Ultra-fine zirconium diboride powders prepared by a combined sol–gel and spark plasma sintering technique

Abstract

Ultrafine ZrB 2 powders were successfully synthesized by using a novel method that combines the sol-gel process with the rapid synthesis of spark plasma sintering (SPS). The sol-gel method utilized a soluble zirconium-containing organic precursor consisting of zirconium n-propoxide, boric acid and furfuryl alcohol as the source materials for zirconium, boron and carbon respectably. From this precursor pure ZrB 2 was successfully synthesized at 1700°C for 5 min using the optimal molar ratios of n(B)/n(Zr) = 4 and n(C)/n(Zr) = 20. During the carbo/borothermal reductions the formation of ZrB 2 occurred from the precursor prior to the ZrC and B 4 C formation. Therefore neither ZrC nor B 4 C XRD peaks were detected in the final product. It was also found that the fast heating rates employed during SPS were able to retard the grain growth of the ZrB 2 particles. Graphical AbstractKeywords Zirconium diboride Á Sol-gel Á Spark plasma sintering

The effect of sputtering atmosphere parameters on dielectric properties of the ferromagnetic alloy – ferroelectric ceramics nanocomposite (FeCoZr)x(PbZrTiO3)(100−x)

“…Among the "bottom up" techniques such ones as: ion [31,32] and magnetron sputtering [33,34], ion implantation [35,36], plasma techniques [37,38] and chemical methods [39] should be distinguished for their advantageous application to the development of nano-sized materials. These methods consist in transiting the material from its solid state (referred to as a target) into the gaseous phase followed by its deposition onto the substrate.…”

Carbothermal conversion of self‐supporting organic/inorganic interpenetrating networks to porous metal boride monoliths

“…Our strategy is different from previous works by using FA, zirconium n ‐propoxide, and BA to prepare ZrB 2 ‐based ceramics . Powders are commonly obtained in previous sol‐gel routes.…”

“…[57][58][59] Our strategy is different from previous works by using FA, zirconium n-propoxide, and BA to prepare ZrB 2 -based ceramics. 23,26,27 Powders are commonly obtained in previous sol-gel routes. In our cases, the FA polymerization rate is tuned by the solvent shielding effect from hydrolysis-generated or added n-butanol.…”

“…Unlike silicon carbide, which can be directly formed by pyrolyzing Si‐C bonded polymeric precursors (eg, polycarbosilane), MB materials from liquid‐based processes are routinely obtained by carbothermal reductions at high temperatures (>1300°C) among carbon, metal, and boron oxides . It is more common to obtain powdery MB materials via liquid‐based processes under ambient pressure drying, and sometimes even under supercritical drying conditions . For synthesizing porous MB monoliths via sol‐gel approach, the monoliths have to survive at least two critical processes: drying and pyrolysis at high temperatures.…”

“…[22][23][24][25] It is more common to obtain powdery MB materials via liquid-based processes under ambient pressure drying, and sometimes even under supercritical drying conditions. 23,[25][26][27][28][29] For synthesizing porous MB monoliths via sol-gel approach, the monoliths have to survive at least two critical processes: drying and pyrolysis at high temperatures.…”