SYNTHESIS OF AL2O3-NI COMPOSITE POWDERS BY CO-PRECIPITATION METHOD

The synthesis of micro-sized, uniformly distributed Al2O3-15Vol% Ni powders were studied through three step co-precipitation of hydroxides mixtures from proper solution, calcination at air atmosphere and final step of calcined powders in a carbon bed. Al and Ni hydroxide and amorphous phase were first obtained from their salt’s solutions through chemical co-precipitation method by adjusting pH. The precipitated powders were then calcined to obtain a mixture of their oxides as NiO and NiAl2O4 which were reduced in a carbon bed at various temperatures up to 1300. Proper temperature for calcination in air was determined through TG analysis; 900. SEM observation of powders after reduction, revealed micro-sized Ni particles, along with fin distribution of Ni and Al2O3 elements. XRD analysis of the calcined sample showed the presence of NiAl2O4 and NiO and the same analysis for the reduced sample confirmed the formation of Al2O3 and Ni.