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Wetting of ZnO-ceramic with alloys of the silver-copper system in vacuum

   

I. M. Frantsevich Institute for Problems of Materials Science of the NAS of Ukraine, Kyiv
avdu@ukr.net
Usp. materialozn. 2023, 7:77-83
https://doi.org/10.15407/materials2023.07.008

Abstract

Zinc oxide is a wide-gap semiconductor with unique properties, used for the manufacture of catalysts, electrodes, transistors, etc. In these applications, there is a need for metallization and joining of ZnO-based materials, using of molten metal filler is an effective method. Contact of zinc oxide and liquid metals is almost not studied in comparison to other oxide materials. In this work the wetting of zinc oxide based ceramic with metal melts of the silver-copper system in high vacuum was studied. Alloys with concentration of copper (% (at.)) 0 (pure silver), 5, 10, 20, 30, 39, 100 (pure copper) were used. Increasing the concentration of copper in the silver-copper melts significantly improves the wetting of ZnO-ceramic with these liquids, the contact angles decrease from 137° for the pure silver to 28° for the pure copper. Investigations of the microstructure show presence of relatively thin transition layers on the interfaces for silvercopper alloys, for the pure copper case the interface has complex “island-like” microstructure. Also a ruination of ZnO-ceramic substrates due to an interaction with metal melt was noted, the higher copper concentration, the more intensive ruination. Also some signs of the presence of zinc in the metal drops solidified on the zinc oxide surface were revealed, such as, intensive oxidation of the drops in air at room temperature. The oxidation shows complex multiphase microstructure of the solidified drops. After wetting of the zinc oxide with pure copper the solidified metal has microstructure of brass (Cu—Zn alloy) with low zinc concentration. The effects observed can be explained by sublimation of the zinc oxide under experimental conditions (high temperatures, vacuum) with formation of gaseous products (oxygen and vapor of zinc), which subsequently dissolve in silver-copper liquid drops. In particular, the dissolution of oxygen in the Ag—Cu melt improves its wetting of surfaces of solid oxides and presence of zinc in solidified drops provides its oxidization in air.


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WETTING WITH METALS, CONTACT INTERACTION, MICROSTRUCTURE, TRANSITION LAYER, ZINC OXIDE

References

1. Morkoc, H., Ozgur, U. (2008). Zinc oxide: fundamentals, materials and device technology. John Wiley & Sons, 488 р.

2. Ozgur, U., Alivov, Y. I., Liu, C., Teke, A., Reshchikov, M. A., Dogan, S., Avrutin, V., Cho, S.-J., Morkoc, H. A. (2005). Сomprehensive review of ZnO materials and devices. J. Appl. Phys., Vol. 98, is. 4 (041301), pp. 1—103. doi: https://dx.doi.org/10.1063/1.1992666

3. Nikolayeva, N. S. (2012). Ag melt wetting of ZnO based ceramics. IX Rossiyskaya yezhegodnaya konf. molodykh nauchnykh sotrudnikov i aspirantov “Fiziko-khimiya i tekhnologiya neorganicheskikh materialov”, Sbornik materialov, Moskva: IMET RAN, 395 p. [in Russian].

4. Jiangyan, Wang, Hansen, Wang, Jin, Xie, Ankun, Yang, Allen, Pei, Chun-Lan, Wu, Feifei, Shi, Yayuan, Liu, Dingchang, Lin, Yongji, Gong, Yi, Cui (2018). Fundamental study on the wetting property of liquid lithium. Energy Storage Mater., No. 14, pp. 345—350. doi: https://doi.org/10.1016/j.ensm.2018.05.021

5. Van Herwijnen, T., De Jong, W. A. (1974). Brass formation in a copper/zinc oxide CO shift catalyst. J. Catalysis, Vol. 34, No. 2, pp. 209—214.  doi: https://doi.org/10.1016/0021- 9517(74)90030-X

6. Herman, R. G., Klier, K., Simmons, G. W., Finn, B. P., Bulko, J. B., Kobylinski, T. P. (1979). Catalytic synthesis of methanol from COH2 : I. Phase composition, electronic properties, and activities of the Cu/ZnO/M2O3 catalysts. J. Catalysis, Vol. 56, No. 3, pp. 407—429. doi: https://doi.org/10.1016/0021-9517(79)90132-5

7. Klier, K. (1984). Structure and function of real catalysts. Appl. Surface Sci., Vol. 19, No. 1—4, pp. 267—297. doi:  https://doi.org/10.1016/0378-5963(84)90066-7

8. Spencer, M. S. (1987). α-Brass formation in copper/zinc oxide catalysts: I. Bulk equilibrium concentrations of zinc under methanol synthesis and water-gas shift reaction conditions. Surface Sci., Vol. 192, No. 2—3, pp. 323—328. doi: https://doi.org/10.1016/S0039- 6028(87)81127-5

9. Topsoe, N.-Y., Topsoe H. (1999). FTIR studies of dynamic surface structural changes in Cubased methanol synthesis catalysts. J. Molecular Catalysis A: Chemical, Vol. 141, No. 1—3, pp. 95—105. doi: https://doi.org/10.1016/S1381-1169(98)00253-2

10. Poels, E., Brands, D. (2000). Modification of Cu/ZnO/SiO2 catalysts by high temperature reduction. Appl. Catalysis A: General, Vol. 191, No. 1—2, pp. 83—96. doi: https://dx.doi.org/10.1016/S0926-860X(99)00307-5

11. Fujitani, T., Nakamura, J. (2000). The chemical modification seen in the Cu/ZnO methanol synthesis catalysts. Appl. Catalysis A: General, Vol. 191, No. 1—2, pp. 111—129. doi: https://doi.org/10.1016/S0926-860X(99)00313-0

12. Batyrev, E. D., Van Den Heuvel, J. C., Beckers, J., Jansen, W. P. A., Castricum, H. L. (2005). The effect of the reduction temperature on the structure of Cu/ZnO/SiO2 catalysts for methanol synthesis. J. Catalysis, Vol. 229, No. 1, pp. 136—143. doi: https://doi.org/10.1016/j.jcat.2004.10.012

13. Van den Berg, M. W. E., Polarz, S., Tkachenko, O. P., Klementiev, K. V., Bandyopadhyay, M., Khodeir, L., Gies, H., Muhler, M., Grünert, W. (2006). Cu/ZnO aggregates in siliceous mesoporous matrices: Development of a new model methanol synthesis catalyst. J. Catalysis, Vol. 241, No. 2, pp. 446—455. doi: https://doi.org/10.1016/j.jcat.2006.05.020

14. Sanches, S. G., Flores, J. H., de Avillez, R. R., Pais da Silva, M. I. (2012). Influence of preparation methods and Zr and Y promoters on Cu/ZnO catalysts used for methanol steam reforming. Int. J. Hydrog. Energy, Vol. 37, No. 8, pp. 6572—6579. doi: https://doi.org/10.1039/C5RA24163D

15. Wang, R., Wang, H., Weng, X., Dai, J., Gong, Z., Zhao, C., Lu, J., Cui, Y., Bao, X. (2021). Exploring the phase transformation in ZnO/Cu(111) model catalysts in CO2 hydrogenation. J. Energy Chem., No. 60, pp. 150—155. doi: https://dx.doi.org/10.1016/j.jechem.2020.12.023

16. Pantazopoulos, G., Pantazopoulos, G. (2008). Characterization of the Microstructural aspects of machinable a-b phase brass. mater. Sci. https://www.semanticscholar.org/paper/Characterization-of-the-Microstructural-Aspects-of Pantazopoulos-Pantazopoulos/b755dc2d4c62fd7475703eba4926f13484e63fb6

17. F*A*C*T-EQUILIB. URL: https://www.crct.polymtl.ca/equiweb.php

18. Anthrop, D. F., Searsy, A. W. (1964). Sublimation and thermodynamic properties of zinc oxide. J. Phys. Chem., Vol. 68, No. 8, pp. 2335—2342. doi: https://doi.org/10.1021/j100790a052

19. Wurster, D. E., Oh, E., Wang, J. C. (1995). Determination of the mechanism for the decrease in zinc oxide surface area upon high-temperature drying. J. Pharm. Sci., Vol. 84, No. 11, pp. 1301—1307. doi: https://doi.org/10.1002/jps.2600841109

20. Naydich, Yu. V. (1972). Contact phenomena in metallic melts. Kyev: Nauk. dumka, 196 p. [in Russian].