Badania nad otrzymywaniem azotku krzemu z tlenku krzemu (IV)

Andrzej Pawelec

Abstract

The conditions of the synthesis of silicon nitride in the reaction of silica with ammonia were established in this work. It was found, that magnesium nitride is a catalyst of the reaction. The influence of the following parameters on the course of the process was determined: temperature and sample heating time, ammonia flow rate, substrate layer thickness, silica particle size and catalyst concentration. The mechanism of nitridation of silica by ammonia in the presence of magnesium nitride was elaborated. At the first stage of the process, at temperature about 1350°C, the magnesium-silicon nitride is created in the reaction of silica with magnesium nitride in the ammonia atmosphere. Afterwards, at temperature about 1400°C, the magnesium- silicon nitride decomposes giving silicon nitride and magnesium nitride. Silicon nitride obtained in the previous stage, at temperature above 1400°C, reacts with the rest of silica giving silicon oxynitride as the intermediate product. The nitridation of this compound gives \03B1-Si3N4. At the last stage of the process the recrystallisation and the creation of \03B2-Si3N4 takes place. It was proved, that the obtained Si3N4 powders are suitable to obtain high density silicon nitride ceramics and deposit layers by means of the plasma spraying method.
Diploma typeDoctor of Philosophy
Author Andrzej Pawelec (FC / CICSST)
Andrzej Pawelec,,
- Chair Of Inorganic Chemistry And Solid State Technology
Title in PolishBadania nad otrzymywaniem azotku krzemu z tlenku krzemu (IV)
Languagepl polski
Certifying UnitFaculty of Chemistry (FC)
Disciplinechemical technology / (technology domain) / (technological sciences)
Defense Date18-06-2001
Supervisor Sławomir Podsiadło (FC / CICSST)
Sławomir Podsiadło,,
- Chair Of Inorganic Chemistry And Solid State Technology

Pages165
Keywords in Polishazotek krzemowy, ceramika, związki nieorganiczne, preparatyka nieorganiczna
Abstract in EnglishThe conditions of the synthesis of silicon nitride in the reaction of silica with ammonia were established in this work. It was found, that magnesium nitride is a catalyst of the reaction. The influence of the following parameters on the course of the process was determined: temperature and sample heating time, ammonia flow rate, substrate layer thickness, silica particle size and catalyst concentration. The mechanism of nitridation of silica by ammonia in the presence of magnesium nitride was elaborated. At the first stage of the process, at temperature about 1350°C, the magnesium-silicon nitride is created in the reaction of silica with magnesium nitride in the ammonia atmosphere. Afterwards, at temperature about 1400°C, the magnesium- silicon nitride decomposes giving silicon nitride and magnesium nitride. Silicon nitride obtained in the previous stage, at temperature above 1400°C, reacts with the rest of silica giving silicon oxynitride as the intermediate product. The nitridation of this compound gives \03B1-Si3N4. At the last stage of the process the recrystallisation and the creation of \03B2-Si3N4 takes place. It was proved, that the obtained Si3N4 powders are suitable to obtain high density silicon nitride ceramics and deposit layers by means of the plasma spraying method.
Thesis file
Pawelec_Andrzej_badania.pdf 7.25 MB
Citation count*4 (2015-07-23)

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