Melts of ${\mathrm{Pd}}_{42.5}{\mathrm{Cu}}_{30}{\mathrm{Ni}}_{7.5}{\mathrm{P}}_{20}$ (at. %) held under pressurized hydrogen are cast into bulk metallic glass (BMG) rods with fine ($20–30\mu \mathrm{m}$ diameter) pores uniformly dispersed. The low overall porosities $(<4\%)$ lead to only small reductions in Young modulus and yield strength, but to dramatically enhanced plasticity in compression: Rupture energy as high as $295\mathrm{MJ}{\mathrm{m}}^{-3}$ , compared to $16\mathrm{MJ}{\mathrm{m}}^{-3}$ for the pore-free BMG. The pores force the proliferation of shear bands below the overall failure stress, a process of interest for toughening BMGs, materials for which shear localization in deformation restricts structural applications.

High-entropy (H-E) alloys, bulk metallic glasses (BMGs) and high-entropy BMGs (HE-BMGs) were statistically analyzed with the help of a database of ternary amorphous alloys. Thermodynamic quantities corresponding to heat of mixing and atomic size differences were calculated as a function of composition of the multicomponent alloys. Actual calculations were performed for configurational entropy (S_config.) in defining the H-E alloys and mismatch entropy (S_s) normalized with Boltzmann constant (k_B), together with mixing enthalpy (DH_mix) based on Miedema’s empirical model and Delta parameter (d) as a corresponding parameter to S_s/k_B. The comparison between DH_mix–d and DH_mix– diagrams for the ternary amorphous alloys revealed S_s/k_B ~ (d /22)². The zones S, S′ and B’s where H-E alloys with disordered solid solutions, ordered alloys and BMGs are plotted in the DH_mix–d diagram are correlated with the areas in the DH_mix – S_s /k_B diagram. The results provide mutual understandings among H-E alloys, BMGs and HE-BMGs.

We found that a Ni-rich alloy with the composition of Ni₅₀Pd₃₀P₂₀ had high glass-forming ability. Bulk glassy alloy rods with diameters up to 7 mm can be easily formed by a water quenching method. Its mechanical properties were measured under compressive load. The bulk glassy alloy exhibits relatively high yield strength of 1780 MPa and good ductility as is evidenced from a large plastic elongation of 7.6% before final fracture. The elastic properties of this bulk glassy alloy were also investigated.

The present work was aimed to demonstrate the possibility of forming Fe₆₆Cr₁₀Nb₅B₁₉ metallic glass coatings by detonation spraying and analyze the coating formation process. A partially amorphous Fe₆₆Cr₁₀Nb₅B₁₉ powder with particles ranging from 45 µm to 74 µm in diameter was used to deposit coatings on stainless steel substrates. The deposition process was studied for different explosive charges (fractions of the barrel volume filled with an explosive mixture (C₂H₂ + 1.1O₂)). As the explosive charge was increased from 35% to 55%, the content of the crystalline phase in the coatings, as determined from the X-ray diffraction patterns, decreased. Coatings formed at explosive charges of 55–70% contained as little as 1 wt.% of the crystalline phase. In these coatings, nanocrystals in a metallic glass matrix were only rarely found; their presence was confined to some inter-splat boundaries. The particle velocities and temperatures at the exit of the barrel were calculated using a previously developed model. The particle temperatures increased as the explosive charge was increased from 35% to 70%; the particle velocities passed through maxima. The coatings acquire an amorphous structure as the molten particles rapidly solidify on the substrate; cooling rates of the splats were estimated. The Fe₆₆Cr₁₀Nb₅B₁₉ metallic glass coatings obtained at explosive changes of 55–60% showed low porosity (0.5–2.5%), high hardness (715–1025 HV), and high bonding strength to the substrate (150 MPa).