Effect of Al2O3 addition on texturing in a rotating strong magnetic field and densification of B4C. Issue 15 (15th October 2019)

• Record Type: Journal Article
• Authors: Fajar, Muhammad; Gubarevich, Anna; Maki, Ryosuke S.S.; Uchikoshi, Tetsuo; Suzuki, Tohru S.; Yano, Toyohiko; Yoshida, Katsumi
• Is Part Of: Ceramics international. Volume 45:Issue 15(2019)
• Page Start: 18222
• Page End: 18228
• Publication Date: 2019-10-15
• Subjects: Textured boron carbide -- Sintering -- Al2O3 -- Slip casting -- Densification -- Ceramic; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2019.06.032
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: The properties of ceramics can be improved by controlling the microstructure through texturing ceramics in a strong magnetic field. Fabricating dense boron carbide (B4 C) requires high temperature sintering, therefore sintering additives are often used in order to densify B4 C ceramics at lower temperatures. However, combined effect of texturing and sintering additives on densification of B4 C has not been made clear yet. Here we report the effect of alumina (Al2 O3 ) sintering additive on texturing in a strong magnetic field and densification of B4 C. Texturing was performed by rotating superconducting magnet at 12 T during slip casting process. Electron backscatter diffraction (EBSD) was used to observed the texturing projection. {0001} plane is clearly oriented in the plane parallel to rotating magnetic field. In addition, Lotgering factor was also calculated as quantitatively evaluation of texturing degree. Results on densification showed that addition of Al2 O3 successfully increased density of B4 C sintered by spark plasma sintering (SPS) at 1800 o C to 97.8%. Formation of aluminum borate (Al5 BO9 ) as secondary phase was detected by X-Ray diffraction (XRD). It is considered that the generation of Al5 BO9 assisted finer densification of B4 C ceramic. Textured B4 C sintered at 1700 o C by SPS without alumina addition exhibited the highest orientation of c-axis. Addition of alumina caused decrease in degree of orientation of c-axis.