Two-glassy-phase bulk metallic glass with remarkable plasticity

Abstract

Using the computational-thermodynamic approach, the potential compositions of Zr-Cu-Ni-Al alloy system exhibiting the two-liquid miscibility phase equilibrium in the liquid temperature region have been identified. The resulting Zr base bulk metallic glasses show a microstructure of two microscaled glassy phases. The glass possesses a remarkable macroscopic plastic strain of 30% at room temperature. The gain of mechanical properties is attributed to the unique glassy structure correlated with the chemical inhomogeneity on the micron scale, the hard phases surrounded by the soft phases, leading extensive shear-band formation, interactions, and multiplication.

Microstructure and Mechanical Properties of Cu–Zr–Al Bulk Metallic Glass with Addition of Co

“…Similar results were also found in the ZrCu NiAl 10) and TiZrCuNiSn 11) alloy systems. However, in a recent work, Park et al 12) reported a nanoscale phase separation when adding above 15 at% Y to the CuZrAl based alloy, forming a composite of Cu-rich and Y-rich glassy phases, which does not exhibit any plastic strain upon deformation.…”

Effect of Al addition to Rapidly Solidified Mg-Cu-Rare Earth Alloys

“…(iv) Microalloying to produce the amorphous phase separation 19 . This was achieved in some BMGs by adding elements with a large difference in its mixing enthalpy when binding with the main elements of the alloy.…”

Designing Ductile Zr‐Based Bulk Metallic Glasses with Phase Separated Microstructure

“…[15,16] Due to similarity of the current composition with that of the Inoue's alloy, [19] the Poisson's ratio should not be greatly different. Thus, these three possibilities should be excluded.…”

“…[11][12][13][14] Further, based on the thermodynamic calculation, microscale phase separated Zr-based BMGs (Zr 63.8 Ni 16.2 Cu 15 Al 5 and Zr 65.8 Ni 15.8 Cu 8.4 Al 10 ) with a marked plasticity have been successfully developed by the authors. [15,16] And a unique mechanism operative in the phase-separated BMG, i.e, the effective hindering of the hard glassy phase on the propagating of shear bands, has been suggested. This indicates that by designing the compositions based on the thermodynamic calculation, some monolithic BMGs can deform plastically through the formation of phase-separated microstructures.…”