SYNTHESIS OF COBALT-NICKEL-BORON BASED COMPOSITE POWDERS USING METAL CHLORIDE POWDER BLENDS

1,2 KHOSHSIMA Sina
Co-authors:
1 ALTINTAŞ Zerrin 1,3 SOMER Mehmet 1,3 Balcı Özge
Institutions:
1 Koç University Akkim Boron-Based Materials and High Technology Chemicals Research and Application Center, Rumelifeneri Yolu, 34450 Sarıyer, İstanbul, Turkey, obalci@ku.edu.tr, skhoshsima15@ku.edu.tr
2 Koç University, Graduate School of Sciences and Engineering, Sarıyer, İstanbul, Turkey
3 Koç University, Department of Chemistry, Sarıyer, İstanbul, Turkey
Conference:
27th International Conference on Metallurgy and Materials, Hotel Voronez I, Brno, Czech Republic, EU, May 23rd - 25th 2018
Proceedings:
Proceedings 27th International Conference on Metallurgy and Materials
Pages:
1563-1568
ISBN:
978-80-87294-84-0
ISSN:
2694-9296
Published:
24th October 2018
Proceedings of the conference were published in Web of Science and Scopus.
Metrics:
5 views / 3 downloads
Abstract

This study reports an alternative route for obtaining crystalline metal boride composite powders at low temperatures using various chemical reactions. The ternary system of Co-Ni-B was studied by using anhydrous metal chlorides and sodium borohydride powder mixtures. The reactions were carried out in a sealed reactor under autogenic pressure, placed in a chamber furnace. The unwanted chloride phases were removed by hot water leaching after reaction. Some of the purified powders were annealed at 1100 °C to improve the crystallinity. Effects of different reaction conditions on the formation and microstructure of the final powders were investigated. Phase, chemical and microstructural characterizations and particle size measurements of the synthesized and annealed powders were conducted using X-ray diffractometer (XRD), X-ray fluorescence spectrometer (XRF), scanning electron microscope (SEM/EDX) and dynamic light scattering technique. The results revealed the positive effect of inorganic molten salt mixture (LiCl/KCl eutectic mixture) on the formed phases during the reaction between CoCl2, NiCl2 and NaBH4 powder blends. After their reaction at 750°C in a sealed reactor under autogenic pressure, crystalline cobalt-nickel-boron based composite powders were achieved with an average particle size of 60 nm.

Keywords: Cobalt, nickel, boride, low temperature synthesis, microstructural characterization
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