Breaking mixture rule of strength and ductility by interface induced nano-scale heterostructure in TA1/304 composites

Laminate composites offer an effective strategy to overcome strength-ductility trade-off by harnessing the synergistic properties of constituent metals. In the TA1/304 steel composite, a unique nano-scale heterostructure, introduced through the homogeneous and heterogeneous interfaces, breaks the mixture rule of strength-ductility. The composites achieve a high yield strength of 1050 MPa, exceeding that of its individual components due to remarkable grain refinement strengthening. A large uniform elongation of 28%, stems from formation of α′-/ϵ-martensite, stacking faults and the hetero-deformation induced stress strengthening in 304 steel layer, coupled with the activation of unusual <c+a> dislocations under high stress in TA1 layer.