Synthesis of ultrafine ZrB2 powders by sol-gel process

Abstract

Ultrafine zirconium diboride (ZrB 2 ) powders have been synthesized by sol-gel process using zirconium oxychloride (ZrOCl 2 $8H 2 O), boric acid (H 3 BO 3 ) and phenolic resin as sources of zirconia, boron oxide and carbon, respectively. The effects of the reaction temperature, B/Zr ratio, holding time, and EtOH/H 2 O ratio on properties of the synthesized ZrB 2 powders were investigated. It was revealed that ultrafine (average crystallite size between 100 and 400 nm) ZrB 2 powders can be synthesized with the optimum processing parameters as follows: (i) the ratio of B/Zr is 4; (ii) the solvent is pure ethanol; (iii) the condition of carbothermal reduction heat treatment is at 1550°C for 20 min.

Carbothermal reduction synthesis of ZrB2 nanofibers via pre-oxidized electrospun zirconium n-propoxide

“…7, that the surface of the ZrB 2 nanofibers became smooth with decreasing of the rate of preoxidization step to 2 1C/min. The main reason for this phenomenon was that the higher temperature promoted ZrB 2 grains to nucleate much more rapidly than growing of the grains [30]. Notably, the pyrolyzed products maintained their initial long fibrous shape quite well with high purity.…”

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

“…high temperature performance in aerospace applications) make the family of ultra-high temperature ceramics worthy of research. Zirconium diboride (ZrB 2 ) possesses various unique physical and chemical properties, including low density, high melting-point and resistance to high-temperature oxidation [1][2][3][4][5][6]. These properties make ZrB 2 an attractive candidate for applications in the aerospace industry [7].…”

Facile Carbothermal Reduction Synthesis of ZrB2Nanoparticles: The Effect of Starting Precursors

“…Various techniques have been developed to synthesize ZrB 2 nanoparticles, including solid-state reaction synthesis [1], sol-gel reaction synthesis [2], mechanochemical synthesis [3], and self-propagating high temperature synthesis [4]. The sol-gel process is one of the leading techniques for the production of high-purity ultrafine ceramic powders with different morphologies [5].…”

“…The sol-gel process is one of the leading techniques for the production of high-purity ultrafine ceramic powders with different morphologies [5]. Generally, the effects of zirconium complexes on the preparation of ZrB 2 nanoparticles have been less reported in the literature [2,6]. The employing ligands used in the sol-gel process are Lewis bases that have lone pairs on nitrogen and oxygen for binding with transition metals.…”