High entropy alloys (HEAs) have a wide range of applications across various fields, including structural engineering, biomedical science, catalysis, magnetism, and nuclear technology. Nanoscale HEA particles show promising catalytic properties. Nevertheless, attaining versatile composition control in nanoparticles poses a persistent challenge. This study proposes the use of pulsed laser ablation in liquids (PLAL) for synthesizing nanoparticles using equiatomic CoCrFeMnNi targets with varied preparation methods. We evaluate the impact of target preparation method on nanoparticle yield and composition as well as the magnetic properties of the nanoparticles. The elemental powder‐pressed heat‐treated target (HEA‐PP), identified as the most time‐efficient and cost‐effective, exhibits noticeable segregation and non‐uniform elemental distribution compared to ball milled hot‐pressed powder (HEA‐BP) and face‐centered cubic (FCC) single crystal (HEA‐SX) alloy targets. From all targets, nanoparticles (sizes from 2 to 120 nm) can be produced in ethanol with a nearly equiatomic CoCrFeMnNi composition and a FCC structure, showing oxidation of up to 20 at.%. Nanoparticles from HEA‐PP exist in a solid solution state, while those from HEA‐BP and HEA‐SX form core‐shell structures with a Mn shell due to inhomogeneous material expulsion, confirmed by mass spectrometry. HEA‐PP PLAL synthesis demonstrates 6.8 % and 15.1 % higher productivity compared to HEA‐BP and HEA‐SX, establishing PLAL of elemental powder‐pressed targets as a reliable, time‐efficient, and cost‐effective method for generating solid solution HEA nanoparticles.

STEM-EDX, HRTEM, SAED, XRD show CrFeCoNi Cu phase structure tunable by pulse duration: ns-LAL yields amorphous, ps-LAL crystalline HEA NPs. XPS, CV reveal surface composition changes; material effects govern scalable LFL amorphization.

In our search for an optimum soft magnet with excellent mechanical properties which can be used in applications centered around “electro mobility”, nanocrystalline CoCrFeNiGa_x (x = 0.5, 1.0) bulk high entropy alloys (HEA) were successfully produced by spark plasma sintering (SPS) at 1073 K of HEA powders produced by high energy ball milling (HEBM). SPS of non-equiatomic CoCrFeNiGa_0.5 particles results in the formation of a single-phase fcc bulk HEA, while for the equiatomic CoCrFeNiGa composition a mixture of bcc and fcc phases was found. For both compositions SEM/EDX analysis showed a predominant uniform distribution of the elements with only a small number of Cr-rich precipitates. High pressure torsion (HPT) of the bulk samples led to an increased homogeneity and a grain refinement: i.e., the crystallite size of the single fcc phase of CoCrFeNiGa_0.5 decreased by a factor of 3; the crystallite size of the bcc and fcc phases of CoCrFeNiGa—by a factor of 4 and 10, respectively. The lattice strains substantially increased by nearly the same extent. After HPT the saturation magnetization (M_s) of the fcc phase of CoCrFeNiGa_0.5 and its Curie temperature increased by 17% (up to 35 Am²/kg) and 31.5% (from 95 K to 125 K), respectively, whereas the coercivity decreased by a factor of 6. The overall M_s of the equiatomic CoCrFeNiGa decreased by 34% and 55% at 10 K and 300 K, respectively. At the same time the coercivity of CoCrFeNiGa increased by 50%. The HPT treatment of SPS-consolidated HEAs increased the Vickers hardness (H_v) by a factor of two (up to 5.632 ± 0.188) only for the non-equiatomic CoCrFeNiGa_0.5, while for the equiatomic composition, the H_v remained unchanged (6.343–6.425 GPa).

Ta/Ti/Ni/ceramic multilayered composites were successfully prepared by combustion synthesis. Laminated composites Ti–Ta–(Ti + 0.65C)–Ni–(Ti + 1.7B)–(Ti + 1.7B)–Ta–Ni-Ti and 3(Ti + 1.7B)–Ta–(5Ti + 3Si)–Ta–(Ti + 1.7B)–Ta–(5Ti + 3Si)–Ta–3(Ti + 1.7B) were combustion synthesized in an Ar atmosphere using (1) metallic foils (Ti, Ta, Ni) and (2) reactive tapes (Ti + 0.65C), (Ti + 1.7B), and (5Ti + 3Si), which, upon combustion, yielded ceramic layers as starting materials. The microstructure, crystal structure, and chemical composition of multilayered composites were characterized by SEM, EDX, and XRD. Their flexural strength was measured at 1100 °C. Upon combustion, Ta foils turned strongly joined with Ti ones due to the development of high temperature in the reactive layers yielding TiC_x and TiB_y. The formation of a liquid phase between metallic foils and reactive tapes and mutual interdiffusion between melted components during combustion favored strong joining between refractory metallic foils. Good joining between metals and ceramics is reached due to the formation of thin interfacial layers in the form of cermets and eutectic solutions.