MgAl2O4�?����?-Al2O3 solid solution interaction: mathematical framework and phase separation of �?-Al2O3 at high temperature

Bulletin of materials science

S Mukherjee³  B N Samaddar²  P G Pal⁴  A K Bandyopadhyay⁴  Soumen Pal¹ 

[1] Department of Ceramic Technology, Government College of Engineering and Ceramic Technology, Kolkata 700 010, India$$School of Materials Science and Nanotechnology, Department of Metallurgical and Material Engineering, Jadavpur University, Kolkata 700 032, India$$Department of Ceramic Technology, Government College of Engineering and Ceramic Technology, Kolkata 700 010, IndiaDepartment of Ceramic Technology, Government College of Engineering and Ceramic Technology, Kolkata 700 010, India$$School of Materials Science and Nanotechnology, Department of Metallurgical and Material Engineering, Jadavpur University, Kolkata 700 032, India$$School of Materials Science and Nanotechnology, Department of Metallurgical and Material Engineering, Jadavpur University, Kolkata 700 032, IndiaDepartment of Ceramic Technology, Government College of Engineering and Ceramic Technology, Kolkata 700 010, India$$School of Materials Science and Nanotechnology, Department of Metallurgical and Material Engineering, Jadavpur University, Kolkata 700 032, India$$;Ex-emeritus Professor (AICTE), Department of Metallurgical and Material Engineering, Jadavpur University, Kolkata 700 032, India$$Ex-emeritus Professor (AICTE), Department of Metallurgical and Material Engineering, Jadavpur University, Kolkata 700 032, IndiaEx-emeritus Professor (AICTE), Department of Metallurgical and Material Engineering, Jadavpur University, Kolkata 700 032, India$$;School of Materials Science and Nanotechnology, Department of Metallurgical and Material Engineering, Jadavpur University, Kolkata 700 032, India$$School of Materials Science and Nanotechnology, Department of Metallurgical and Material Engineering, Jadavpur University, Kolkata 700 032, IndiaSchool of Materials Science and Nanotechnology, Department of Metallurgical and Material Engineering, Jadavpur University, Kolkata 700 032, India$$;Department of Ceramic Technology, Government College of Engineering and Ceramic Technology, Kolkata 700 010, India$$Department of Ceramic Technology, Government College of Engineering and Ceramic Technology, Kolkata 700 010, IndiaDepartment of Ceramic Technology, Government College of Engineering and Ceramic Technology, Kolkata 700 010, India$$

关键词: MgAl2O4 spinel;    Al2O3;    solid solution;    phase transformation;    X-ray diffraction.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

Although existence of MgAl₂O₄â€�?�ð�?��?-Al₂O₃ solid solution has been reported in the past, the detailed interactions have not been explored completely. For the first time, we report here a mathematical framework for the detailed solid solution interactions of ð›�?-Al₂O₃ in MgAl₂O₄ (spinel). To investigate the solid solubility of ð›�?-Al₂O₃ in MgAl₂O₄, Mgâ€�?�Al spinel (MgOâ€�?�ð�?��?�Al₂O₃; ð‘�?? = 1, 1.5, 3, 4.5 and an arbitrary high value 30) precursors have been heat treated at 1000°C. Presence of only non-stoichiometric MgAl₂O₄ phase up to ð‘�?? = 4.5 at 1000°C indicates that alumina (as ð›�?-Al₂O₃) present beyond stoichiometry gets completely accommodated in MgAl₂O₄ in the form of solid solution. ð›�? â†�?? ð›�? alumina phase transformation and its subsequent separation from MgAl₂O₄ has been observed in the Mgâ€�?�Al spinel powders (ð‘�?? > 1) when the 1000°C heat treated materials are calcined at 1200°C. In the mathematical framework, unit cell of MgAl₂O₄ (Mg₈Al₁₆O₃₂) has been considered for the solid solution interactions (substitution of Mg²⁺ ions by Al³⁺ ions) with ð›�?-Al₂O₃. It is suggested that combination of unit cells of MgAl₂O₄ takes part in the interactions when ð‘�?? > 5 (MgOâ€�?�ð�?��?�Al₂O₃).

【 授权许可】

Unknown