Microstructural and physical properties of magnesium oxide-doped silicon nitride ceramics

• Published in: Results in physics Vol. 6; pp. 82 - 83
• Main Authors: Sirota, V., Lukianova, O., Krasilnikov, V., Selemenev, V., Dokalov, V.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2016; Elsevier
• Subjects: Magnesium oxide; Silicon nitride; Structure; Structure; Magnesium oxide; Silicon nitride
• ISSN: 2211-3797; 2211-3797
• DOI: 10.1016/j.rinp.2016.01.005

Silicon nitride based ceramics with aluminum, yttrium and magnesium oxides were produced by cold isostatic pressing and free sintering. The phase composition of the starting MgO powder obtained by the novel technology has been studied. The effect of magnesium oxide content on the structure of the produced materials has been investigated. It was found, that obtained materials with 1 and 2wt.% of magnesium oxide and without it have a typical β-silicon nitride structure with elongated grains. Ceramics with 5wt.% magnesia has a duplex α/β-structure with elongated and equiaxed grains. Ceramics with 2wt.% magnesium oxide has a maximum density of 2.91g/cm3. The increases in magnesium oxide content upto 5% led to decrease in the shrinkage (from 16% to 12%) and density (from 2.88 to 2.37g/cm3).