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Quasi-static and dynamic compression were conducted on a new Ti-based dendrite/nanostructured matrix composite with an atomic composition of Ti58Zr12Ni6Nb13Be11. The composites exhibit high yielding strength of ∼1100 MPa, together with a considerable plasticity of 50% upon quasi-static compression at room temperature. Upon high-speed dynamic compression, a large plasticity of ∼15% can be obtained due to plasticity accommodation by abundant dislocations and profuse shear bands. A constitutive relationship is established by Johnson-Cook model, which is employed to predict the plastic flow behavior.

A novel light-weight and high-toughness in-situ dendrite/metallic glass matrix composites (MGMCs) with a composition of Ti58Zr12Ni6Ta13Be11 was designed. Quasi-static and dynamic compressive properties of MGMCs were investigated. The alloys showed excellent compressive properties of the maximum strength over 1.6 GPa and the total strain over 10% under the quasi-static loading. Under dynamic compressive loading, the compressive strength increased up to 1.9 GPa, whereas the total strain is nearly undiminished exhibited favourable plastic deformation. Deformation mechanisms related to the improvement of strength and ductility were investigated thoroughly by focusing on how ductile dendrites affected the initiation and propagation of deformation bands, accompanied with the localization of deformed bands and effects of ω phase precipitation, shear slipping, thermo softening, and melting. A constitutive relationship is obtained by modified Johnson-Cook plasticity model, which is applied to model the dynamic flow stress behavior. In addition, under dynamic compression, the strain rate effect of the yielding strength exerts distinctly positive strain rate sensitivity (SRS), which can be attributed to the dendrite-dominated plastic deformation fracture mechanism related to the significant accommodation of deformed bands and dislocation in the dendrites to the macroscopic dynamic deformation at relative strain rates.

Ni x Al 100− x ( x =70, 75, 80at.%) alloys were obtained by planar flow casting. The phase selection behavior of the alloys under different processing conditions was studied by using X-ray diffraction and electron microscopy. In contrast to the conventional casting ingots, the volume fraction of γ′-Ni 3 Al in the melt-spun ribbons increased and the volume fraction of β-NiAl decreased. In the alloys Ni 70 Al 30 and Ni 75 Al 25 , this trend is mainly due to the domination of the γ′ phase in the competition with the β phase, caused by the higher kinetic undercooling of the γ′ phase during rapid solidification. The effects of melt quenching on the phase compositions were explained on the basis of the kinetic analyses of nucleation and dendrite growth of coexisting intermetallics γ′(L1 2 ) and β (B2) phases.

Microstructure of rapidly solidified AlFeTi alloys with and without Ce addition was investigated by transmission electron microscopy. A new equation was given to calculate the relationship between the growth rate V , the ribbon temperature T and the solid thickness fraction f s . The results were consistent with the microstructure observation. It can be concluded that the substitution of AlTiCe ternary phase for the Al 3 Ti particles by introducing Ce into rapid solidification AlFeTi alloy resulted in the elimination of potent heterogeneous nucleants.