A Comparison Between in Situ-Provided Alumina-Spinel Composites by Gelcasting Using Magnesium Hydroxide and Acetate

In the present work, in situ production of Alumina-Spinel composite by gelcasting method is investigated. For this purpose, two different raw materials, magnesium hydroxide and magnesium acetate, were used and their properties were studied separately. The results of the sedimentation test show that the amount of dispersant agent in the suspension containing magnesium acetate was smaller than the suspension containing magnesium hydroxide. Also, the segments produced by magnesium hydroxide had higher mechanical properties than the ones produced by magnesium acetate. The effect of sintering time on the spinel phase constitution is examined by XRD. Finally, the existence of further porosities in the segments containing magnesium acetate was proven by SEM.