Densification Study of Attritor Milled Magnesium Alummate Spinel

Pre-synthesization of magnesium aluminate spinel was done by mixing magnesium hydroxide and aluminium hydroxide in a molar ratio of MgO : Al2IO3 = 1:1 and then calcining the mixture at temperatures between 900° and 1600°C. X-ray diffraction patterns confirmed that only spinel phase was present above 1400°C. Pre-synthesized spinels were then attritor milled up to 6 h and the extent of milling was characterized by surface area Ameasurement. Milled and unmilled materials were isostatically pressed at 175 MPa and sintered between 1550° and 1650°C for 2 h and studied for densification. A maximum of 99% densification was achieved at a sintering temperature of 1650°C.