TY - BOOK

T1 - Synthesis of ZrX (X=C,O,N) and its possible refractory applications

AU - Kucheryavaya, Anastasia

N1 - embargoed until 08-02-202026

PY - 2021

Y1 - 2021

N2 - The present work focuses on replacement of e.g. zirconia-graphite materials commonly used for refractory applications by even more wear resistant materials including ZrX (X=C,O,N). Combustion of graphite is one main drawback of carbon bonded ceramics, which require a search for a substitution with improved characteristics. Reduction of the material wear might be possible by the application of compounds and solid solutions of the type ZrX (X=C,O,N), thus receiving a material of high oxidation and corrosion resistance. Investigation of Zr-C-O-N system was started decades ago, but never the less the data regarding compositions with advanced corrosion resistance were missing. The present thesis aims to offer possible refractory applications of the compounds within the ZrX (X=C,O,N) system. The results show that synthesized compositions comply with the formula ZrXy (X=C,O,N), where y > 1. Moreover, solid solutions could be divided into two groups depending on the oxygen content which are here called C-type (with lower oxygen content) and O-type. Within the scope of this work the following solid solutions were obtained: ZrC, ZrCO, ZrCN, ZrCON, ZrCO and ZrCON, all of them representing ZrXy (X=C,O,N) with y > 1. For the investigations performed here chemical microanalysis was important, and several methods have been applied. In particulal, transmission electron microscopy together with electron energy loss spectroscopy prooved to yield more reliable results than energy or wave length dispersive X-ray microanalysis for the phases within the ZrX (X=C,O,N) system investigated here. Several properties of the produced specimens were investigated with respect to their suitability for refractory applications in contact with silicate slags. Therefore, specifically solubity in basic and acidic slags as well as oxidation resistance were investigated. ZrXy (X=C,O,N) materials with y > 1 showed to be promising candidates for refractory application. For instance, they could be used either as the reaction-sintered binder material, as main refractory component, or as both. Possible applications include submerged entry nozzels for continuous casting, slide gates, and porous purging ceramics.

AB - The present work focuses on replacement of e.g. zirconia-graphite materials commonly used for refractory applications by even more wear resistant materials including ZrX (X=C,O,N). Combustion of graphite is one main drawback of carbon bonded ceramics, which require a search for a substitution with improved characteristics. Reduction of the material wear might be possible by the application of compounds and solid solutions of the type ZrX (X=C,O,N), thus receiving a material of high oxidation and corrosion resistance. Investigation of Zr-C-O-N system was started decades ago, but never the less the data regarding compositions with advanced corrosion resistance were missing. The present thesis aims to offer possible refractory applications of the compounds within the ZrX (X=C,O,N) system. The results show that synthesized compositions comply with the formula ZrXy (X=C,O,N), where y > 1. Moreover, solid solutions could be divided into two groups depending on the oxygen content which are here called C-type (with lower oxygen content) and O-type. Within the scope of this work the following solid solutions were obtained: ZrC, ZrCO, ZrCN, ZrCON, ZrCO and ZrCON, all of them representing ZrXy (X=C,O,N) with y > 1. For the investigations performed here chemical microanalysis was important, and several methods have been applied. In particulal, transmission electron microscopy together with electron energy loss spectroscopy prooved to yield more reliable results than energy or wave length dispersive X-ray microanalysis for the phases within the ZrX (X=C,O,N) system investigated here. Several properties of the produced specimens were investigated with respect to their suitability for refractory applications in contact with silicate slags. Therefore, specifically solubity in basic and acidic slags as well as oxidation resistance were investigated. ZrXy (X=C,O,N) materials with y > 1 showed to be promising candidates for refractory application. For instance, they could be used either as the reaction-sintered binder material, as main refractory component, or as both. Possible applications include submerged entry nozzels for continuous casting, slide gates, and porous purging ceramics.

KW - Feuerfestwerkstoffe

KW - Zirconiumoxicarbid

KW - Zirconiumoxicarbonitrid

KW - refractories

KW - zirconium oxycarbide

KW - zirconium oxycarbonitride

M3 - Doctoral Thesis

ER -