Pressure Filtration Research Articles

Optimisation of punching parameters for enhanced filtration performance of non-woven by response surface methodology

This work highlights the relevance of punch density, needle penetration depth and basis weight on the nonwoven fabric’s properties. Fibre fineness-specific optimised carding parameters, that is feeder, cylinder and doffer speeds were used for the preparation of carded web to produce considered basis weight of carded batts. Fabric thickness, bursting strength, mean flow pore size, air permeability, air filtration efficiency and pressure drop were extensively investigated, and a relationship was developed using the Box–Behnken design. The punch density and needle penetration depth were optimised to achieve the required levels of mean flow pore size at constant basis weight for enhancing the air filtration behaviour of non-woven fabrics.

Investigation of in-situ lithium dendrite growth in the garnet type electrolyte Li7-xLa3Zr2-xTaxO12 (LLZTO) under an applied DC voltage

A translucent Al-containing garnet type electrolyte (Al-LLZTO) with high lithium-ion conductivity was made by pressure filtration followed by sintering to study in-situ lithium dendrite growth. A transparent tube furnace was built for in-situ dendrite growth studies above room temperature. In-situ lithium dendrite growth in a garnet-type electrolyte under an applied DC voltage was investigated at three different temperatures (room temperature, 100 °C, and 200 °C (above the melting point of lithium)). Critical current density (CCD) was estimated based on a previous model developed for sodium dendrites (which are actually filaments) in Na-β”-alumina. The CCD defined here is different than most of the reported work in lithium and lithium-ion batteries. When the temperature is higher than room temperature but lower than the melting point of lithium, lithium dendrites grow rapidly. However, when the temperature is above the melting point of lithium, no lithium dendrites were observed under similar testing conditions. This is because the CCD for liquid lithium dendrites to form is much higher than that for solid lithium dendrites to form. Approximate estimates of the CCD below and above the melting point of lithium are also given. This investigation provides significant insights into dendrite (filament) growth above room temperature, and possible prevention of lithium dendrites in working solid-state lithium-ion batteries, and the efficiency improvement of solid-state batteries.

Synergistic enhancement of coal slurry water sedimentation and dehydration process using PDMDAAC/PAM

Currently, most coal processing plants use a single pharmaceutical system with large dosage and poor sedimentation effect, resulting in poor subsequent dehydration effect. In this study, poly dimethyl diallyl ammonium chloride (PDMDAAC) as coagulant, and polyacrylamide (PAM) as flocculant, were used for synergistic enhancement of the coal slurry water sedimentation and dehydration process. The best pharmaceutical system was determined by integrating the evaluation indexes in the sedimentation and dehydration process. The mechanism of synergistic enhancement of coal slurry water sedimentation and dehydration process using PDMDAAC/PAM was revealed by analyzing zeta potential, SEM, XPS and FTIR spectroscopy results. Moreover, the Box–Behnken response surface methodology was used to determine the order of significance of coagulant dosage (Cc), flocculant dosage (Cm), and coal slurry water concentration (Cs) on the combined sedimentation and dehydration indexes, and Cm > Cs > Cc. Further, the correlation models between the combined sedimentation and dehydration indexes and each factor were established, the pharmaceutical system was further optimized, and model accuracy was verified. The optimal dosage of PDMDAAC10040 was 2.96 mg/L, and that of PAM2610 was 2.31 mg/L. Then, the industrial trials were conducted at the Tara Trench coal processing plant. Interestingly, after replacing the chemical regime, the efficiency of the thickener and filter press has been significantly improved, resulting in a 33.33% reduction in cost. This research can provide significant theoretical guidance and technical support for industrial applications.

Functionalized nano core-shell polystyrene spheres with polyionic liquids: An efficient shale stabilizer with both inhibit hydration and physical plugging

Due to shale hydration and the development of nano and micropores, wellbore instability often occurs during shale drilling, and high-performance shale stabilizers are urgently needed. A novel nano spherical shale stabilizer (i.e., PSIL) was prepared by polymerizing vinyl imidazole ionic liquid with amino group and polystyrene seed. The electron microscopy experiments and particle size analysis indicated that PSIL had a core-shell spherical structure with a particle size distribution between 200 and 300 nm. The plugging performance of PSIL was analyzed using the microporous membrane filtration experiment and pressure transfer experiment. The final filtration loss volume of 3 wt% PSIL aqueous solution was only 20 mL, and the final pressure at the end of the core was 4.0 MPa, which demonstrated that PSIL could form a dense plugging layer in the nanopore gap, thus reducing filtration loss and pressure transfer. Moreover, when the solution contained 3 wt% PSIL, the linear expansion rates of the bentonite pellets decreased from 69.1% to 38.3%, and the rolling recovery rate of shale cuttings increased from 10.5% to 41.2%. The experimental results indicated that PSIL could effectively be adsorbed onto the clay surface through electrostatic interaction and hydrogen bonds, thus reducing the repulsive force between clay interlayers and inhibiting the hydration dispersion of shales. Therefore, PSIL could play a dual role in physical plugging and inhibiting hydration, providing a new direction for developing high-performance shale inhibitors, thereby enhancing wellbore stability during drilling.

ВЗАИМОСВЯЗЬ НЕЛИНЕЙНЫХ МАТЕМАТИЧЕСКИХ МОДЕЛЕЙ ОБРАЗОВАНИЯ ГЛИНИСТОЙ КОРКИ В РАДИАЛЬНОЙ И ЛИНЕЙНОЙ ГЕОМЕТРИИ

A quasi-stationary model for the formation of a clay filter during well drilling in depth intervals with permeable rocks is proposed, on the basis of which the physical parameters of the media, reservoir and well are established, which determine the dependence of its radial dimensions on time. It is assumed that the filtration pressure fields are described by stationary piezoconductivity equations. The dependence of pressure, mudcake thickness, radius of the zone of pressure disturbances in the permeable rock during drilling and other parameters on time is parametric. Such a dependence arises from an additional equation that relates the amount of fluid absorbed by the formation and the filtration rate at the inlet to the porous medium. The general formulation of the problem, which includes the stationary piezoconductivity equations for the mudcake and reservoir, boundary conditions, and an additional equation, is non-linear, since the boundaries of the perturbation zone in the reservoir and the mudcake are mobile. An analytical solution of the problem was constructed, on the basis of which studies were carried out on the influence of the physical parameters of the medium, wells, etc. on the process of formation of a clay cake in real conditions. Integrals of motion of a nonlinear problem are found, which represent invariant complexes of parameters that do not change during the formation of a mud cake. The presence of such integrals made it possible to establish the relationship between the solutions of problems presented in radial and linear geometries. It is shown that in the particular case of a thin mud filter, the obtained expressions for the radial geometry coincide with the known ones, when the geometric factor of the drilling fluid filtrate corresponds to a flat flow. New possibilities for estimating the physical parameters of reservoirs based on caliper logging have been identified. The solution of this problem is especially important for horizontal wells, in which the intervals of clay cake have a significant length, and its formation occurs under conditions of a wide range of reservoir properties of the formation. The considered problem is of practical importance, since the zone of penetration of the drilling fluid filtrate into the formation has a screening effect on the use of geophysical methods to determine the saturation of the formations. The obtained solutions can be used both to improve the interpretation of geophysical methods and the development of drilling technology.

Preparation and in vitro degradation behavior of biodegradable porous Zn-Li-Ca alloy bone repair scaffolds

Porous pure Zn alloy scaffolds are often used for bone defects, but their clinical effects are limited due to poor mechanical properties and uneven degradation. In this study, porous Zn-Li-Ca alloy scaffolds with 70 % porosity were prepared by pressure infiltration method with 450–600 μm NaCl particles were used as pore-making agent. The effect of pore structure and the content of Ca element on, mechanical properties, degradation and weight loss of porous Zn alloy scaffolds soaked in simulated body fluids (SBF) for 4 weeks were studied. The results showed that the Zn alloy scaffolds prepared by spherical sodium chloride has high pore connectivity, and the yield strength and elastic modulus of Zn-0.8Li-0.8Ca reach 35.80 ± 1.89 MPa and 2.45 ± 0.19 GPa, respectively. Compared with the pure Zn alloy scaffolds, the yield strength was increased by 18.5 times, the elastic modulus was increased by 9 times, which meets the mechanical requirements of human cancellous bone. Compared with Zn-0.8Li alloy scaffolds, the weight loss rate and degradation rate at 4 weeks reached 7.51 % and 0.21 mm/y, respectively. In vitro studies showed that the addition of Ca element weakened the formation of Li2CO3 protective layer and accelerated the degradation rate of the scaffold. The problem of slow degradation rate of Zn-Li alloy was solved, which laid a foundation for subsequent in vivo implantation experiments. The results of this study indicate that the porous biodegradable Zn-based scaffold has great application potential in bone defects.

PRODUCTION TECHNOLOGY OF VEGETABLE PROTEIN-VITAMIN PASTE

The problem of providing the population of Ukraine with products of animal origin is currently very urgent, because barely two-thirds of the population is supplied with meat products, and a little more than half with dairy products. Traditional harvesting technologies cannot provide a sufficient amount of highly nutritious fodder, mainly due to significant losses during the implementation of technological operations. One of the ways to increase the intensity of fodder production is the fractional harvesting of high-protein green plants with the allocation of protein-vitamin concentrate as the main type of fodder. The analysis of the latest research and publications showed that currently there are no single, scientifically based recommendations regarding the rational set of machines and mode parameters of their operation when implementing this technology. Based on the results of previous studies, an experimental set of machines was formed to implement the technology of wet fractionation of alfalfa. The technological scheme includes such lines as dosing, disintegration (shredding) and wet fractionation of green plants, a line for coagulation of green juice, a line for separating the suspension obtained as a result of coagulation, a line for drying vegetable protein-vitamin concentrate and making pellets from it. Modeling the operation of the specified complex of machines allowed to determine the rational parameters of the operation of most of them, to outline the ways of further improvement of the nomenclature of machines, their location in technological lines, etc. For example, to increase the productivity of the filtration operation of the suspension obtained after coagulation of the green juice of alfalfa, it is advisable to direct it to special tanks for settling before sending it to the filter press, which will allow to increase the output of the protein-vitamin concentrate after filtering. The conducted modeling of the experimental complex of machines for the implementation of the fractional technology of harvesting alfalfa with the production of protein-vitamin concentrate showed the prospects of this technology for the development of the fodder industry.

Catheter-associated bladder mucosal trauma during intermittent voiding: An experimental study in pigs.

The objective of this study is to characterize bladder mucosal trauma associated with intermittent catheterization with conventional eyelet catheters (CECs) and to assess if a microhole zone catheter (MHZC) design concept reduces this adverse effect. A porcine model was developed to reflect human catheterization and bladder drainage. Nine pigs were randomized for catheterization with CEC (n= 6) or MHZC (n= 3). The bladder was drained repeatedly 20 times through the catheter. Cystoscopy was performed before and after the procedure, and bladders were analysed by histopathology. Two additional pigs were used for cystoscopy visualization of suction events in vivo. Cystoscopy, gross pathology, histopathological score, leucocyte infiltration, and intracatheter pressure at flow stops during voiding were compared for each group. A significant higher pressure gradient was measured inside the CECs compared with MHZCs during flow stop. Consequently, CECs resulted in suction events inflicting bladder trauma characterized by loss of epithelium, oedema, haemorrhage, and neutrophil tissue infiltration. No significant trauma was identified when using MHZC. Considerable mucosal bladder trauma is inflicted by CECs which may be an overlooked risk factor for urinary tract infection. Catheters can be designed to minimize mucosal suction and reduce associated trauma. This may be a solution to reduce infection frequency and increase user comfort. Furthermore, the study demonstrates the potential of pigs as an attractive animal model for investigating urinary catheter performances.

Experimental Study on Mechanical Properties of Marine Mud Slurry Treated by Flocculation-Solidification-High Pressure Filtration Combined Method

For the massive quantities and negative impacts of dredged mud slurry, its disposal and utilization have become one of the most noticeable issues in the world. In this paper, the flocculation-solidification-high pressure filtration combined method is proposed to effectively dispose of marine mud slurries. The advantages of this method are demonstrated herein in the following three aspects: dewatering performance, material savings, and the shear strength of the treated marine mud slurry. Then, the effects of the anionic polyacrylamide (APAM) dose, composite solidification agent dose, initial water content of marine mud slurries, and initial thickness of geo-bags on the mechanical properties of the marine mud slurry treated by the flocculation-solidification-high pressure filtration combined method are studied. Experimental results show that with increasing doses of APAM, the structures of mud slurries become more stable, and the optimal dose of APAM is determined as 0.16%. Moreover, the increase in the composite solidification agent dose and initial water content of the marine mud slurry, and the decrease in the initial thickness of geo-bags both contribute to the increase in the shear strength of the marine mud slurry treated by the flocculation-solidification-high pressure filtration combined method.

Fabrication and characterization of SiC/Al composites prepared by laser powder bed fusion (LPBF) combined with vacuum pressure infiltration

A novel method has been developed to fabricate SiC/Al composites by the combination of laser powder bed fusion (LPBF) and vacuum-pressure infiltration. The effects of the SiC particle size distribution and pre-oxidation on the microstructure and properties of SiC/Al composites were investigated. A new phenomenon of severe lamellar cracking was observed in SiC/Al composites without pre-oxidation treatment, which can be explained in terms of the mechanism of interlayer bonding. The results showed that the residual porosity of the sample without pre-oxidation treatment s was higher than 3 %, with a maximum of (8.16±0.57) %, which was much higher than that of the pre-oxidised samples(1 % – 2%). The bulk density of the powders was significantly improved by designing the material system with mono-, bi-, and tri-modal particle size distributions and the density of final SiC/Al samples gradually increases from 2.804±0.009 to 2.871±0.008 g/cm3, and the volume fraction of SiC increases from 36.7 vol% to 50.1 vol%. As a result, the coefficients of thermal expansion (CTE) of SiC/Al composites varies consistently with the volume fraction of SiC, decreasing from 13.72 to 10.84×10−6 °C−1. Our study shows that this method has the potential for great applications.

Numerical study on filtration characteristics of high-temperature particulate matter in a three-dimensional randomly arranged multi-granularity particle bed filter

The transformation of internal filter granules into a heterogeneous size distribution through abrasion alters filtration properties. This research constructs an abraded multi-granularity particle bed filter via unidirectional coupling of the discrete element method and computational fluid dynamics. The study examined the filtration characteristics of fine particulate matter at high temperatures. The findings indicate that the abraded multi-granularity beds were higher than the uniform size granular beds in both pressure drop and filtration efficiency. The abraded multi-granularity bed enhances filtration efficiency with a proportionally minor increase in pressure drop relative to the uniform size granular bed. In comparison to a stratified bed structure, the mixed configuration of the multi-granularity bed yields greater filtration efficiencies with less escalation in pressure drop. To maintain filtration efficiency beyond 90%, higher temperatures necessitate an augmented inlet flow rate, requiring an increase by a factor of 2.23 at 1000 K relative to 300 K.

Multi-objective impact mechanism on the performance characteristic for a diesel particulate filter by RF-NSGA III-TOPSIS during soot loading

Diesel particulate filter (DPF) provides an effective control method for particulate matter (PM) emissions from diesel vehicles. In the PM trap process of DPF, pressure drop and filtration efficiency present conflicting relationships as the main indicators of the comprehensive trap performance. To fully optimize the comprehensive trap performance of DPF, this research develops a hybrid multi-objective optimization approach of FGRA-RF-NSGA III-TOPSIS. Specifically, critical structures are selected from DPF structural features by fuzzy grey correlation analysis (FGRA). Three machine learning (ML) models are trained on the computational fluid dynamics (CFD) model dataset to relate the critical structures to the initial filtration efficiency and pressure drop. Then, statistical indicators are introduced to evaluate three ML models, and the best-performing model – The random forest (RF) model is selected as the input of the optimization algorithm. Finally, a hybrid Critic-TOPSIS approach is used to select the most ideal solution from the Pareto frontier obtained by the NSGA III as the output of the optimization results. The optimized DPF reduces the pressure drop by 49.84 % and improves the initial filtration efficiency by 49.31 % compared to the original DPF under standard operating conditions. The optimization effect is more significant at high-speed and high-load conditions.

Design and testing of a sew-free origami mask for improvised respiratory protection

Respiratory aerosols with diameters smaller than 100 μm have been confirmed as important vectors for the spread of diseases such as SARS-CoV-2. While disposable and cloth masks afford some protection, they are typically inefficient at filtering these aerosols and require specialized fabrication devices to produce. We describe a fabrication technique that makes use of a folding procedure (origami) to transform any filtration material into a mask. These origami masks can be fabricated by non-experts at minimal cost and effort, provide adequate filtration efficiencies, and are easily scaled to different facial sizes. Using a mannequin fit test simulator, we demonstrate that these masks can provide filtration efficiencies of over 90% while simultaneously providing greater comfort as demonstrated by pressure drops of <20 Pa. We also quantify mask leakage by measuring the variations in filtration efficiency and pressure drop when masks are sealed to the mannequin face compared to when the mask is unsealed but positioned to achieve the best fit. While leakage generally trended with pressure drop, some of the best performing mask media achieved <10% reduction in filtration efficiency due to leakage. Because this mask can provide high filtration efficiencies at low pressure drop compared to commercial alternatives, it is likely to promote greater mask wearing tolerance and acceptance.

Influence of Some Key Parameters on the Efficiency of Flocculation–Solidification–Filter Press Combined Method for Sustainable Treatment of Waste Mud Slurry

The flocculation–solidification–filter-press combined method is a new type of method for treating waste slurry that combines flocculation and chemical curing with a mechanical filter press. Among these processes, the mechanical filter-press process is key to the efficient disposal of waste engineering slurries by the flocculation–solidification–filter-press combined method. In the mechanical filter-press process, parameters including the initial thickness of filtration mud, the magnitude of filtration pressure, and the duration of press filtration have important impacts on the dewatering and strength after subsequent curing. In this work, a series of laboratory tests were conducted to study the influence of filter-press parameters on flocculated–solidified mud by measuring the properties of treated and cured mud. The test results showed that the initial mud bag thickness is an important factor in the mud treatment effect. As the initial mud bag thickness increases, the greater the water content of the mud at the end of the filter-press process after applying the same amount of time and the same amount of pressure, the lower the post-conservation strength will be. The increase in filtration pressure and filtration time within a certain range can reduce the water content of the mud brick after filtration and significantly improve its shear strength. In the actual process of filtering in the project, the thickness of the initial mud bag should be no more than 140 mm, the filtration pressure is about 0.35 MPa, and the filtration time is suitable for 2 min.

Pore characteristics of cake by filtration based on LBM-DEM-DLVO coupling method

Slurries containing fine particles are widely dewatered by flocculation combined with filtration. Understanding the microscopic filtration process of a flocculated slurry is helpful in designing flocculation and filtration schemes; however, there is currently limited research. In this study, the Lattice Boltzmann method–Discrete Element method–DLVO coupling method (LBM–DEM–DLVO) was used to conduct numerical experiments on the pore characteristics of cake by filtration. The numerical results demonstrate that the cake formed by filtration of the flocculated slurry contains two types of pores: interfloc and intrafloc pores. The diameter of the interfloc pores, which are the dominant channels for water seepage in the cake, is relatively large. The pore properties of the cake were significantly influenced by the interaction force between the particles in the floc and the filtration pressure; the mechanism was analyzed. Engineering proposals for dewatering are also presented. A multi-stage pressure treatment process and increased Finter during flocculation are recommended.

Manufacturing and characterization of an interpenetrating metal matrix composite reinforced with a 3D-printed metallic glass lattice structure (Ni60Nb20Ta20)

Metallic glasses (MG) exhibit remarkable properties, like high strength, hardness, and elastic strain limit due their amorphous structure. But they also exhibit low ductility and brittle behavior, making them less suitable for monolithic components. Therefore, MG offer high potential for use as a reinforcing phase in a ductile matrix. Especially interpenetrating metal matrix composites (MMCs) are suitable, since good interfacial adhesion can be achieved due to the metallic character of the MG and mechanical properties can be further enhanced by the interpenetrating structure. Temperature during manufacturing process must be below crystallization temperature of the MG. Until now, interpenetrating MMCs have been manufactured by infiltrating the metal matrix foam with MG, requiring a high melting temperature of the matrix and thus excludes lightweight metals. In this work it was possible to infiltrate an open porous lattice structure of MG (Ni60Nb20Ta20) due to its high crystallization temperature with AlSi12 by gas pressure infiltration resulting in a novel MMC. X-ray diffraction measurements confirm that no crystallization occurred during infiltration. Micrographs show a good infiltration quality and interfacial bonding between both phases. An increase in Young's modulus of 28 % and compressive strength in the MMC can be achieved compared to the AlSi12-matrix.

Cleaning performance improvement of a cone filter cartridge using a Venturi nozzle

To address the problem of the insufficient regeneration of dust filter cartridges, a Venturi nozzle is introduced to improve the cleaning performance. The jet distance, cone height, and compressed air pressure effects on the pulsed-jet pressure distribution were experimentally investigated. Changes in the filtration pressure drop, fallen dust mass, and dust emission were also studied. As the jet distance increased, the pulsed-jet pressure and the total pulsed-jet intensity first increased and then decreased for both cases of common and Venturi nozzles, but the pulsed-jet uniformity increased. In the Venturi nozzle case, the pulsed-jet pressure in the lower section of the cartridge was effectively increased due to the larger induced airflow. As the cone height increased, the pulsed-jet pressure in the lower section of the cartridge decreased and that in the upper section increased for both nozzle cases. The dust filtration-cleaning experiment showed that the Venturi nozzle improved the operation performance of the dust collector.

Significant enhancement in high temperature performance of TiAl matrix composites by a novel configuration design

Ti5Si3/TiAl composites were successfully prepared by pressure infiltration and subsequent reactive annealing. Final microstructure of Ti5Si3/TiAl composites was dependent on the reactive annealing temperature, which varied from 1350 °C to 1420 °C, two typical microstructures could be achieved: (i) An unique core-shell structure (Core: fully lamellar α2-Ti3Al/γ-TiAl with in-situ synthesized Ti5Si3 particles predominantly distributed at the interfaces of α2/γ lamellar colonies; Shell: equiaxed γ-TiAl with Ti5Si3 particles distributed in γ grain boundaries); And (ii) A novel quasi-network structure composed of fully lamellar α2/γ and a majority of Ti5Si3 particles with a quasi-network distribution. The formation of the two microstructures could be attributed to the chemical composition heterogeneity which was caused by the difference in interdiffusion rate of Ti and Al elements in different annealing temperatures. The comparative investigations on high temperature tensile properties and creep behavior showed that the core-shell Ti5Si3/TiAl composites exhibited a better specific strength (165 MPa⋅g−1⋅cm3) and higher ultimate tensile strength (633 MPa) at 800 °C, which was 12 % higher than that of the quasi-network Ti5Si3/TiAl composites. While the creep behavior analysis showed that in compassion with equiaxed γ phase, the slip distance of dislocations in fully lamellar α2/γ phase was shorter, impeding the motion of dislocations more effectively. And core-shell Ti5Si3/TiAl composites possessed a large number of grain boundaries concentrating in the shell which became weaker in the high temperature, facilitating the formation of creep pores in the shell and the final premature fracture. Hence, the quasi-network Ti5Si3/TiAl composites containing a higher content of fully lamellar α2/γ exhibited a better creep resistance than that of core-shell Ti5Si3/TiAl composites. More importantly, the steady state creep rate at 750 °C under the fixed stress of 250 MPa of quasi-network Ti5Si3/TiAl composites was relatively low, only 3.305 × 10−8 s−1, comparable to that of third-generation TiAl alloys.

Investigation of oil mist filtration performance of surface modified coalescence filters with asymmetric wettability

Fibrous coalescence filters are widely used to remove oil mists from air and gas streams in industrial applications. The wettability of filter media significantly affects the filtration performance. Although some efforts have been made to improve the filtration performance based on the modification of filter media wettability by surface treatment method, of which the influence on liquid transport mechanism in the filters and the filtration performance is still needed to elucidate. In this paper, oleophilic filter media were treated by fluorocarbon copolymer solution using a spraying method. The effects of the treated area ratio, spraying time and combinations of patterned filter media on the filtration performance were investigated experimentally. The results show that the increase of the treated area ratio contributes to a variation on the wettability from oleophilic to oleophobic, resulting in a decrease in the jump pressure drop and an increase in the filtration efficiency. The treated filter medium under the optimal spraying time has the highest quality factor, which is 2 ∼ 3 times the untreated one. For the dual-layer patterned filters with alternative oleophobic and oleophilic strips, when the number of oleophobic strips patterned in the first layer filter medium is the same, the pressure drop and filtration efficiency of the overlapped arrangement are lower than those of the staggered arrangement. In all configurations, the highest quality factor is found in the dual-layer filter with the overlapped arrangement and four oleophobic strips patterned in the first layer, resulting from the lowest steady pressure drop and relatively high filtration efficiency.

Highly conductive diamond skeleton reinforced Cu-matrix composites for high-efficiency thermal management

The weak interfacial bonding strength between diamond and copper intrinsically restricts the enhancement of the thermal conductivity of diamond particles/copper composites (abbreviated as DP/Cu). This work first proposed the diamond skeleton (DS) as the reinforcement element rather than dispersed diamond particles. The tungsten (W) transition layer (c.a. ∼300 nm thick) having adequate thermal expansion coefficient was sputtered onto the surface of DS via vacuum evaporation technology, aiming to improve the wettability between diamond and copper and accordingly increase the thermal conductivity of DS/copper composites extruded by gas pressure infiltration technique. The experimental results show that the coated W layer can effectively improve the wettability of the diamond surface and reduce the wettability angle from 108.6° to 13.2°. Raman and XRD spectra show that the W layer can, to a great extent, prevent the graphitization of the diamond surface. SEM and EDX evidence a continuous heat transfer path of DS inside the composites. The thermal conductivity of the DS/Cu composite with low diamond loading of 18.4 vol% reaches 575 W/mK, 43.3% higher than that of pure Cu. Finite element simulations show that DS exhibits excellent heat transfer characteristics, agreeing well with the thermal conductivity simulation results.