Sintering study of Mag-Al Spinel synthesized via combustion synthesis using glycine as fuel

Abstract

The present work deals with the processing and sintering of phase pure Mag–Al spinel by auto-combustion process. Magnesium and aluminum nitrates have been used as the oxidizers and glycine as the fuel. Addition of glycine to the mixture of magnesium and aluminium nitrates results in a series of redox reactions to form a complex which subsequently crystallizes to form spinel at a lower temperature. Mag-Al spinel has been synthesized by varying metal to glycine ratio as 1:0.5, 1:1 and 1:2 and its effect on the spinel formation was studied. Variation of calcination temperature was done from 5000 C to 10000C for 1 hour and 2 hours and their XRD analysis were performed to identify the exact starting temperature for obtaining phase pure spinel. The phase pure Mag-Al spinel was formed at 700 °C, when using metal to glycine ratio as 1:2. However, the phase pure Mag-Al spinel formation took place at higher temperature in case of other metal to glycine ratios. Bulk density was achieved in the range 3.135 – 3.34. Apparent porosity in the range of (0 – 6.64) % was achieved.