Amorphous Microstructure Research Articles

Flexible noble-metal-free Fe-based metallic glasses as highly efficient oxygen evolution electrodes

Developing low-cost, and efficient oxygen evolution reaction (OER) electrodes with high flexibility is critical for hydrogen production. Here, flexible noble-metal-free Fe-based metallic glassy OER electrodes were fabricated via an electrochemical dealloying method combined with a dipping process. The sample requires a low overpotential of 258 mV to achieve a current density of 10 mA cm−2 in 1 M KOH solution, and the Tafel slope is 51.7 mV/dec. Galvanostatic test proved the excellent electrochemical stability of the electrodes. The highly efficient performance mainly originated from the high-energy disordered amorphous microstructure combined with the doping effect of nickel. Furthermore, the unique double-layer structure of the nanoporous surface covered with amorphous sheets increased the contact area of the samples. The ductile amorphous matrix together with the amorphous sheets tightly bonded on the nanoporous layer results in high flexibility of the electrodes. Our work provides a simple strategy to fabricate flexible amorphous OER electrodes.

Formation mechanism of Al-O intergranular amorphous phase toughened nanoscale ZrB2-ZrC composite coating synthesized by reactive plasma spraying

A new nanostructured ZrB2-ZrC composite coating with ZrB2-ZrC nanoscale eutectic and ZrB2+Amorphous microstructure was synthesized in situ by plasma spraying Zr-B4C-Al composite powder. The thermal analysis, quenching experiments and microstructure characterization were investigated and the formation mechanism of the bimodal in-situ microstructure was revealed. Al contributed to the liquid phase separation of molten droplets, which is the key to forming ZrB2+Amorphous microstructure. The formation of coating followed reaction-melting-liquid separation-deposition and solidification mechanism. The nanostructured ZrB2-ZrC composite coating with Al-O intergranular amorphous phase has excellent mechanical properties. The uniform nano-grains improved the hardness and the toughness of the ZrB2-ZrC eutectic. The ZrB2+Al-O amorphous microstructure obtained high toughness and the toughening mechanism was the crack deflection and crack branching caused by intergranular Al-O amorphous phase.

The temperature field characteristics and amorphous formation ability during the continuous casting process of Zr-based bulk metallic glass

This study utilized FLUENT dynamic mesh simulation technology to simulate the temperature field distribution characteristics during the continuous casting (CC) process of 5 mm thick Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 (Vit1) bulk metallic glass (BMG), analyzed and discussed the amorphous forming ability of the Vit1 BMG plate prepared through CC. The results indicate that during the CC process, the temperature gradient and cooling rate of Vit1 BMG plate decrease with increasing distance from the cooling copper block surface and prolonged solidification time. Even at the lowest cooling rate, it still remains significantly higher than the critical cooling rate (Rc) of Vit1 bulk amorphous alloy. The temperature variations recorded by the thermocouple during the alloy melt solidification process are in basic agreement with the simulation data. The experimental test and simulation results show that 5 mm thick Vit1 BMG slab can be prepared theoretically by continuous casting technology. Finally, XRD, DSC and TEM were used to analyze the amorphous formation ability and microstructure of the Vit1 BMG slab.

Mechanical properties and biocompatibility of multilayer systems based on amorphous SiN:H/SiCN:H layers on Ti6Al7Nb titanium alloy

Surfaces of metallic implants that replace diseased joints are bound to degrade over time under constant mechanical wear and corrosion, caused by the presence of biological fluids. Production of wear particles and toxic metal ions that follows can undermine both implant stability and patient’s health. To counteract this process multiple surface modifications have been proposed in scientific literature, ranging from simple nitriding to protective layers (e.g.: DLC, CN:H) and multilayer systems. This work presents a combined approach to outlined issue, using multi-staged plasma deposition with SiCN:H layer as a key component, realized using the MW CVD (Microwave Chemical Vapour Deposition) system. The study covers chemical characterization by EDS and FTIR analysis and measurements of relevant functional parameters, such as hardness, Young’s modulus, coefficient of friction, specific wear rate and wettability. Additionally, biocompatibility of modified surfaces are tested on MG-63 cells using Alamar Blue assay, flow cytometry and alkaline phosphatase (ALP) assay. Chemical and microscopic studies revealed amorphous cauliflower-like microstructures that have proven to be hydrogenated SiCN/SiN structures. The obtained layers are turned out to be biocompatible (>70 % of cell survival rate), additionally layers based on amorphous SiCN:H boost ALP activity due to combination of their chemistry and mechanical properties.

Glass and nanocrystalline phase formation in CuZrAg alloys: Insights from combinatorial thin film libraries studied by mapping synchrotron X-ray diffraction

We report detailed diffraction peak analysis and parameters indicative of the transition between fully amorphous microstructures and nanocrystal formation in sputter deposited thin film metallic glasses. Specifically, we fabricated ternary CuZrAg alloy films (2µm thickness) with a large compositional gradient on flexible, X-ray transparent polymer substrates in high vacuum conditions. The combinatorial libraries were subjected to point-by-point structural (XRD synchrotron radiation) and chemical (X-ray fluorescence spectroscopy) analysis, characterizing roughly 172 alloys. A strong correlation was found between peak symmetry and width, and early stages of crystalline phase formation. These nanocrystals are difficult to detect from the evolution of the peak position. In view of current literature, our data questions the recently claimed universality of the peak width as indicator of high glass forming ability. The addition of Ag significantly improves the poor glass formation of binary CuZr (36 alloys) under identical deposition conditions, as fully amorphous alloys are found for the majority of the investigated composition space. A thorough understanding of the microstructure of CuZrAg alloys on flexible substrates is highly relevant in view of favourable antibacterial properties and potential application as coatings for biomedical surfaces.

Microstructural characterization of nanocrystalline hexagonal boron nitride thin films deposited by ion-beam assisted pulsed laser deposition

In recent years, hexagonal boron nitride (hBN) thin films have garnered considerable attention across various fields, including electronics, anti-corrosion coatings, tribology, and optoelectronics. Boron nitride films produced via physical vapor deposition typically result in amorphous microstructure and suffer from issues such as cracking and delamination. The synthesis of crystalline hBN thin films typically demands higher processing temperatures, toxic gas precursors, and catalytic metal substrates. Hence, this research aims to produce crystalline hBN films at relatively lower temperatures without toxic gas precursors. hBN thin films were deposited on silicon (100) substrates at 600 °C using an ion beam-assisted pulsed laser deposition. The study explores the microstructural evolution and surface morphology of deposited films under different Ar:N2 gas mixtures (ranging from 0% to 100% N2) and varying ion beam energies (from 0 to 400 eV). Microstructural analysis showed the hBN nanocrystallite formation in films deposited with N2 content of 50% and higher and an ion beam energy equal to or exceeding 200 eV, and the crystallite size was measured to be ∼24±8 nm. Raman spectra, grazing incidence X-ray diffraction, and transmission electron microscopy confirm the presence of hBN phase in as-deposited films. Films deposited with an N2 content of ≥50% and ion beam energy of ≥200 eV showed improved crystallinity, increased island size, and density of hBN nanocrystallites. The addition of ion bombardment comparatively made films rougher due to grain growth and formation of larger hBN nanoislands, and surface roughness increased with an increase in N2 content and ion beam energy. The results indicate that the ion beam bombardment facilitates nanograin formation and improves the crystallinity of hBN films even at lower deposition temperatures, offering the promise of advancing their use into practical applications across various fields.

Novel titanium-based sulfur-containing BMG for PBF-LB/M

This paper investigates the additive manufacturing route for a novel glass-forming titanium-based sulfur-containing alloy of the composition Ti60Zr15Cu17S8\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\ ext{Ti}}_{60} {\ ext{Zr}}_{15} {\ ext{Cu}}_{17} {\ ext{S}}_{8}$$\\end{document}. This system is a promising candidate for medical devices since the lack of toxic components is combined with a high corrosion resistance and strength. Preliminary experiments and simulations show a general processability of bulk material by powder bed fusion technologies. TEM and XRD reveal an amorphous microstructure of laser-treated surfaces. Ultrasonic atomization is used to fabricate a flowable powder feed stock with spherical morphology and crystalline microstructure, which is suitable for processing in powder bed fusion. Correlations between detected crystalline phase formations and melt pool dynamics are revealed by SEM and EDX. It is shown that bulk samples with a high relative density and partially crystalline microstructure can be manufactured.

Empirical calibration method for the thermal simulation of Cu47Ti34Zr11Ni8 single tracks in laser powder bed fusion

Bulk metallic glasses (BMGs) are materials that, due to their amorphous microstructure, offer a unique combination of high strength, hardness, and elasticity, making them attractive for various applications. Using laser powder bed fusion (PBF-LB/M) enables overcoming the current limitations of BMGs in size and shape imposed by traditional manufacturing methods such as casting. Despite its potential, challenges such as porosity, (nano-) crystallization, and impurities affect the mechanical performance of additively manufactured BMGs. This study focuses on the Cu–Ti-based alloy Vit101, known for its higher strength and improved cost-effectiveness compared to Zr-based BMGs. In-situ high-speed pyrometry and thermal simulations of single tracks are employed to enhance the understanding of processing and controlling the thermal cycling of Vit101. The proposed experimental calibration is performed through an off-axis integration of the pyrometer, allowing for in-situ temperature measurements. The acquired data show sufficient congruence with the simulated cooling profiles. Minimal cooling rates in the range of 104 K/s were measured and simulated above the glass transition temperature, indicating a large leeway for further development of glass-forming alloys. Scan track widths are evaluated for validation, resulting in minor deviations between 0.47% and 3.17%. However, challenges emerge at high scanning speeds, leading to higher deviations attributed to balling phenomena, which are not considered in the numerical model.

Investigation of Cu-doped amorphous carbon film in improving corrosion resistance and interfacial conductivity of proton exchange membrane fuel cell

This study investigated Cu-doped a-C films prepared under a substrate bias gradually reducing from 120 to 60 V and different Cu target currents of 0, 0.15, 0.2, 0.3, 0.5 A, respectively, using closed field unbalanced magnetron sputtering physical vapour deposition technique. While the Cu-doped a-C film at the lowest Cu target current of 0.15 A (A0.15) remained an amorphous microstructure, Cu nanoprecipitates occurred at Cu target currents of 0.2–0.5 A. All the Cu-doped a-C films prepared exhibited good combination of corrosion resistance to a corrosive chemical mixture of 0.5 M H2SO4 + 5 ppm HF (as suggested by the corrosion current densities) and interfacial electric conductivity (as demonstrated by the interfacial contact resistance, ICR). Among all coatings, A0.15 showed the best corrosion resistance and interfacial electric conductivity, which is attributable to the precipitate-free Cu-doped amorphous microstructure. The measured current density of A0.15 was 1.95 × 10−7 A/cm2 at 0.6 V (vs. SCE) during potentiodynamic polarization, which was lower than that of the Cu-free a-C film at 7.34 × 10−7 A/cm2. The ICR value of A0.15 was 4.40 mΩcm2 at an assembly pressure of 1.4 MPa, which is about one third of the Cu-free a-C film. This study demonstrates a new deposition strategy combining Cu-doping and the control of substrate bias to improve the corrosion resistance and interfacial electric conductivity of a-C films for PEMFC.

Fe‐Based Amorphous Alloy Coatings: A Review

Fe‐based amorphous alloy coatings (Fe‐AACs) have exhibited appropriate corrosion and wear resistance and improved the performance of material surfaces. This study summarizes the advances related to Fe‐based amorphous alloys pertaining to their chemical compositions and manufacturing processes and their associated effect on the amorphous structure, microstructure, and properties. In particular, Fe‐based amorphous alloy coatings produced by laser cladding are investigated to study the effect of amorphous structure, partial crystallization, and composition on the microstructure, hardness, corrosion, and wear resistance of these coatings. In addition, the effects of laser parameters (power and scanning speed) on the geometric and metallurgical characteristics of produced amorphous coatings are also covered.

Electrodeposited MoxSyOz/Ni Tribological Coatings.

Deposition of molybdenum disulfide (MoS2) coatings using physical vapor deposition (PVD) and mechanical burnishing has been widely assessed for solid lubricants in space applications but still suffers from line-of-sight constraints on complex geometries. Here, we highlight one of the first demonstrations of electrodeposited MoxSyOz and MoxSyOz/Ni thin-film coatings from aqueous solutions of ammonium tetrathiomolybdate for solid lubricant applications and their remarkable ability to provide low coefficients of friction and high wear resistance. Characterization of the coating morphology shows amorphous microstructures with a high oxygen content and cracking upon drying. Even so, electrodeposited MoxSyOz can achieve low steady-state coefficients of friction (μ ∼ 0.05-0.06) and wear rates (2.6 × 10-7 mm3/(N m)) approaching those of physical vapor deposited coatings (2.3 × 10-7 mm3/(N m)). Additionally, we show that adding dopants such as nickel increased the wear rate (7.5 × 10-7 mm3/(N m)) and initial coefficient of friction (μi = 0.23) due to compositional modifications such as dramatic sub-stoichiometry (S/Mo ∼ 1) and expression of a NiOx surface layer, although doping did reduce the degree of cracking upon drying.

Effect of high moisture extrusion on the structure and physicochemical properties of Tartary buckwheat protein and its in vitro digestion

Tartary buckwheat is rich in nutrients and its protein supports numerous biological functions. However, the digestibility of Tartary buckwheat protein (TBP) poses a significant limitation owing to its inherent structure. This study aimed to assess the impact of high moisture extrusion (HME, 60 % moisture content) on the structural and physicochemical attributes, as well as the in vitro digestibility of TBP. Our results indicated that TBP exhibited unfolded and amorphous microstructures after HME. The protein molecular weight of TBP decreased after HME, and a greater degradation was observed at 70 °C than 100 °C. In particular, HME at 70 °C caused an almost complete disappearance of bands near 35 kDa compared with HME at 100 °C. In addition, compared with native TBP (NTBP, 44.53 µmol/g protein), TBP subjected to HME at 70 °C showed a lower disulfide bond (SS) content (42.67 µmol/g protein), whereas TBP subjected to HME at 100 °C demonstrated a higher SS content (45.70 µmol/g protein). These changes endowed TBP with good solubility (from 55.96 % to 83.31 % at pH 7), foaming ability (20.00 %–28.57 %), and surface hydrophobicity (8.34–23.07). Furthermore, the emulsifying activity (EA) and in vitro digestibility are closely related to SS content. Notably, extruded TBP (ETBP) obtained at 70 °C exhibited higher EA and digestibility than NTBP, whereas ETBP obtained at 100 °C showed the opposite trend. Consequently, HME (especially at 70 °C) demonstrated significant potential as a processing technique for improving the functional and digestive properties of TBP.

A strategy of fabricating efficient Mg2Ni nano-catalysts in Mg-Ni-Ag fibers and their excellent hydrogen storage properties at near-room temperatures

In this study, a new strategy was utilized to fabricate Mg-based hydrogen storage fibers with uniform elemental distribution and diameters of 30–50 μm. The in-situ formation of nano-precipitates in Mg85Ni14.8Ag0.2 metallic glass fibers was visually observed at varied annealing temperatures. It indicates the metastable Mg6Ni phase is formed from an amorphous microstructure initially. Then, the needle-like Mg2Ni nanoparticles precipitate at 140–160 °C and subsequently grow into spherical shapes. This results in the formation of the fiber structure with well-distributed nano-Mg2Ni particles. The alloy fibers can absorb H2 at only 40 °C, and the activation energy for hydrogenation is lowed to be 46.9 kJ/mol. The onset desorption temperature of hydride is reduced to 220 °C due to the improved the catalytic efficiency by uniformly distributed Mg2Ni nanoparticles. The abundant interfaces, as well as the shortened distance by micropores, serve as paths for the fast diffusion of H atoms.

“Tailoring thermal stability and in-plane magnetic anisotropy of CoFeB alloy thin films via growth conditions engineering”

The present work investigates the influence of growth conditions on the magneto-structural properties of magnetron-sputtered CoFeB alloy thin films. Films grown at room temperature (RT) are soft magnetic (coercivity <9 Oe), show amorphous microstructure, and possess a distinct uniaxial magnetic anisotropy (UMA) in the film plane. The amorphous microstructure and UMA persist up to a growth temperature (Ts) of 300 °C. CoFeB film grown at Si (100) substrate shows amorphous to crystalline phase transformation at Ts = 500 °C. In contrast, under the same growth conditions, the CoFeB film prepared on the SiO2 substrate maintains an amorphous structure up to Ts = 500 °C. The difference in the microstructures was explained in terms of the out-diffusion of B to the interfacial layer and segregation near the substrate for the films having crystalline and amorphous structure, respectively. On both the substrates Addition of W buffer layer facilitated the growth of smooth and nanocrystalline CoFeB films at Ts ∼300 °C. Upon crystallization, UMA evolution with a simultaneous increase in the coercive field is interpreted in terms of joint effect of random anisotropy model and surface/interface roughness-induced magnetization reversal mechanism. Unlike post-annealing, the CoFeB films prepared at high temperature shows superior thermal stability against crystallization. The relationship between the soft magnetic performance, UMA evolution, and thermal stability of CoFeB films with the growth conditions is established. The study reveals the role of growth condition engineering, to obtain CoFeB thin films with controlled microstructure and magnetic performance, which is crucial for designing the spintronics devices.

Crack-free wear resistance coating on carbon steel obtained by directed energy deposition of Fe-base partial amorphous powders

Laser Directed Energy Deposition of an Fe-base partial amorphous powder was carried out to study the feasibility of manufacturing partial amorphous coatings without macroscopic defects and high hardness values onto carbon steel substrates for wear resistance applications. Cold cracking can be avoided by preheating the substrate beyond 400 °C. Process parameters optimization can also guarantee fully dense coatings with hardness values above 800 HV. Results from x-ray diffraction correlate the high hardness to the crystallite size of the matrix phase and the presence of hardness enhancer phases, such as borides/carbo-borides and amorphous microstructure. Finally, wear resistance analyses on the coatings revealed an excellent response and confirmed the potential of combining this technology with Fe-base amorphous materials to increase wear resistance.

Raman spectroscopy investigation on amorphous polyetherketoneketone (PEKK)

We used Raman spectroscopy to analyze amorphous polyetherketoneketone (PEKK) and identified the conditions to obtain this material’s exploitable Raman spectrum. Our study assigns the vibrational modes observed from 100 spectra recorded on the amorphous PEKK’s surface, obtained by injection moulding. The peaks recorded on this polymer are specific to its amorphous microstructure. The vibration modes are similar to PEK and PEEK since they belong to the same family of materials, the polyaryletherketones. However, PEKK has a unique molecular structure with a ketone content of 67 % and an ether content of 33 %, resulting in an amplification or appearance of vibration modes associated with the ketone group’s vibrations and a decrease in the modes related to the ether group. This work provides a valuable database for those studying the microstructure of PEKK and its evolution with processing conditions and ageing.

Zircon Microstructures in Large, Deeply Eroded Impact Structures and Terrestrial Seismites

Abstract Extraterrestrial cratering was a critical component in the evolution of the early Earth, but discovery of very ancient and deeply exhumed impact structures remains elusive, as identification tools are in short supply. The recognition of such structures is hindered by post-cratering geological processes, whereby impact-induced features common in younger, upper-crustal craters may be lost. In this study, we make a detailed analysis of planar microstructures in zircons from four large, confirmed impact structures (Manicouagan, Rochechouart, Sudbury, Vredefort) preserved at different crustal levels, from two previously described non-impact seismites in SW Norway and northern Italy, and from the 3.0 Ga Maniitsoq structure in West Greenland. A total of ~3400 zircon grains were studied using exterior and interior scanning and transmission electron microscopy. We show for the first time that shocked zircons contain two successive, principally different types of planar microstructures, only one of which is diagnostic of impact. Closely spaced, contiguous microplanes (CP) are formed first, presumably by the shock wave. In Manicouagan and Rochechouart zircons the exterior CPs have ultrathin interior counterparts of straight dislocation arrays, as identified in Manicouagan zircon using transmission electron microscopy. They have the same close spacing and orientations as the exterior CPs and are abundantly decorated with tiny pores down to less than 50 nm across. These interior CPs are identical to shock-induced decorated, partly annealed amorphous planar microstructures in quartz (planar deformation features, PDFs) and are interpreted as such. The second type is open planar fractures (PF). They are widely and irregularly spaced and texturally younger than the CPs. They re-use and displace the CP orientations, which they cut in stepwise fashion. We interpret these PFs as formed by impact-induced seismic shaking in the wake of the shock wave. We confirm two previous reports of isolated planar fractures in zircons from non-impact seismites, showing that PFs per se are not impact-diagnostic. There are no CPs in any of these zircons. Zircons from different parts of the Maniitsoq structure contain CPs in various states of preservation besides PFs, corroborating that this very large and very deeply exhumed structure resulted from an extraterrestrial impact.

Microstructure, mechanical properties and thermal stability of Cr/WC nano-multilayered coating synthesized by ion beam sputtering

Cr/WC nano-multilayered coatings with fixed period ratio (Cr:WC=1:2) were synthesized by using ion beam sputtering method. The microstructure, mechanical properties and the thermal stability of coatings were investigated by X-ray diffraction, Scanning Electron Microscopy, Transmission Electron Microscopy and nanoindentation. Well-defined laminar amorphous microstructure and uniform monolayers, which consists of amorphous WC1-x and Cr, can be found in the as-deposited nano-multilayered coatings with series modulation period. Although the hardness of Cr/WC nano-multilayered coating increases with the increasing of modulation period, it is still lower than the value predicted by Hill model. Almost all the toughness of Cr/WC nano-multilayered coatings are lower than that of monolayer Cr coating, however, they are higher than that of monolayer WC coating, indicating that the addition of Cr and nano-multilayered architecture can improve the toughness of monolayer WC coating. Both microstructure and mechanical properties of Cr/WC nano-multilayered coatings were stable when the vacuum heat treatment temperature was lower than 400 °C. As the heat treatment temperature was 600 °C, some nanocrystalline W2C, W and WC1-x were enclosed in the amorphous WC sublayer which is beneficial to its hardness enhancement while it is harmful to its toughness. As the heat treatment temperature was 800 °C, the nano-multilayered structure was destroyed completely and its mechanical properties were seriously degraded.

Features of Tribooxidation of the High-Entropy Coating (AlCrZrTiTa)N during Dry High-Speed Cutting

The high-entropy PVD coating (AlCrZrTiTa)N, characterized by its high hardness (50–60 GPa), elastic modulus above 300 MPa, and high heat resistance up to 1300 °C, is used for coating cutting tools operating under extreme metalworking conditions. The nanostructured monolayer 3 μm PVD coating was deposited on cutting plates in the hybrid arc deposition PVD coater. The coating had an amorphous nanocrystalline microstructure with a grain size of about 10–50 nm. The samples of SS 304 steel were investigated during dry high-speed (600 m/min) cutting. Raman spectroscopy was used to study the formation of tribooxides on the tool surface at the running-in stage of the cutting. After 130 m of cutting, Cr2O3 oxide appears on the wear surface while other elements are bound with N atoms. When the cutting length is increased to up to 260 m, oxide Al2O3 · ZrO2 (mullite) and amorphous oxides TaO2 and CrO2 are formed. The method EELFS made it possible to determine the amorphous nanocrystalline structure of triboceramics based on CrO2 and Al2O3 · ZrO2. The nearest atomic surrounding of Cr-Cr, O-O, and Cr-O and their subsequent comparison with the available literature data allow us to calculate the equilibrium lattice constants of the CrO2 unit cell, which are equal to (a, b) = 4.3754 Å and c = 0.5927. The triboceramic films on the base of non-equilibrium mullite Al2O3·ZrO2 have an amorphous structure. In the first coordination sphere, the interatomic distances of Zr-O and Al-O were 1.79 and 1.89 Å. An accelerated adaptive reaction to extreme external stimuli, at the very beginning of the running-in stage, is established. The tribological adaptability of the high-entropy ultra-fine amorphous nanocrystalline coating under extremely loaded dry high-speed cutting is based on non-equilibrium phenomena: the partial oxidation of fragments of the nitride and dynamic formation of protective tribooxides, which have a good thermal barrier and frictional properties. These factors interact synergistically and determine the life of the cutting tool.

Crystalline and amorphous microstructure evolution of Zr-Cu-Al ternary alloys solidified in drop tube

High undercooling rapid solidification process has a significant impact on the solidified microstructure and mechanical properties of materials. In this study, particles with a diameter range between 100 and 1100 µm of ternary Zr50Cu40Al10 and Zr49Cu46Al5 alloys were prepared by a drop tube. The evolution process of particle-solidified microstructure with decreasing particle diameter was analyzed using XRD, SEM, and TEM. For Zr50Cu40Al10 alloy, the solidified microstructure in the particle diameter ranges of 200–1100 µm is composed of an amorphous phase and a primary B2-ZrCu high-temperature metastable phase. As the particle diameter reduces, the retained crystalline phase in the solidified microstructure decreases progressively, and the dendrite grain length gradually becomes finer. When the particle diameter is reduced to below 200 µm, the crystalline phase has completely disappeared, and the solidified microstructure evolves into a completely amorphous structure. For Zr49Cu46Al5 alloy, in the particle diameter range of 400–1100 µm, the solidified microstructure consists of primary B19'-ZrCu phase, a small amount of Cu10Zr7 phase and Zr14Cu51 phase. As the particle diameter reduces, a grain refinement phenomenon also occurs in the solidified microstructure and the dendritic morphology changes from equiaxed grain to rod-shaped dendrite. The amorphous phase appears when the particle diameter is lowered to 470 µm and solidified microstructure evolves into a completely amorphous structure as the particle diameter is reduced to 146 µm. The nanoindentation results show that the micromechanical properties of amorphous composite microstructures are superior to the single component composition of crystalline or amorphous phase for Zr50Cu40Al10 and Zr49Cu46Al5 alloys. The reinforcement effect on the amorphous phase is related to the content of the second crystalline phase. Moreover, under similar particle diameters, the mechanical properties of Zr50Cu40Al10 particles are always better than those of Zr49Cu46Al5 particles.