MA-SHS of NbC and NbB2 in air from the Nb/B/C powder mixtures

When the Nb/B/C powder mixture with different molar ratios was mechanically activated by grinding for 60–150 min in a planetary ball mill and exposed to air, it self-ignited spontaneously and the self-propagating high-temperature synthesis (SHS) of NbC and NbB2 was induced. This mechanical activation assisted SHS (MA-SHS in air process) depended strongly on the particle size of Nb metal, the mixing ratio of Nb/B/C and the weight ratio of sample to balls. The product of NbC and NbB2 with fine, homogeneous microstructure is expected to be a promising candidate as precursor of NbC–NbB2 composites.