A stabilized martensitic nucleation mechanism in TRIP-reinforced metallic glass composites with fractal structures

Fractal structures, inherent morphological characteristics of dendrites, play a crucial role in determining the mechanical properties of materials. In this work, a stable martensitic nucleation mechanism was revealed within TRIP (transformation-induced plasticity) reinforced bulk metallic glass composites with fractal structures. This finding emerged from a comprehensive synthesis of numerical simulations and experimental investigations. The identified stable martensitic nucleation mechanism initiates a stagewise interaction between martensitic transformation and shear band propagation, denoted as "martensite-induced shear bands" and "shear band-induced martensite". These deformation mechanisms, driven by fractal structural dendrites, are instrumental in achieving a desirable equilibrium between strength and ductility, which is advantageous over the traditional compromise of strength for enhanced plasticity. The profound understanding of stable martensitic nucleation and stagewise deformation mechanisms provides significant insights into the mechanical behavior of these materials, thereby facilitating the modulation of mechanical properties, such as through preloading treatments. Our findings advance the fundamental comprehension of fractal structure in TRIP-reinforced bulk metallic glass composites and provide a novel perspective for the design of high-performance materials.