<Abstrate>

A Ti-based bulk metallic glass matrix composite (BMGMC) with a homogeneous

distribution of dendrites and the composition of Ti₄₆Zr₂₀V₁₂Cu₅Be₁₇ is characterized

by a high tensile strength of ∼1640 MPa and a large tensile strain of ∼15.5% at room

temperature. The present BMGMC exhibits the largest tensile ductility and highest

fracture absorption energy under the stress–strain curve of all dendrite-reinforced

BMGMCs developed to date. Tensile deformation micromechanisms are explored

through experimental visualization and theoretical analyses. After tension, fragmentation

of the dendrites, rather than crystallization within the glass matrix and/or atom

debonding near the interface of dual-phase composites, is responsible for the high tensile

ductility. The subdivisions within the interior of dendrites are separated by shear bands

and dense dislocation walls, and local separation of dendrites under modes I and II prevails.

The multiplication of dislocations, severe lattice distortions, and even local amorphization

dominate within the dendrites. Good structural coherency of the interface is demonstrated,

despite being subjected to significant plastic deformation. Theoretical analyses reveal that

the constitutive relations elastic–elastic, elastic–plastic, and plastic–plastic of dual-phase

BMGMC generally correspond to the (1) elastic, (2) work-hardening, and (3) softening

deformation stages, respectively. The capacity for work-hardening is highly dependent on

the large plastic deformation of the dendrites and the high yield strength of the glass matrix.

The present study provides a fundamental basis for designing work-hardening dual-phase

BMGMCs exhibiting remarkably homogeneous deformation.
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