Function of magnesium aluminate hydrate and magnesium nitrate as MgO addition in crystal structure and grain size control of �?-Al2O3 during sintering

Bulletin of materials science

S Mukherjee¹  B N Samaddar²  P G Pal⁴  A K Bandyopadhyay⁴  Soumen Pal³ 

[1] School of Material Science and Technology, Jadavpur University, Kolkata 700 032, India$$School of Material Science and Technology, Jadavpur University, Kolkata 700 032, IndiaSchool of Material Science and Technology, Jadavpur University, Kolkata 700 032, India$$;Department of Metallurgical and Material Engineering, Jadavpur University, Kolkata 700 032, India$$Department of Metallurgical and Material Engineering, Jadavpur University, Kolkata 700 032, IndiaDepartment of Metallurgical and Material Engineering, Jadavpur University, Kolkata 700 032, India$$;Department of Ceramic Technology, Government College of Engineering and Ceramic Technology, Kolkata 700 010, India$$School of Material Science and Technology, Jadavpur University, Kolkata 700 032, India$$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$$School of Material Science and Technology, Jadavpur University, Kolkata 700 032, India$$School of Material Science and Technology, Jadavpur University, Kolkata 700 032, IndiaDepartment of Ceramic Technology, Government College of Engineering and Ceramic Technology, Kolkata 700 010, India$$School of Material Science and Technology, Jadavpur University, Kolkata 700 032, India$$;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: Sintering;    X-ray methods;    electron microscopy;    grain growth;    solid solubility.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

Chemically pure reactive alumina (ð›�?-Al₂O₃) which is commercially available was used for densification study in presence of widely accepted dopant MgO as additive. MgO was added both as spinel (MgAl₂O₄) forming precursor i.e. magnesium aluminate hydrate, and magnesium nitrate. Sintering investigations were conducted in the temperature range 1500â€�??1600°C with 2 h soaking. Structural study of sintered pellets was carried out by extensive XRD analysis. Scanning electron mode SEM images of the specimens were considered to understand the effect of both types of additions. Addition of MgO within and beyond optimum amount had some effect on development of microstructure of sintered bodies. Densification, around 99% ρ_th, with fine grain microstructure was achieved. These different types of additions caused two distinct changes in crystal structure of alumina-one small contraction and the other expansion of unit cell parameters.

【 授权许可】

Unknown