of amorphous Si 3 N 4 encapsulated TiN crystallites and possessed a preferred orientation of TiN (200) plane. With the increase of N 2 flow rate, the grain size and hardness increased first and then decreased. When N 2 flow rate is 20 sccm, the hardness of TiSiN coating reached the maximum owing to the fine grain strengthening effect. Moreover, TiSiN coating deposited N 2 flow rate of 40 sccm had the best corrosion resistance, with the highest charge transfer resistance and pore resistance, which was primarily related to the best surface quality. • High quality TiSiN coating with smooth and compact microstructure were prepared by FCVA technique. • The effect of N 2 flow rate on the structure and properties of TiSiN coating were studied. • The excellent corrosion resistance was due to the good surface quality of TiSiN coating prepared by FCVA technique. [ABSTRACT FROM AUTHOR]