Nickel coating on hexagonal boron nitride particles by chemical plating
2007 (English)In: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 38, no 2, 149-157 p.Article in journal (Refereed) Published
In the present work, a new method was developed to produce nickel-coated boron nitride particles, which could be used as a raw material for making abradable seal layer in gas turbine. Hydrazine was employed as the reducing agent, ammonia solution as the complexing agent, nickel sulfate as the main salt, and ammonia-ammonium sulfate as the buffer system. Thermodynamic consideration showed that the hydrazine reduction could take place in the ammonia-ammonium Sulfate system. The applicability of the ammonia-ammonium sulfate system was further confirmed by experiments. Scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) analyses showed that the coated nickel layer was dense without microcracks. The suitable operation conditions were found to be (1) temperature = 343 to 353 K, (2) [Ni](2+) 0.1 to 0.2 mol/L, (3) concentration of ammonia = 90 to 100 mL/L, (4) mass ratio of Ni2+/BN - 1/3, and (5) mole fraction ratio of hydrazine/Ni2+ = 2. The system was found to be more stable in comparison with the sulfate-tartrate system.
Place, publisher, year, edition, pages
2007. Vol. 38, no 2, 149-157 p.
Ammonia; Boron nitride; Hydrazine; Microcracks; Nickel; Plating; Scanning electron microscopy; Complexing agents; Nickel coating; Nickel sulfate; Inorganic coatings
IdentifiersURN: urn:nbn:se:kth:diva-7422DOI: 10.1007/s11663-007-9030-9ISI: 000247008600001ScopusID: 2-s2.0-34250889569OAI: oai:DiVA.org:kth-7422DiVA: diva2:12446
QC 201008042007-08-312007-08-312010-08-04Bibliographically approved