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A duplex composite coating consisting of electrodeposited SiO 2 interlayer and glass-ceramic coating was fabricated on TiAl alloy. The oxidation behavior of the composite coating was studied in air at 1000 °C. The composition, morphology, and microstructure of the oxide scale were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive spectroscopy (EDS). Results showed that the composite coating exhibited outstanding resistance against high temperature oxidation. After 100 h oxidation, no scale spallation was observed and the weight gain was only 1.16 mg cm−2. The inward diffusion of oxygen and outward diffusion of Ti were efficiently prevented. A continuous and adherent Al 2 O 3 layer was formed at the coating/substrate interface. The electrodeposited SiO 2 interlayer could improve the adhesion between the substrate and glass-ceramic coating. • Glass-ceramic coating and SiO 2 interlayer were fabricated on TiAl alloy. • SiO 2 interlayer can dissolve into the glass-ceramic coating and reduce its mobility. • The adhesion property of the glass-ceramic coating was enhanced. • The formation of nitride at the coating/substrate interface was suppressed. [ABSTRACT FROM AUTHOR]

• A glass-ceramic coating incorporated with YSZ and ZrB 2 was prepared. • An electrodeposited SiO 2 interlayer was introduced into the coating system. • The coating bulk and interfacial structures were both reinforced by the particles. • The coated TiAl alloy exhibited satisfactory oxidation resistance at 1000 ℃. With electrodeposited SiO 2 film as the interlayer, 8YSZ (8.0 wt.% Y 2 O 3 partially stabilized ZrO 2) and ZrB 2 particles co-incorporated glass-ceramic coating was fabricated on TiAl alloy. The oxidation performance and interfacial reaction behavior of this coating were studied. The compact glass-ceramic coating inhibited the inward diffusion of oxygen. The reaction between the SiO 2 interlayer and the potassium silicate coating benefited to improve the coating adhesion property and suppress the coating degradation at the coating/substrate interface. Due to the synergy of the incorporated particles and SiO 2 interlayer, both the oxidation performance and interfacial structure of the glass-ceramic coating were improved. [ABSTRACT FROM AUTHOR]

PDA-GO-CeO 2 is employed as the multifunctional filler to prepare PDA-GO-CeO 2 -EP composite coating. PDA-GO-CeO 2 shows excellent dispersion and compatibility in epoxy resin, which further improves the compactness of the coating. Meanwhile, thanks to the physicochemical characteristics of PDA-GO-CeO 2 and its interaction with epoxy resin, PDA-GO-CeO 2 -EP composite coating exhibits high adhesion force, physical barrier, and reliable active protection, anti-UV aging abilities. [Display omitted] • Low defect functionalized PDA-GO-CeO 2 are prepared via a facile stepwise method. • PDA-GO-CeO 2 strengthens the interface structure coating/metal system. • PDA-GO-CeO 2 -EP coating exhibits excellent anti-corrosion and anti-UV abilities. In the marine environment, besides external damage and internal defects, ultraviolet (UV) radiation is also a pivotal factor affecting the stable properties of coatings. Improving the anti-UV aging and active protection properties is beneficial to prolong the service life of coatings. Herein, the PDA-GO-CeO 2 composite material is obtained through a facile stepwise growth of polydopamine (PDA) and CeO 2 on GO nanosheets and further preparing a multifunctional anti-corrosion PDA-GO-CeO 2 -EP coating. As expected, composite coating displays strong adhesion force (6.9 MPa) and tensile strength (21.1 MPa), profiting from the enhanced crosslinking density and interface structure caused by PDA-GO-CeO 2 and resin matrix interaction. Since low defect functionalized PDA-GO-CeO 2 constructs the reinforced physical barrier, the anti-corrosion ability of PDA-GO-CeO 2 -EP coating (109.7 Ω·cm2) is more dependable than those of EP (106.7 Ω·cm2), GO-EP coating (108.8 Ω·cm2) and PDA-GO-EP (109.1 Ω·cm2) coatings after immersing in 3.5 wt.% NaCl solution for 100 d. Thanks to the synergistic effect of PDA/CeO 2 , the active protection performance of PDA-GO-CeO 2 -EP coating is endowed, which is further proved through the in situ scanning vibrating electrode technique (SVET). Following the UV aging treatment, PDA-GO-CeO 2 -EP coating shows minor gloss loss (20.4 %) and better adhesion force (4.3 MPa). Furthermore, the resistance value of PDA-GO-CeO 2 -EP coating is 7.03 × 106 Ω cm2 after 30 d immersion in saline solution, which is 242 times greater than that of EP coating (2.90 × 104 Ω cm2). This dependable performance of PDA-GO-CeO 2 -EP coating comes from the reflection, refraction, and absorption of UV rays by nanoscale CeO 2 particles. Consequently, this work offers a simple and promising strategy for fabricating multifunctional long-term protection coatings, thus hopefully extending the service life of marine engineering equipment. [ABSTRACT FROM AUTHOR]

Ni nanoparticle incorporated SiO 2 coating was fabricated on Ti48Al2Nb2Cr alloy by electro-codeposition. Results showed that the Ni-SiO 2 composite coating exhibits good isothermal and cyclic oxidation resistance at 900 ºC. The incorporation of Ni particles can adjust the coating thermal stress. After oxidation, no crack or pore can be found in the Ni-SiO 2 composite coating. The consumption of the inward diffused oxygen could reduce the oxygen partial pressure at the coating/substrate interface, therefore promoting the selective oxidation of Ti48Al2Nb2Cr to form Al 2 O 3. Owing to the good compatibility with SiO 2 , the oxidation product of NiO could strengthen the structure of the coating. [Display omitted] • The Ni-SiO 2 composite coating exhibits good isothermal and cyclic oxidation resistance. • The incorporated Ni particles can adjust the coating thermal stress and prevent the generation of cracks. • The inward diffused oxygen is consumed by the Ni particles, promoting the selected oxidation of Ti48Al2Nb2Cr to form α-Al 2 O 3. • The structure of the oxide scale can be improved by the oxide product of NiO. [ABSTRACT FROM AUTHOR]

A novel Al–Si composite coating was fabricated on γ-TiAl by the combination of magnetron sputtered Al coating and subsequently electrodeposited SiO 2 coating. The oxidation performance of the specimens was evaluated in static air at 900 °C. Results shown that the Al–Si composite coating can act as an efficient oxygen migration barrier and provide good oxidation resistance. During the oxidation process, an Al 2 O 3 enriched layer formed beneath the composite coating. The interfacial reaction between the composite coating and alloy resulted in the generation of Al 2 O 3 and Ti 5 Si 3. Image 1 • A novel Al–Si composite coating was fabricated on γ-TiAl by a two-step method. • This Al–Si composite coating can prevent the formation of Al-depletion layer. • The interfacial reaction between the composite coating and alloy resulted in the generation of Al 2 O 3 and Ti 5 Si 3. • This Al–Si composite coating can reduce the coating/alloy interface hardness and improve the oxidation resistance. [ABSTRACT FROM AUTHOR]