Introduction to Heterostructured Materials : A Fast Emerging Field

Strong and tough materials are desired for lightweight, energy efficient applications such as electric cars and aerospace applications. Recently, heterostructures are found to produce unprecedented strength and ductility that are considered impossible based on the materials science in our textbooks. Such superior mechanical properties are enabled by a new scientific principle: hetero-deformation-induced (HDI) strengthening and work hardening. Heterostructured (HS) materials consist of heterogeneous zones with dramatic difference (> 100 pct) in flow stresses. The inter-zone interaction produces back stress in the soft zones and forward stress in the hard zones, which collectively produces the HDI stress. HS materials possess a significant synergistic effect where the integrated property exceeds the prediction by the rule of mixtures. Importantly, HS materials can be produced by current industrial facilities at large scale and low cost. The new materials sciences and promising applications are driving the fast development of the HS materials as an emerging field. There are many fundamental issues that need to be probed so as to effectively design HS materials for superior properties. To solve these issues, it requires collaborative efforts by the communities of experimental materials science and computational material science and mechanics.