Ultra-high specific strength and deformation behavior of nanostructured Ti/Al multilayers.

Nanostructured Ti/Al multilayers with individual layer thicknesses of 10 nm and 100 nm were fabricated using a direct current magnetron sputtering system. The results showed that the Ti/Al multilayer with λ  =  10 nm exhibited ultra-high specific strength of 658.9 kN · m kg−1, greater than that with λ  =  100 nm and other existing multilayers. Such high specific strength of the Ti/Al multilayers endows them with strong potential for aerospace application. Moreover, depending on the stress concentration and barrier strength of the interface, layers of multilayer with λ  =  10 nm buckled severely, accompanied by the occurrence of pop-in, while a localized shear band formed in the multilayer with λ  =  100 nm. We also found that the occurrence of layer buckling had an effect on the hardness trend. [ABSTRACT FROM AUTHOR]