ACTA

Synthesis of MgAl₂O₄ Spinel in MgO-Al₂O₃ and MgO-Al₂O₃-Al Systems via HPHT Sintering

Y. Rumiantseva^a, S. Lysovenko^b, A. Grzechnik^{c, d}, L. Wachnicki^e, T. Polczyk^{a, f}, A. Pieniążek^e, M. Gawron^a, P. Klimczyk^a, Y. Zhydachevskyy^e
^aŁukasiewicz Research Network - Krakow Institute of Technology, Zakopiańska 73, 30-418 Kraków, Poland
^bV. Bakul Institute for Superhard Materials of the National Academy of Sciences of Ukraine, 2 Avtozavodskaya Str., Kyiv 04074, Ukraine
^cJülich Centre for Neutron Science-4 (JCNS-4), Forschungszentrum Jülich GmbH, Jülich D-52425, Germany
^dInstitute of Crystallography, RWTH Aachen University, Aachen D-52056, Germany
^eInstitute of Physics, Polish Academy of Sciences, al. Lotników 32/46, Warsaw 02-668, Poland
^fFaculty of Chemistry, Jagiellonian University in Krakow, Gronostajowa 2, Kraków 30-387, Poland

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The synthesis of magnesium-aluminum spinel (MgAl₂O₄) by high-pressure-high-temperature sintering within the MgO-Al₂O₃ and MgO-Al₂O₃-Al systems has been investigated. The experiments were carried out at a pressure of 2 GPa and temperatures ranging from 400 to 1600°. Increasing the sintering temperature resulted in a higher MgAl₂O₄ content in both MgO-Al₂O₃ and MgO-Al₂O₃-Al systems. This, in turn, led to an increase in the hardness of the synthesized samples. The results suggest that high-pressure-high-temperature synthesis requires a sintering temperature of at least 1000° in a pressure range of 2.0-5.0 GPa to achieve optimal physical properties.

DOI:10.12693/APhysPolA.147.456
topics: magnesium-aluminum spinel, high-pressure-high-temperature (HPHT) sintering, chemical interaction, liquid phase sintering