In situ synthesis of NbB ₂ –Al ₂ O ₃ nanocomposite powder by mechanochemical processing

This research is based on the production of NbB2–Al2O3 nanocomposite powder using mechanochemical processing. For this purpose, a mixture of niobium, aluminium and boron oxide powders was subjected to high-energy ball milling. The structural evaluation of powder particles after different milling times was conducted by the X-ray diffractometry (XRD), scanning electron microscopy, and transmission electron microscopy. The results showed that during ball milling the Nb/Al/B2O3 reacted with a combustion mode producing NbB2–Al2O3 nanocomposite. The XRD analyses exhibited that the NbB2–Al2O3 nanocomposite was formed after 10 h milling time and increasing milling time up to 30 h had no significant effect other than refining the crystallite size. In the final stage of milling, the crystallite sizes of NbB2 and Al2O3 were estimated to be less than 50 nm.