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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]

[Display omitted] • The precursor containing NiSO 4 and TEOS was applied to prepare Ni-SiO 2 coating. • The stress in the sintered Ni-SiO 2 coatings is reduced due to the incorporated Ni. • The Ni particles can withstand stress change and strengthen the coating structure. • The oxidation product of nickel, NiO, can impede the occurrence of cracking. In this study, a novel SiO 2 coating with the incorporation of nickel was prepared on Ti48Al2Nb2Cr alloy by co-electrodeposition. The effect of Ni in SiO 2 coating on the oxidation resistance of Ti48Al2Nb2Cr alloy at 900 °C was investigated. Due to the incorporation of nickel, the high temperature performance of the SiO 2 coating is promoted. For the Ni-modified SiO 2 coating, diffusion of oxygen to the substrate is effectively inhibited by a compact oxide scale composed of SiO 2 outer layer, Al 2 O 3 middle layer, and Ti 5 Si 3 inner layer. The incorporated Ni reinforces the structure and withstands the stress change of the SiO 2 coating. Moreover, the occurrence of cracking is impeded by NiO which is formed during oxidation. [ABSTRACT FROM AUTHOR]

SiOC coating was electrodeposited on TiAl alloy to improve the high temperature oxidation resistance. The mass gain of the compact SiOC coating is 0.06 ± 0.026 mg cm-2, which is one order of magnitude lower than that of TiAl alloy. The SiOC coating exhibits good thermal stability and partial amorphous SiOC transforms into crystal SiO 2 or SiC. After oxidation, no obvious pore can be found in the coating. Moreover, an Al 2 O 3 layer is generated due to the enrichment of Al and the low oxygen partial pressure at the coating/substrate interface, therefore improving the barrier property of the oxide scale. [Display omitted] • SiOC coating is prepared on TiAl alloy by electrodeposition. • The high temperature oxidation resistance of the TiAl alloy with the SiOC coating is dramatically improved. • Thermal exposure results in partial amorphous SiOC transforms into crystal SiO 2 or SiC. • The outward diffused Al can strengthen the network structure of the SiOC coating and establish an Al 2 O 3 intermediate layer. [ABSTRACT FROM AUTHOR]

[Display omitted] • A multifunctional coating was prepared via composite GO material (GO-CN/CON-U) and EP. • GO-CN/CON-U enhanced the mechanical and hydrophobic performance of epoxy coating. • The GO-CN/CON-U-EP coating exhibited excellent passive/active anti-corrosion ability. Effectively reducing microdefects and endowing coatings with active protection are critical factors in prolonging the service life of coatings. Herein, a novel ceria nanoparticle decorated cerium organic network (GO-CN/CON-U) is in-situ prepared on graphene oxide (GO) via a simple one-step method. Then, a multifunctional coating is obtained by introducing GO-CN/CON-U into the epoxy resin matrix. The coating surprisingly exhibits exceptional mechanical properties and hydrophobicity attributing to the optimized crosslinking degree, compactness, and toughness due to the interaction between composite materials and epoxy resin, while its sustained anti-corrosion performance (around 109 Ω·cm2) also displays three orders of magnitude higher than that of pure epoxy coating (less than 106 Ω·cm2) even after 60 d of immersion in the aggressive media. An active protective mechanism was further proposed according to the UV–Vis and microelectrochemical test results, revealing that a shielding film can be promptly formed on the surface of Q235 steel when damage occurs against the attack of aggressive ions due to the release of Ce3+/Ce4+ and organic inhibitors from GO-CN/CON-U under acidic responsiveness. In brief, the present work provides a simple but attractive strategy for the preparation of long-lasting multifunctional protective coatings. [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]

• Electrodeposited SiO 2 coating can efficiently improve the hot corrosion resistance of TiAl alloy. • Compact and adherent corrosion scale generates during the hot corrosion process. • The dissolution of SiO 2 into the molten sodium salt leads to the generation of Na 2 Si 4 O 9. • The compact Al 2 O 3 layer at the coating/alloy interface benefits to improve the hot corrosion resistance. To improve the hot corrosion resistance, thickness controllable SiO 2 coating was electrodeposited on TiAl alloy. The hot corrosion behavior of the specimens contaminated with 75 wt.% Na 2 SO 4 + 25 wt.% NaCl salt mixture was investigated at 700 °C. Results showed that the generation of compact amorphous SiO 2 embedded with Na 2 Si 4 O 9 and cristobalite was responsible for the enhanced hot corrosion resistance. Moreover, the SiO 2 coating does not only act as a diffusion barrier to sulfur and chlorine but also decreases the oxygen partial pressure at the coating/alloy interface, therefore promoting the selective oxidation of Al to form protective Al 2 O 3 layer. [ABSTRACT FROM AUTHOR]