Available online 11 January 2023
The heterogeneous magnesium (Mg) matrix nanocomposite with dispersed
soft phase exhibits high strength and toughness. Herein, the deformation
behavior and failure process were investigated to reveal the unique
mechanical behavior of the heterogeneous microstructure under compression. The extensive plastic deformation is accompanied by the flattening and tilting of the soft phase,
inhibiting strain localization and leading to strain hardening.
Moreover, a stable crack multiplication process is activated, which
endows high damage tolerance to the heterogeneous Mg matrix
nanocomposites. The final failure of the composite is caused by crack
coalescence in the shear plane along a tortuous path. The presence of
dispersed soft phases within the hard matrix induces a noticeable change
in mechanical response. Especially, the malleability of the
heterogeneous Mg matrix nanocomposite is two and ten times higher than
that of pure Mg and the homogeneous Mg matrix nanocomposite,
respectively. The current study provides a novel strategy to break the
trade-off between strength and toughness in metal matrix nanocomposites.