a b s t r a c tNovel Cr-alloyed MoSi 2 -based nanocomposite coatings were successfully synthesized onto Ti-6Al-4V substrates by a double glow discharge plasma technique. The architecture of the nanocomposite coatings exhibited a hierarchical structure, consisting of equiaxed C40-MoSi 2 with a bimodal grain size distribution and strip-shaped Mo 5 Si 3 grains segregated to the boundaries of submicron MoSi 2 grains. The results showed that the toughness of the MoSi 2 -based nanocomposite coatings depended strongly upon their hierarchical structure and the magnitude of compressive residual stresses in the nanocomposite coatings.