Effect of Ni Content on Microstructure and Performance of Ni/Ceramic Composite Coating
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JMEPEG https://doi.org/10.1007/s11665-020-04822-w
Effect of Ni Content on Microstructure and Performance of Ni/Ceramic Composite Coating Yaqi Li, Xi Meng, Ren Li, Fanhao Zeng, and Yi Gu (Submitted June 3, 2019; in revised form November 20, 2019) A Ni/ceramic composite coating (Ni-Cermets) was prepared on GH4586 nickel-based alloy by slurry method, and the morphology, phase composition of the coating was analyzed by XRD, SEM and EDS. The effect of the content of Ni on the microstructure and performance of the coating were investigated through the friction experiment, oxidation test and thermal shock experiment, respectively. It was found that this composite coating exhibited excellent oxidation resistance at 900 C. Furthermore, Ni-cermets containing 47 wt.% of nickel (Ni47) showed the best resistance to oxidation, wear and thermal shock. The protection mechanism of this composite coating was different from those of traditional metallic coatings. Keywords
GH4586 alloy, nickel-ceramic coating, oxidation mechanism, performance
1. Introduction Owing to the favorable mechanical properties at elevated temperature, nickel-based superalloys have been extensively applied in aeronautics, astronautics and naval vessels, particularly used as hot component such as disk and blade of turbine engine (Ref 1-3). However, the Ni-based superalloy exhibits poor oxidation resistance and heat ablation properties at service temperature. For liquid oxygen/kerosene (LOX/kerosene) rocket engine, the hot components (turbo pump and combustion gas duct) of Ni-based alloys are subjected to high-temperature (1000 C), high-pressure (about 100 MPa) and high-velocity oxygen-enriched combustion gas. Therefore, protective coatings are widely adopted on hot parts to enhance their resistance to oxidation and hot corrosion. The traditional protective coatings, such as b-NiAl and MCrAlY (M = Ni, Co), derive their protectiveness by forming continuous and intact thermally grown oxide (TGO) on the surfaces. However, the TGO is inclined to peel off because large thermal expansion (CTE) between coating and TGO (Ref 4-6). Thus, it is important to improve the adherence of coating to the Ni-based alloy substrate. In general, oxide ceramic coatings possess excellent properties of oxidation resistance and heat corrosion resistance, and it have been investigated as thermal protection coating on Nibased alloys (Ref 7). Zheng et al. (Ref 8) prepared an enamelAl2O3 coating on NiCoCrAlY-coated K38G superalloy. The coating acted as a barrier to effectively hinder the hightemperature oxidation and hot corrosion of metal substrate. Yaqi Li, Xi Meng, Ren Li, and Yi Gu, School of Materials Science and Engineering, Central South University, Changsha 410083, China; and Fanhao Zeng, National Key Laboratory of Science and Technology for National Defence on High-Strength Structural Materials, Central South University, Changsha 410083, China. Contact e-mails: [email protected] and [email protected].
Journal of Materials Engineering and Performance
Then, enamel-quartz/en
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