Microstructure Of Dispersion Research Articles

Biological response guided by hybrid additive manufacturing for Ti6Al4V titanium alloy

This research evaluates the cellular response from Ti6Al4V scaffolds fabricated by hybrid additive manufacturing (AM) with the goal of improving bone tissue growth and biocompatibility of titanium implants. Since cellular adhesion and viability are subject to microstructure, hybrid AM was sought to dictate biological response by creating a dispersed and gradient microstructure within implants. The objective was to evaluate the effect of gradient microstructures within Ti6Al4V scaffolds on cellular metabolic activity. Gradient microstructure was incorporated within scaffolds by hybrid AM coupling directed energy deposition (DED) with interlayer milling. The cellular response from the scaffolds was evaluated using cell viability assays in two stages: the Ti6Al4V powder used for DED was first evaluated, followed by the fabricated scaffolds. Cell viability on hybrid AM scaffolds was compared with as–printed, i.e., DED-fabricated and annealed Ti6Al4V scaffolds. The cell viability assays demonstrated that Ti6Al4V powder was non-toxic as cells cultured with powder exhibited metabolic activity similar to cells in growth media without powder. The cell viability study on scaffolds indicated, on average, cell adhesion on hybrid AM scaffolds outperformed as–printed and annealed scaffolds. This study provides preliminary data demonstrating the use of hybrid AM to dictate cell activity. A larger sample set would be required in future work to understand the effects of grain refinement through coldworking on biological response.

Determining technological parameters for obtaining ta15 titanium alloy blanks with improved mechanical characteristics using the electron-beam 3D printing method

The object of this study is the process of electron beam 3D printing of articles made of TA15 titanium alloy powder. Peculiarities of the structure and properties formation of alloy blanks, obtained by this method have been described. Influence of process parameters (electron beam power and geometric scanning parameters) on the characteristics of the material were considered. Step of displacement of the beam trajectory changed from 0.1 to 0.25 mm with an interval of 0.05 mm. Specific energy of the electron beam varied from 20 to 70 J/mm3 for every trajectory displacement step. The macrostructure was examined visually while the microstructure was studied by optical microscopy. Mechanical properties were determined by uniaxial tension and impact bending tests. It was established that depending on the 3D printing parameters the macrostructure of most samples is dense but with unfavorable parameters non-fusions or shrinkage porosity defects may form. The microstructure of the dendritic type has an α´+β lamellar-acicular morphology, its dispersity and shape of α´–phase areas vary depending on the process parameters. A scanning step of 0.2 mm and a beam energy of 40 J/mm3 allows obtaining a dispersed microstructure in which there are no non-fusions and shrinkage micropores. The value of the Rm is 27 %, and the R0.2 is 24 % higher than that of the alloy obtained by the conventional technology of electron beam melting. The A5 is 3.2 times higher. However, impact toughness of the sample with dendrite unfavorable orientation to the direction of load applying may be lower compared to conventional technology. The results could be used for devising commercial technology of high strength titanium alloys parts produced by 3D printing

Microstructure and mechanical properties of oxide dispersion strengthened FeNiMnCr high-entropy alloy fabricated by spark plasma sintering

High-entropy alloys (HEAs) strengthened by dispersed oxide nanoparticles are considered potential structural materials used in advanced nuclear reactors. Herein, a novel Y-Si-O nanoparticle-strengthened near-equiatomic FeNiMnCr HEA was prepared via the powder metallurgy method. Microstructural characterizations revealed that the oxide dispersion-strengthened (ODS) FeNiMnCr HEA consisted of the face-centered cubic (FCC) matrix and high-density Y-Si-O nanoparticles (Y2SiO5 and Y2Si2O7). The average diameter and volume fraction of the nanoparticles were counted to be 21.3 nm and 1.02%, respectively. The grain size was reduced from 10.13 μm of the FeNiMnCr HEA to 0.79 μm of the ODS FeNiMnCr HEA. The ODS FeNiMnCr HEA showed a yield strength of 1125 MPa, an ultimate tensile strength of 1137 MPa, and a moderate elongation of 8.3% at room temperature. At 500°C, the ODS FeNiMnCr HEA also had a high yield strength of 662 MPa. Theoretical calculation showed that the high strength of the ODS FeNiMnCr HEA was mainly due to the grain boundary strengthening, dislocation strengthening, and precipitation strengthening.

Understanding the Subsurface Microstructure and Thermal Behavior of Model Oxide Dispersion Strengthened Alloys Through FIB_SEM and TEM

AbstractA potential but an underexplored application of FIB_SEM is its ability to image the subsurface microstructure and capability for an associated chemical analysis. In this article, agglomerated microstructures of two model oxide dispersion strengthened alloy systems, consisting of ZrO2 and Y2O3 dispersions, are evaluated to understand its elevated temperature behaviors. The systems under evaluation are relevant as candidate nuclear structural materials for next-generation fast breeder reactors, and FIB_SEM technique is effectively used along with TEM and EDS for a comprehensive understanding of the material microstructure, and the results are discussed. Distinct microstructures are observed for the two systems with a difference in crystallite size distribution and presence of micron-sized dispersoids in Y2O3. The varied behavior of dispersoids is discussed in terms of its pre-annealing microstructures, and the superiority of ZrO2 over Y2O3 as a dispersoid for ODS alloys is emphasized.

The effect of modification with nanocompositions on the structure and properties of foundry silumins


 Abstract. Problem. The difficulty of solving the problem lies not only in the improved quality of casting alloys, but also in the development of recommendations for achieving stability of the chemical composition, refining the structure, and increasing the mechanical and technological properties of castings. Goal. The goal of the work is to achieve a stable dispersed structure and increase the complex of mechanical properties of foundry silumins. Methodology. Based on the Al – Si influence diagram, the choice of cast aluminum alloys for modification with nanocompositions is substantiated. The technology of modification with nanodisperse compositions consisted in introducing powders of the complex nanomodifier Mg2Si+SiС into the aluminum melt. A mixture of Mg2Si+SiC nanopowders with a particle size of 50...100 nm, obtained by plasma chemical synthesis, was mixed for several hours in a special attritor with successive pressing of modifier tablets on an automatic press. Results. The technological process of modifying aluminum melts with a complex modifier was developed, the temperature and time parameters of the process were determined. Brinell hardness was measured on samples of AL4 and AL4C alloys, 25x25 mm in size. As a result of the obtained data, it is observed that in the modified samples of the AL4 alloy, the hardness increased by 6.9%, and in the AL4C samples – by 4.8%. The obtained hardness measurement data are consistent with the results of testing the strength properties of alloys before and after modification. Originality. In the modified alloys, a higher fluidity than in the initial state and a homogeneous dispersed microstructure were obtained. Practical value. In the modified alloys, an increase in strength properties was achieved: σv by 9 - 10%; σ0.2 by 11-12%, while maintaining the level of plasticity. The impact strength of modified alloys is significantly increased by 20-30%. As a result of the conducted studies of the structure and properties of cast alloys AL4 and AL4C, the effect of modification with nanodisperse compositions was confirmed.

Effect of Y2O3 nanoparticles on enhancing microstructure and mechanical properties of oxide dispersion strengthened W alloy

Dispersion of oxide nanoparticles in W, leading to the dispersion strengthening of W alloys, has emerged as a viable strategy to overcome the brittleness of W. In particular, the introduction of stable Y2O3 as a secondary phase refines the grain and enhances the densification of W, leading to an increase in the density of sintered alloy. Thus, analyzing the composite effects of Y2O3 on the alloy, which has homogeneous dispersion of Y2O3 nanoparticles, can allow enhanced mechanical properties of the W-Y2O3 alloy. However, to date, most studies have focused on synthesis methodology for nanocomposites, which is advantageous to grain refinement and dispersion. It is worth paying attention to the interaction in the W-Y2O3 system, such as the ternary oxide system (W-Y-O) with a low eutectic temperature and the possibility of liquid-phase sintering, which has been reported a few. In this study, the effect of Y2O3 nanoparticles on the microstructure and micro-Vickers hardness of W was experimentally evaluated. W-Y2O3 alloys with precisely controlled compositions from 1 wt% to 10 wt%Y2O3 were successfully fabricated using an ultrasonic spray pyrolysis process and a subsequent spark plasma sintering. The proposed process yielded Y2O3 nanoparticles with uniform dimensions and distributions even after sintering. Furthermore, the formation of Y2WO6 and a liquid-phase sintered structure, as products of the interaction between W and Y2O3 depending on the Y2O3 fraction, were observed, and thermodynamical formation routes were suggested. Evidently, the W-2wt%Y2O3 sintered alloy, with uniformly dispersed Y2O3 nanoparticles (<50 nm), exhibited an improved hardness of 7.21 ± 0.15 GPa, as the W grains were refined to approximately 760 nm, and their density increased to 96.48%.

Predicting the particle-agglomeration effect on the equivalent mechanical properties of dispersion nuclear fuel by machine learning

The optimal design of dispersion nuclear fuel necessitates precise correlations between the particle distribution and mechanical properties, which can be established by combining the numerical method, data-driven technique, and machine learning model. In this study, we developed an automated high-throughput workflow to rapidly generate massive number of dispersion nuclear fuel meat models with different particle distributions, and further built the machine learning database for predicting the crucial mechanical properties. Effects of the particle-agglomeration behavior on mechanical properties of the dispersion fuel meat were analyzed in length. The automated workflow includes the entire parametric modeling, parallel computation and post-processing of simulated results, through which we can calculate the equivalent elastic modulus and the maximum Mises stress of the dispersed microstructure with randomly distributed fuel particles. The Fourier distribution function is utilized to characterize the random particle distribution configuration. The analysis suggests that the particle distribution configuration, the volume fraction and the number of agglomerate particles are the crucial factors determining the performance of dispersion nuclear fuel. Furthermore, through utilizing the database constructed by high-throughput computing, the Gaussian process regression algorithm was successfully applied to accurately forecast the mechanical properties in the dispersion fuel meat. This work lays a foundation for optimizing the design of high-performance dispersion nuclear fuel, quickly estimating mechanical properties of composite structures containing randomly dispersed particles, and further extending to analogous systems.

Influences of adding Y2Ti2O7 and HfH1.98 nanoparticles on the microstructure and mechanical properties of oxide dispersion strengthen steels

Adding Y2O3 will make Al-containing oxide dispersion strengthened (ODS) steels produce coarse Y-Al-O particles, which deteriorates their mechanical properties. Herein, Y2Ti2O7 nanoparticles and Hf hydride nanoparticles (NPs) were successfully prepared by hydrogen plasma-metal reaction (HPMR) method and added together in the Fe-Cr-Al ODS steel to replace the traditional Y2O3 NPs. The microstructure of matrix and oxide in ODS steels has been characterized by scanning transmission electron microscopy (STEM) and high resolution transmission electron microscopy (HRTEM). The oxide NPs in FHYT-0.6 (Fe-14Cr-4.5Al-2 W-0.35HfH1.98–0.6Y2Ti2O7, wt%) are made of Y2Ti2O7 (semi-coherent with the matrix and about 10 nm) and HfO2 (incoherent with the matrix and about 26 nm). The size of oxide dispersoid in FHYT-0.6 is reduced to 8.8 nm and the number density is greatly increased to 9.4 × 1023 m−3 compared with FTYT-0.6 (Fe-14Cr-4.5Al-2 W-0.35Ti-0.6Y2Ti2O7, wt%) and FTY-0.6 (Fe-14Cr-4.5Al-2 W-0.35Ti-0.6Y2O3, wt%). The tensile strength at room temperature of FHYT-0.6 is 1194 MPa, which is 24.1 and 14.1% higher than the FTY-0.6 and FTYT-0.6, respectively. Our work has proved that the mechanical properties of the alloy can be significantly improved by adding Y2Ti2O7 and HfH1.98 NPs, which provides a new idea for manufacturing high-performance ODS steels.

Microstructure and Tribological Behavior of Cr-Mn-N Steel with Age-Hardened Near-Surface Layer including CrN and Fe2N Particles Intended for Use in Orthopedic Implants

This paper presents the results of a study of 17%Cr-19%Mn-0.53%N high-nitrogen austenitic stainless steel with a 25 µm thick dispersion-hardened near-surface layer intended for orthopedic applications. It was modified using a mechanical–thermal treatment (MTT) that included both friction processing and subsequent electron beam processing. The friction processing enabled the formation of a microstructure with a high dislocation density and strain twins, and it also initiated strain aging in the near-surface layer. At this stage, the hardening was achieved via the formation of CrN particles coherent to the matrix with the face-centered cubic (FCC) lattice and via the relaxation of internal stresses. After electron beam processing, the volume fraction of the nanodispersed phases increased. In the near-surface layer, a highly dispersed microstructure with a grain size of 3 μm, reinforced with CrN and Fe2N nanoparticles, was observed using transmission electron microscopy. The MTT increased the microhardness of the surface layer, and this contributed to the enhancement in both the H/E and H3/E2 ratios. This indicated an improvement in the crack resistance of the steel under frictional loads. The MTT also enhanced both the yield point (up to 580 MPa) and the wear resistance (by 50% to 100%, depending on the applied load) compared with those of the same steel after it had undergone quenching. In addition, the wear resistance was many times greater than that of the Ti-6Al-4V alloy typically used for manufacturing orthopedic implants. After the MTT, the properties of the near-surface layer of the steel indicated its suitability for biomedical applications.

Investigation on microstructure and tensile shear properties of 9Cr oxide dispersion strengthened steel resistance spot welded joint

Resistance spot welding is employed to join the 9Cr oxide dispersion strengthened steel and the effects of different welding parameters are studied. Within the ranges of parameters used in this experiment, the failure load and energy increased from 4.3 kN, 1.0 J to 6.8 kN, 7.5 J as the welding current increased, while as the electrode force increased, the failure load and energy first decreased from 6.8 kN, 3.8 J to nearly 4 kN, 1.2 J, then remained stable. As the welding current exceeded 12.8 kA, the failure mode changed from pull out failure along the fusion line to the pull out failure along the fusion line partially and base metal partially. The welding current and electrode force strongly affect the mechanical properties and fracture mode of the joint.

Impact of residual cementite on inhibition of CO2 corrosion of mild steel

A thick cementite skeleton exposed on a ferritic-pearlitic C1018 steel surface after pre-corrosion significantly compromised inhibition efficiency. However, this detrimental effect was insignificant for a lower carbon X65 steel with dispersed cementite microstructure, due to the insignificant amount of cementite that remained on its surface after pre-corrosion. After normalizing the increased cathodic area in the presence of residual cementite back to original area, both anodic and cathodic reactions were inhibited to the same extent as on bare steel with a sufficient inhibitor concentration. However, the detrimental effect of cementite cannot be completely eliminated due to its galvanic coupling effect.

Investigation on the Microstructure, Unconfined Compressive Strength, and Thermal Conductivity of Compacted CDG Soil by MICP Treatment during Curing

As an eco-friendly treatment method, the microbially induced calcite precipitation (MICP) approach has been widely adopted in sand, but its use on compacted fine-grained soils remains scarce. In this study, compacted completely decomposed granite (CDG) soils at both the dry and wet side of the optimum water content (dry- and wet-of-optimum) were treated by the MICP approach, using a bacterial suspension and chemical reagents at fixed concentrations. After various curing periods, the microstructure (by scanning electron microscopy testing), the produced calcium carbonate content, the unconfined compressive strength (UCS), and the thermal conductivity were analyzed through a series of laboratory tests. The testing results indicate that the sample at dry-of-optimum exhibits a flocculated microstructure, while a dispersed microstructure is shown for the sample at wet-of-optimum. The calcium carbonate content increases with the curing period until reaching a stable value at around 6 days’ curing. After 6 days’ curing, the MICP process is relatively static, without significant amounts of calcium carbonate produced. With this treatment, the UCS of the sample is improved, where higher efficiency was observed for the sample at wet-of-optimum conditions. The variation of UCS for the MICP-treated samples with respect to the curing period follows the same trend as that of calcium carbonate content. At dry-of-optimum, the air-solid phases control the heat transfer in the MICP-treated samples with a discontinuous water phase, leading to insignificant effects of the MICP treatment on the thermal conductivity. In contrast, the water-solid phases dominate the heat transfer in the MICP-treated samples at wet-of-optimum, resulting in variation of the thermal conductivity with the curing period similar to that for the calcium carbonate content.

Hot Ductility, Homogeneity of the Composition, Structure, and Properties of High-Strength Microalloyed Steels: A Critical Review

High-strength microalloyed steels are widely used in various branches of technology and industry due to the simultaneous combination of high indicators of strength, ductility, fatigue, corrosion resistance, and other service properties. This is achieved due to the reasonable choice of the optimal chemical composition and parameters of temperature-deformation treatment of steel that provide a synergistic effect on the dispersed microstructure and characteristics of excess phase precipitates, which control the achievement of these difficult-to-combine properties of rolled products. Additionally, the improvement of the level and stability of these properties, as well as the prevention of the occurrence of defects, is largely determined by the indicators of the homogeneity of the composition, structure by volume and manufacturability of the metal, and primarily hot ductility, which are controlled by the presence of precipitation of excess phases, including microalloying elements. In accordance with the circumstances noted, in the present review, a generalization, systematization, and analysis of the results of the studies are conducted on the effect of phase precipitates on the hot ductility and homogeneity of composition and structure, depending on the chemical composition and parameters of the temperature-deformation treatment of steel.

Observations and simulations for phase separation process of immiscible Fe50Sn50 alloy droplets placed on a chilling surface

Liquid phase separation and microstructure evolution mechanisms of immiscible Fe50Sn50 alloy droplets placed on a chilling surface have been investigated by both arc melting experiments and lattice-Boltzmann simulations. The pattern selection of phase-separated morphologies strongly depended on the sample diameter. With the reduction in sample size, phase separation time was shortened, two-layer macrosegregation morphologies first transformed into intermediate phase-separated morphologies and finally changed into a homogeneously dispersed microstructure. The farther away from the sample bottom the longer the phase separation time and the larger the Sn-rich phase. A heat transfer equation was proposed to analyze the temperature field characteristics of Fe50Sn50 alloy droplets placed on the surface of a water-cooled copper mold. Theoretical analyses revealed that the sample gradually cooled from the bottom to the top of the sample. There existed a relatively high temperature gradient of several hundred Kelvins per millimeter between the top and the bottom of the arc melted sample, which induced the occurrence of an extremely intense Marangoni convection. The smaller the sample size the larger the temperature gradient and the greater deviation-degree of Fe-rich zone in two-layer macrosegregation structure from the bottom of the sample. The simulated two-layer phase-separated morphology agreed well with the experimental observations. Numerical simulations demonstrated that the effect of Marangoni convection on the phase separation was significantly stronger than the Stokes motion, and Fe-rich globules with a larger density tended to move upward to form a Fe-rich zone deviating from the bottom of the sample.

Thixotropic deformation behavior, rapid spheroidization and solid-liquid homogenization of semi-solid Al0.8Co0.5Cr1.5CuFeNi HEA with multilevel microstructure

In this paper, powder metallurgy-rapid heating and isothermal-holding (PMRHI) method was proposed to realize the rapid spheroidization and suppression of solid grain coarsening in semi-solid Al0.8Co1.5Cr0.5CuFeNi HEA. The thixotropic behavior and microstructure after PMRHI were investigated. Shear thinning effect exists during thixotropic deformation. The bimodal characteristics of flow stress degenerates with the proceeding of solid grain sliding (SS) and flow of liquid incorporating solid grains (FLS), indicating solid-liquid homogeneity and stable thixotropic deformation. The solid-liquid distribution homogeneity can suppress voids and hot tearing caused by liquid film channels. In multilevel semi-solid microstructure, the orientation relationship between solidified liquid phase and solid grain is approximately Kurdjumov-Sachs relationship, fine Al-Ni and Fe-Cr rich spinodal plates and nano Cu precipitates are formed in solid grain. The rapid spheroidization is realized due to initial dispersed powder metallurgy microstructure. After the steady thixotropic deformation of 1225 °C /0.05 s−1, mechanical properties were significantly improved.

Development of technology for production of new materials on traditional wide-strip hot rolling mills using modern methods of numerical and physical modeling. Part 2

The first part of the article presents a modern approach to the technology development for the manufacture of hot-rolled steel with characteristics that exceed the passport values of the equipment of traditional hot strip mills using based on the widespread use of mathematical and simulation methods. The stages of the laboratory experiment and the carried-out investigations are described. In the second part, the results of industrial implementation and their comparison with the results of a laboratory experiment are considered. According to the developed modes of hot rolling on the hot strip mill 2000, industrial batches of rolled products were produced using the technology of direct quenching from rolling heating. The resulting microstructure is a matrix of lower bainite with a share of upper bainite, retained austenite, and Fe3Mo3C carbide phase in total no more than 10 %. The formed structure provides in rolled products a strength of 1075 MPa and a relative elongation of at least 10 %. Due to the formation of a dispersed bainitic microstructure, the tension diagram is characterized by a degenerate yield plateau. The developed deformation rolling mode in the roughing and finishing groups of stands makes it possible to form elongated &ldquo;fritter-like&rdquo; grains with a grain length to thickness ratio of 2.5&ndash;3.0 before accelerated cooling, due to which the KCV&ndash;40 impact strength values significantly exceed the consumer requirements (170&gt;27 J/cm2). Using modern numerical simulation methods, the parameters of accelerated cooling on the run out table and the downcoiler settings of the hot strip mill were determined, which made it possible to achieve the desired temperature state of the strip and defect-free coiling from the first piece. The convergence of the results of laboratory and industrial experiments is shown.The research was carried out within the framework of the program of strategic academic&nbsp;leadership of the Russian Federation "Priority-2030", aimed at supporting the development&nbsp;programs of educational institutions of higher education, the scientific project PRIOR/SN/NU/22/SP5/26 "Creation of innovative digital tools for the use of applied artificial&nbsp;intelligence and advanced statistical analysis of big data in technological processes for the&nbsp;production of metallurgical products.

Microstructure, mechanical and tribological properties of oxide dispersion strengthened CoCrFeMnNi high-entropy alloys fabricated by powder metallurgy

Developing materials with superior strength and wear resistance has always drawn challenging research for advanced engineering applications. Herein, considerable efforts have been devoted to enhancing the strength and wear resistance of face-centered cubic (FCC)-structured CoCrFeMnNi high entropy alloy (HEA) by incorporating HfO2 nanoparticles (NPs) through a powder metallurgy approach. The phase composition, microstructure, mechanical, and tribological properties of HEA composites were investigated. The XRD results reveal that the composite powders consisted of the FCC solid solution along with minor HfO2 phases. In addition, sintered HEAs showed the major FCC phase along with minor Cr-rich and HfO2 phases. Microscopic results confirmed the uniform distribution of HfO2 NPs throughout the matrix during the milling process. With increasing HfO2 contents, the hardness of the HEAs increased from 270 ± 10 to 520 ± 10 HV, while the compressive yield strength increased from 370 to 1500 MPa, due to dispersion and grain boundary strengthening effects. Furthermore, composite HEAs showed a decrease in coefficient of friction and wear rates with increasing HfO2 content due to increased surface hardness and transition in wear mechanism from severe wear to mild abrasive wear. The present study demonstrates the feasibility of producing high-performance oxide dispersion-strengthened HEAs for advanced structural applications.

High-pressure homogenization modified chickpea protein: Rheological properties, thermal properties and microstructure

Chickpea protein has the unique advantages of high yield and high bioavailability, and is used in the food industry. The existing research on the modification of chickpea protein has been focused on chemical modification. In this study, high-pressure homogenization (HPH) (physical) modification was attempted to explore the effects of HPH modification on the rheological properties, thermal properties and microstructure of chickpea protein dispersion (CPD). The results demonstrated that when CPD was modified by 90 MPa pressure, the apparent viscosity was increased from 185.69 to 521.16 Pa s, the frequency dependence was the highest, the recovery rate was raised from 42.80% to 54.27% and the protein solubility was the best (0.448%). The D [3,2] of CPD was decreased from 11.43 to 0.677 μm and the D [4,3] of CPD was reduced from 28.86 to 1.89 μm after HPH modification. The denaturation temperature of the protein was 110.56 °C at 150 MPa pressure. It was also found that with increasing pressure, the surface morphology of CPD was smoother and more regular after drying. The results demonstrated that the functional properties of chickpea protein were improved by HPH modification, which provided a potential strategy for the application of chickpea protein.

Terahertz Absorption Characteristics of Multiwalled Carbon Nanotube Aqueous Dispersion Measured by Microfluidic Technique

Multiwalled carbon nanotubes (MWCNTs) have excellent electronic, mechanical, and structural characteristics; however, their poor dispersion structure and large aggregates severely inhibit their function. A stable MWCNT dispersion in an aqueous solvent has been realized via ultrasonic dispersion and surfactant modification, providing a reference for improving MWCNT dispersion in various materials and solvents. In this study, a cyclic olefin copolymer with high transmittance to terahertz (THz) waves is used to prepare microfluidic chips. Then, the microfluidic and THz technologies are combined to study the THz absorption characteristics of MWCNT aqueous dispersion under different electric field (EF) intensities, magnetic field (MF) intensities, and MF action time. The results show that the THz spectral intensity of MWCNT aqueous dispersion decreases and the absorption coefficient increases with the increase of EF intensity, MF intensity, and MF action time. This phenomenon is explained from a microscopic perspective. The combination of microfluidic and THz technologies provides technical support for studying the characteristics of MWCNT aqueous dispersion and lays a foundation for elucidating the molecular microstructure of MWCNT aqueous dispersion.

Wear resistance, hardness, and microstructure of carbide dispersion strengthened high-entropy alloys

Wear resistance, hardness, and microstructure of carbide dispersion strengthened high-entropy alloys