Herstellung und Untersuchung von MgAlON gebundenen Feuerfestprodukten

Translated title of the contribution: Production and investigation of MgAlON bonded refractories

Mario Sieger

Research output: ThesisMaster's Thesis


The aim of this work was to produce refractories with MgAlON as bonding phase. So far MgAlON has only been produced and investigated in small sized samples. It should be determined if it is possible to synthesize this bonding phase in samples with bigger dimensions. To form MgAlON during the burning procedure, samples with spinel as main component on the one hand and samples with alumina as main raw material on the other hand were used. First, a suitable binder has been determined. Partly the samples were produced in a continuous graphite kiln thus the binder should not contain sulfur and phosphor which could lead to contaminations on the kiln lining. The binder should not react with the aluminum nitride contained in the samples and green bodies should have sufficient stability. Dextrin was chosen as binder. Non-basic samples and samples with spinel as main component were produced and then burned in two different ways under reducing atmosphere. One aggregate for the burning was a continuous graphite kiln in which the samples were burned under a nitrogen atmosphere at 1650°C and the other aggregate was a muffle type furnace in which the samples were sintered under air atmosphere embedded in coke breeze at 1600°C. The influence on the phase composition (reflecting microscope, SEM, XRD) was investigated. The cold crushing strength, density, porosity, Young´s modulus and brittleness parameters of the samples as well as the resistance against oxidation and slag attack were examined. Samples with alumina as main component showed a matrix of aluminum rich spinel. MgAlON could not be verified. The nonbasic samples had a higher strength and density and and a higher characteristic length, indicating a lower brittleness compared to samples mainly made of spinel. They showed a better resistance against oxidation and slag infiltration. A lower strength and a higher brittleness could be verified in samples sintered in the muffle type kiln compared to samples burned in the continuous graphite kiln. The best oxidation resistance was shown by alumina samples of the graphite kiln. MgAlON as bonding phase could be found in spinel samples. If they were burned in the continuous graphite kiln whiskers could already be detected in the reflective microscope and the X-Ray diffractogram showed small peaks next to the peak of spinel. For samples sintered in the muffle type kiln MgAlON could not be spotted till the investigations with the SEM. The structure was loose and had a low strength. Thus samples produced this way could not be used for determination of mechanical parameters.
Translated title of the contributionProduction and investigation of MgAlON bonded refractories
Original languageGerman
  • Harmuth, Harald, Supervisor (internal)
  • Gschiel, Sabine, Co-Supervisor (internal)
Award date1 Jul 2016
Publication statusPublished - 2016

Bibliographical note

embargoed until 19-05-2021


  • MgAlON
  • nonoxides
  • refractories
  • continuous graphite kiln

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