Niobium carbide synthesis by solid-gas reaction using a rotating cylinder reactor

Abstract

-A rotating cylinder reactor was designed for the synthesis of niobium carbide powders at 1173 K. Niobium carbide, NbC, was prepared by carbothermal reduction starting from commercial niobium pentoxide powders. The reactor was heated using a custom-made, two-part, hinged, electric furnace with programmable temperature control. The design and operational details of the reactor are presented. The longitudinal temperature gradient inside the reactor was determined. Total reaction time was monitored by a gas chromatograph equipped with an FID detector for determination of methane concentrations. The results show that time of reaction depended on rotation speed. NbC was also prepared in a static-bed alumina reactor using the same conditions as in the previous case. The niobium carbide powders were characterized by X-ray diffraction and compared with commercially available products. Morphological, particle size distribution and surface area analyses were obtained using SEM, LDPS and BET, respectively. Therefore, the present study offers a significant technological contribution to the synthesis of NbC powders in a rotating cylinder reactor.

Synthesis and Characterization of Niobium Carbide with Copper Addition Obtained Via Gas Solid Reaction

“…Figure 1 presents the XRD pattern for the 5% and 10% copper added NbC (NbC, 44355-ICSD). The reaction products presented complete conversion to carbides with cubic structure, as indicated by other authors 26,27 . With higher dopant content (Figure 2, top) new peaks arise at θ=43.28° e θ=50.56° which are characteristic of metallic copper (*) (43493-ICSD) which forms a single copper phase.…”

Monophasic Nanostructured Powders of Niobium, Tantalum, and Hafnium Carbonitrides Synthesized by a Mechanically Induced Self‐Propagating Reaction

“…Synthesis of carbides and nitrides of these elements has been carried out by a wide variety of methods that can be classified as (i) thermal treatments, 8–25 (ii) plasma chemical processes, 26 (iii) mechanochemical synthesis, 27,28 and (iv) electrochemical synthesis 29 . However, few reports have been published on the synthesis of carbonitride phases, and only niobium carbonitride has received more attention due to its superconducting properties 26,30,31 .…”

Fabrication of Textured Nb4AlC3 Ceramic by Slip Casting in a Strong Magnetic Field and Spark Plasma Sintering

“…The mean particle size of Nb 4 AlC 3 was measured to be 0.91 μm, and the specific surface area of powder was tested to be 10.2 m 2 /g. In a previous report, NbC particles with the diameter of 27 nm had the specific surface area of only 11.0 m 2 /g 30 . The high specific surface area of the present Nb 4 AlC 3 powder may be ascribed to the existence of numerous delaminations in the fragmented grains.…”

“…In a previous report, NbC particles with the diameter of 27 nm had the specific surface area of only 11.0 m 2 /g. 30 The high specific surface area of the present Nb 4 AlC 3 powder may be ascribed to the existence of numerous delaminations in the fragmented grains. Additionally, it was found that other than the elements of Nb, Al, and C, oxygen was detected in the milled powder by EDS analysis (not shown for brevity).…”