Mechanochemical synthesis of Al 2O 3–TiB 2 nanocomposite powder from Al–TiO 2–H 3BO 3 mixture

Abstract

Alumina–titanium diboride nanocomposite (Al 2O 3–TiB 2) was produced using mixtures of titanium dioxide, acid boric and pure aluminum as raw materials via mechanochemical process. The phase transformation and structural characterization during mechanochemical process were utilized by X-ray diffractometry (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and thermogravimetric analyses (TG–DTA) techniques. A thermodynamic appraisal showed that the reaction between TiO 2, B 2O 3 and Al is highly exothermic and should be self-sustaining. XRD analyses exhibited that the Al 2O 3–TiB 2 nanocomposite was formed after 1.5 h milling time. The results indicate that increasing milling time up to 40 h had no significant effect other than refining the crystallite size.