Preparation of blue ceramic pigments by reaction bonding

Autores: Rangel, E.R.|Baltazar, I.V.|Jurado, L.T.|Garcia, E.R.
Fuente: Munir, ZA; Ohji, T; Hotta, Y (Eds.) Innovative processing and manufacturing of advanced ceramics and composites. [s.l.] Wiley; ACERS, 2010. (Ceramic transactions; 212):
pp. 207-213

Synthesis of CoAl2O4 based blue ceramic pigments following the reaction bonding process was studied. An intense mechanical powder mixture of metallic cobalt and Al2O3 was prepared. The resulting powders from the milling period were heat treated in air in order to oxide; first the metallic cobalt with the oxygen present in the furnace atmosphere, and then, attain CoAl2O4 blue powders by a solid reaction between fresh CoO and initial Al2O3. The evolution of solid reactions was follows by TG, XRD, FT IR and UV Vis analysis. The obtained results from TG analysis indicate that Co oxidation starts at 200 degrees C and finishes at 700 degrees C. XRD patterns show that the formation of CoAl2O4 is completed at 850 degrees C. On the other hand, FT IR and UV Vis studies identify those different interactions between CoO and Al2O3 are taking place at temperatures in the region of 800 to 850 degrees C forming the CoAl2O4 spinel. Finally, the feature of obtained samples after solid reaction s is of an intense blue color.