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

No abstract

The forcespinning (FS) technique is used here to produce titanium dioxide and carbon composite fibers, as well as zirconium dioxide and carbon composite fibers. Subsequent carbothermal reduction of these fibers facilitated the creation of titanium carbide and zirconium carbide fibers respectably. The role of FS parameters such as the revolutions per minute (RPM) and the collector distance employed is examined. Sol-gel chemistry is used to produce the solutions for the initial FS, and the control of sol-gel chemistry and its effect on the end fiber products is also investigated. The effect of these variables is examined using X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis. The results confirm that titanium and zirconium carbide fibers can be produced using the sol-gel and FS techniques.

No abstract