Matrix Composites Research Articles

Enhanced strength and ductility of boron nitride nanosheet reinforced cu composites through constructing an interfacial three-dimensional structure

To address the poor wettability and weak interface bonding between boron nitride nanosheet (BNNS) and Cu, BNNS/CuTi composites were prepared through matrix microalloying by adding 1 wt% Ti. Solid-state interfacial reactions resulted in the formation of TiN transition layers and TiB whiskers (TiBw), collectively constructed a BNNS-(TiN&TiB)-Cu interfacial three-dimensional structure (I-3DS). The coherent I-3DS significantly reduced the interfacial energy, improved the interfacial stability, and achieved a favorable combination of strength and ductility in BNNS/CuTi composites. The 0.1 wt% BNNS/CuTi composite achieved an ultimate tensile strength (UTS) of 485 MPa, representing increases of 114 % and 62 % over pure Cu and 0.1 wt% BNNS/Cu composite, respectively. The interlocking structure formed by I-3DS and Cu doubled the theoretical interface shear strength limit and improved load transfer efficiency. This study offered new insights into the innovative design of high-performance Cu matrix composites (CMCs) by constructing I-3DS.

Structure-property relationship of ultrasound-assisted nanoemulsion-impregnated bioactive polysaccharide films for enhanced shelf life of mushrooms

This study aimed to develop bioactive nanoemulsion (NE)-impregnated polysaccharide films to extend the shelf life of mushrooms. A stable and well-dispersed NE was prepared using 5 wt% soy protein (SP) and 10 % (v/v) lavender essential oil (LEO) through 10 min of ultrasound treatment, resulting in a droplet size of 152.3 nm, a polydispersity index (PDI) of 0.17, and a ζ-potential of −43.4 mV. Two types of films were prepared by incorporating 5 % and 10 % (v/v) SP/LEO NE into a curdlan (CD) and chitosan (CS) composite matrix, forming CD-CS-NE1 and CD-CS-NE2 films, respectively. The CD-CS-NE2 films possessed the highest tensile strength (14.5 MPa) and elongation at break (140 %). FTIR and molecular docking studies confirmed strong intermolecular interactions between the CD, CS, and NE components. The antibacterial activity of the NE-impregnated CD-CS films was significantly enhanced, with inhibition zones of 22 mm and 26 mm for Escherichia coli and Staphylococcus aureus, respectively, in the CD-CS-NE2 film. Growth curve and colony-forming unit (CFU) analyses further supported the superior antibacterial performance of the CD-CS-NE2 film. In mushroom storage tests, the CD-CS-NE2 film extended the shelf life of button mushrooms to 12 days and straw mushrooms to 4 days. Additionally, it reduced weight loss to 3 % and 4 % in button and straw mushrooms after 12 and 4 days, respectively. Mushrooms treated with CD-CS-NE2 film maintained higher firmness, with values of 18 N for button mushrooms and 6 N for straw mushrooms. The films effectively suppressed polyphenol oxidase (PPO) activity and browning. Overall, these findings suggest that SP/LEO NE-impregnated CD-CS films have strong potential for improving food preservation and reducing spoilage, particularly in fresh produce like mushrooms.

Graphene oxide, starch, and kraft lignin bio-nanocomposite controlled-release phosphorus fertilizer: Effect on P management and maize growth

This study focuses on the synthesis and practical application of bio-nanocomposite films made from a mixture of starch (ST) and Kraft lignin (KL) with graphene oxide (GO) nanoparticles. FTIR, XRD, Raman, SEM, and TEM analysis confirmed the synthesis's success of GO. The bio-nanocomposites were used as advanced coatings for triple superphosphate (TSP) fertilizers, and their implications for maize (Zea mays L.) plant growth were examined. Incorporating GO into the composite matrix is a significant accomplishment of this study, as demonstrated by the noticeable changes observed in the FTIR spectra, indicating consequent structural changes. Morphological analyses conducted by SEM reveal changes in the surface characteristics of the ST/KL films, providing essential information about the structural details of the bio-nanocomposite. The utilization of precision-coated TSP fertilizers leads to a significant enhancement in mechanical strength, as demonstrated by the improved crush resistance. Furthermore, these formulations guarantee a gradual release of phosphorus, showcasing their potential for efficient nutrient management in agricultural settings. The study examines the practical application of coated TSP fertilizers in agriculture and their positive effects on various growth parameters of Maize (Zea mays L.) plants. Using these fertilizers promotes sustainable and efficient agricultural practices, contributing to developing innovative agrochemical solutions.

The role and mechanism of vascular wall cell ion channels in vascular fibrosis remodeling.

Fibrosis is usually the final pathological state of many chronic inflammatory diseases and may lead to organ malfunction. Excessive deposition of extracellular matrix (ECM) molecules is a characteristic of most fibrotic tissues. The blood vessel wall contains three layers of membrane structure, including the intima, which is composed of endothelial cells; the media, which is composed of smooth muscle cells; and the adventitia, which is formed by the interaction of connective tissue and fibroblasts. The occurrence and progression of vascular remodeling are closely associated with cardiovascular diseases, and vascular remodeling can alter the original structure and function of the blood vessel. Dysregulation of the composition of the extracellular matrix in blood vessels leads to the continuous advancement of vascular stiffening and fibrosis. Vascular fibrosis reaction leads to excessive deposition of the extracellular matrix in the vascular adventitia, reduces vessel compliance, and ultimately alters key aspects of vascular biomechanics. The pathogenesis of fibrosis in the vasculature and strategies for its reversal have become interesting and important challenges. Ion channels are widely expressed in the cardiovascular system; they regulate blood pressure, maintain cardiovascular function homeostasis, and play important roles in ion transport, cell differentiation, proliferation. In blood vessels, different types of ion channels in fibroblasts, smooth muscle cells and endothelial cells may be relevant mediators of the development of fibrosis in organs or tissues. This review discusses the known roles of ion channels in vascular fibrosis remodeling and discusses potential therapeutic targets for regulating remodeling and repair after vascular injury.

Conjugate heat transfer performance of a ceramic matrix composite plate considering the influences of the mesoscopic properties of yarns

Ceramic matrix composites (CMCs), as a type of material with low density and excellent temperature resistance, are highly conducive to the lightweight and efficient development of future aerospace engines. It is essential to investigate the anisotropic thermal properties of CMCs when applying them to high-temperature components of aerospace engines. This study examined three types of film holes formed in different components of CMCs and compared the overall cooling effectiveness. The influence of the blowing ratio on the overall cooling effectiveness of composite material plates was investigated. The results showed that Type I exhibited better overall cooling effectiveness distribution than Types II and III. With the increase in blowing ratio, the overall cooling effectiveness of the plate was improved. The overall cooling effectiveness at M = 2.0 was 19.67 %, 16.72 %, and 12.1 % higher than those at M = 0.5, 1.0, and 1.5, respectively. The study also investigated the influence of the principal thermal conductivity and volume fraction of yarn on overall cooling effectiveness. An increase in the principal thermal conductivity resulted in an initial deterioration followed by improvement in the cooling effect in the upstream region, while increasing the yarn volume fraction enhanced the cooling effect of the plate.

Microstructure evolution and mechanical properties of selective laser melting fabricated hybrid particle reinforced AlSi10Mg composites

(SiC+TiB2)/AlSi10Mg composite powders with 5 wt% micro-SiC particles and 1.5 wt% nano-TiB2 particles were prepared by high energy ball milling, and hybrid particle reinforced aluminum matrix composites (AMCs) were fabricated by SLM. This study systematically investigated the effects of SiC and TiB2 particles on the phase composition, microstructure evolution, grain crystallization, and mechanical properties. The machanisms of potential strengthening and fracture mechanisms were revealed. The tribological behaviors of the hybrid particle reinforced AlSi10Mg composites under different friction conditions were explored as well. The results show that the 1.5 wt% nano-TiB2 particles provided sufficient nucleation sites for grain growth, completely transforming from coarse columnar to fined equiaxed grains. The average grain size decreases from 7.98 μm to 3.34 μm, and the texture is significantly weakened, which is beneficial to the homogenization of the microstructure, thereby improving the mechanical properties of the SiC/AlSi10Mg composites. The (SiC+TiB2)/AlSi10Mg composites showed a high ultimate tensile strength (~ 489.1 MP), hardness (172.2 HV) and elongation of 8.2 %. The enhancement of mechanical properties was attributed to Orowan strengthening, fine grain strengthening, and load-bearing strengthening. Due to the Si precipitates and fine microstructure, a low wear rate of 0.50 × 10−5 g/m was obtained, 10.7 % lower than that of SLM formed SiC/AlSi10Mg composites. The friction process is affected by abrasive wear, adhesive wear and delamination wear. It is aspired that the current approach can provide guidance for the design of new alloy systems with excellent performance.

Laser powder bed fusion of SiC particle-reinforced pre-alloyed TiB2/AlSi10Mg composite with high-strength and high-stiffness

Recently, laser powder bed fusion (LPBF) of particle-reinforced aluminum matrix composites (PAMCs) with high-strength and high-stiffness have attracted extensive attention in aviation and aerospace. However, performance improvement of single or dual PAMCs using traditional mechanical mixing method is still limited. Therefore, this study innovatively employed pre-alloyed ~6.5wt.% TiB2/AlSi10Mg composite as the matrix and mechanically mixed SiC particles with different contents (5 vol.% and 10 vol.%) to fabricate dual PAMCs with high particles content through LPBF. The results indicated that the 5 vol.% SiC+TiB2/AlSi10Mg composite revealed relatively weak agglomeration effect of SiC particle and highest relative density (~99.1%), thus exhibiting optimal processability. Using this composition material as the research object, it was found that the microstructure maintains the basic features of pre-alloyed TiB2/AlSi10Mg composite except for the slight grain coarsening. However, SiC particles react with α-Al matrix and Al3Ti. Then Al4C3 and TiC enhancement phase were formed, and micron-sized Si particles precipitated within the Al cells surrounded by the eutectic Al-Si. More importantly, due to novel preparation method of dual PAMCs powder, simultaneous enhancement in ultimate tensile strength (~554.0MPa), yield strength (~376.0MPa), and elastic modulus (~97.4GPa) was achieved. Total particle content (~14.0wt.%) and tensile property were higher than those of reported other PAMCs processed by LPBF. Finally, expect for the fracture characteristics inherent to the pre-alloyed TiB2/AlSi10Mg composite, new fracture mechanism for the tearing of SiC particles was exhibited. This work provides new insights into the preparation of high-strength and high-stiffness PAMCs processed by LPBF.

Effect of expandable graphite content on the physical, thermal and mechanical properties of novolac matrix composites: Halogen-free flame-retardant polymer composites

Flame-retardant properties are particularly important for materials used in high-temperature applications. This study focuses on novolac matrix composites reinforced with expandable graphite (EG) particles, produced through a hot pressing process using powders prepared by mechanical milling. The research examines the particle size of both the matrix and the reinforcing particles used in composite production. Additionally, the morphology of the powders, the microstructural properties of the composites, and the fracture surfaces after tensile testing were analyzed using scanning electron microscopy (SEM). Phase analysis of the samples was performed using X-ray diffraction (XRD). Hardness and tensile tests were conducted to evaluate the mechanical properties. The effect of EG particles on the thermal stability of the composites was assessed using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and thermal conductivity tests. Furthermore, flammability was evaluated by determining the Limit Oxygen Index (LOI) values. The experimental results identified the optimum reinforcement ratio as 20 wt% EG. TGA results showed residue values of approximately 37.39 % for pure novolac and 57.87 % for novolac matrix composites reinforced with 20 wt% EG. The highest thermal conductivity (0.72 W/mK) and LOI values (40.64 %) were achieved with 20 wt% EG reinforcement, resulting in an LOI value approximately 1.25 times greater than that of the pure novolac sample (32.45 %). Additionally, tensile strength increased by approximately 2.7 times compared to the pure novolac sample. This research highlights the potential of the novolac/EG composites for advanced high-temperature applications where enhanced flame retardancy and structural integrity are essential.

Synergistic Enhancement of 7075 Aluminum Alloy Composites via High Entropy Alloy Particle Integration: Microstructural and Mechanical Insights

This study investigates the impact of high-entropy alloy (HEA) particle reinforcement on the microstructure, mechanical properties, and performance of 7075 aluminum matrix composites (AMCs). Utilizing spark plasma sintering (SPS), composites with varying HEA particle concentrations were synthesized to assess their effects comprehensively. The results indicate that increasing HEA content significantly enhances the density and hardness of the composites. Specifically, a 20 wt% HEA reinforcement achieved a high hardness of 61 HRB and a density of 3.21 g/cm³. The compressive strength initially increased with HEA content but then decreased as it ranged from 5 wt% to 20 wt%. Optimal mechanical properties, including a compressive strength of 680 MPa and a fracture elongation of 33%, were observed at 10 wt% HEA. Wear testing further demonstrated the advantages of HEA reinforcement, with a substantial reduction in wear rate from 9.97±1.1×10⁻⁴ to 2.06±0.1×10⁻⁴ mm³/N·m at 10 wt% HEA. Additional analyses using energy-dispersive X-ray spectroscopy (EDX) and nanoindentation identified an aluminum-rich transition layer at the HEA-aluminum interface, formed due to aluminum diffusion. This transition layer likely enhances interfacial wettability and bonding, contributing to the improved performance of the composite.

Machining of Cf/SiC composite with indigenously developed nano green cutting fluid: Machined surface fibre morphology

The Carbon fibre reinforced Silicon Carbide (Cf/Sic) composites are widely used in different industries such as automotive, aerospace, etc. The Cf/SiC is indigenous developed and detail of the fabrication procedure is presented. The nano fluid, namely Graphene Oxide Organo Boron (GOOB) is developed indigenously for using as the cutting fluid. This nano fluid is mixed in green cutting fluid (GCF) in different proportions and the concentration is optimized. The nano fluid is characterized by advanced techniques for the confirmation. To reduce the surface roughness on the fabricated Cf/SiC, end milling operation is carried out with different machining environments such as dry, flood cooling with cutting fluid and nano fluid and minimum quantity cutting fluid with nano fluid. The machining operations are carried out by varying different input parameters, namely, cutting speed, feed rate, and depth of cut. The results indicated that the minimum surface roughness of 1.845 μm is obtained when 0.5 % GOOB with GCF is used. This work would benefit the researchers exploring the preparation and interaction mechanism of the indigenously developed nano green cutting fluid for machining Cf/SiC-based ceramic matrix composites.

The Microstructure and Wear Properties of Ni-coated and Agglomerated-Sintered WC-10Ni/316 Composite by Laser Melting Deposition

WC-10Ni particle-reinforced stainless steel matrix composites have potential applications in aerospace, energy engineering, automotive manufacturing, and marine engineering equipment. However, there is currently insufficient research on the integrated manufacturing and comparative analysis of Ni-coated (WC-10Ni)1.5/316 and agglomerated-sintered (WC-10Ni)1.5/316 composites using Laser Melting Deposition (LMD) technology. In this work, the fabrication and examination of the LMDed specimens are conducted to determine the influence of the forming process of particle reinforcement on the microstructure and wear properties of WC-10Ni/316 composites. The microstructure, phase composition, composition distribution, microhardness, and wear resistance of the two composites were comparatively analyzed using confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), microhardness tester, X-ray diffraction(XRD), energy-dispersive spectroscopy (EDS), and a reciprocating wear tester. The results indicate that the microstructure of Ni-coated (WC-10Ni)1.5/316 composite specimen contains a higher quantity of undecomposed Ni-coated WC-10Ni particles, with a lower proportion of precipitates, and dendrites predominantly exhibit an elongated dendrite morphology. In contrast, the agglomerated-sintered (WC-10Ni)1.5/316 composite specimen features a greater content of decomposed agglomerated-sintered WC-10Ni particles, a higher content of precipitates, and dendrites mainly present as slender dendrites. Both composites consist of phases such as γ-(Fe, Ni, Cr), WC, W2C, Fe6W6C, M6C, and Cr23C6. The undecomposed WC-10Ni particles and tungsten precipitates significantly enhance the microhardness and wear resistance of the specimen. Specifically, the Ni-coated (WC-10Ni)1.5/316 composite specimen displays a microhardness of 350.2±3.3 HV1.0, with a wear rate of 1.5797±0.0455mg/(N·km). Meanwhile, the Agglomerated-sintered (WC-10Ni)1.5/316 composite specimen reveals an average microhardness of 410.9±6.1 HV1.0 and a wear rate of 0.8057±0.0352mg/(N·km).

Multiscale numerical scheme on shear failure feature of 3DOWC/Cs bar incorporating microlevel uncertainties and coupled constitutive behavior

In contrast to prevalently utilized carbon fiber reinforced plastics (CFRP), the carbon fiber reinforced carbon matrix composites (C/Cs) frequently present significantly divergent mechanics features. The current investigation dedicates to a robust multiscale finite element strategy on shear failure characteristics of three-dimensional orthogonal woven C/Cs (3DOWC/Cs) bolt bar together with relevant experimental measurement for validation, while the off-axial orientation sensibility of structural load-bearing performance and damage mechanism are systematically evaluated. In view of the complicated internal fabric architecture, the predictions are received via hierarchical numerical simulation at micro-, meso-, as well as macroscales. The random distributions of voids and fibers are incorporated to precisely capture the material properties, meanwhile the constitutive laws which embed the combining of Hashin and Puck criterions judging for yarn initial damage, multilinear rule for carbon matrix, and trilinear cohesive zone model (CZM) for interface, are implemented to render the coupling impacts of material behaviors. Besides, the extracted global load-displacement curves and local progressive failure morphologies from macroscale simulation are separately compared with experimental acquisitions to verify the accuracy of proposed modelling and to expose the damage mechanism of specimens with various off-axis angles. The contribution of this research lies in accurate quantification for microlevel uncertainties via modified stochastic algorithms, and applicable constitutive frame severally matching each material component to portray the distinctive mechanical particularities of 3DOWC/Cs.i

Abstract C045: The extracellular matrix glycoprotein periostin supports chemotherapy resistance by modulating macrophage recruitment and phagocytosis in triple negative breast cancer

Abstract Triple-negative breast cancer (TNBC) accounts for approximately 15–20% of all breast cancer cases and is notoriously aggressive, often developing resistance to standard chemotherapy thus leading to a high rate of metastatic relapse. Evidence suggests that this resistance is linked to changes in the extracellular matrix (ECM) composition, particularly an increase in periostin (POSTN) expression, which is also associated with poor prognosis in breast cancer. Our recent publication showed that the ECM alone can influence macrophage phenotypes. Furthermore, another study from our lab has demonstrated that POSTN mediates resistance to anti-angiogenic therapy by recruiting macrophages in pancreatic neuroendocrine tumors. Notably, POSTN deletion reduced monocyte/macrophage recruitment and enhanced cytotoxic CD8+ T-cell infiltration. Based on these findings, we hypothesized that paclitaxel (PTX), a widely used chemotherapeutic drug for the management of TNBC, may stimulate POSTN production by fibroblasts leading to the recruitment of pro-tumoral macrophages that facilitate tumor growth resulting into therapy resistance. In this study, we showed that PTX induces increased POSTN expression in mouse models of TNBC through immunohistochemistry, and in both 2D and 3D in vitro models via interactions between TNBC cell lines and mammary fibroblasts, as demonstrated by immunofluorescence. An in vitro migration assay confirmed that PTX-induced POSTN enhances the recruitment of human monocytes and macrophages, which display a mixed immunosuppressive and inflammatory phenotype, as revealed by flow cytometry. Not only did these recruited macrophages exhibit a reduced phagocytic capacity against labelled TNBC cells in an in vitro phagocytosis assay, but we also found that POSTN plays a crucial role in inducing SIRPα expression, that may diminish macrophage phagocytic potential. Increased sialylation and Siglec-1 expression are known to be linked to poor prognosis and polarization towards a more immunosuppressive macrophage phenotype in TNBC. Interestingly in our model, we observed that higher concentrations of recombinant human POSTN induce increased Siglec-1 expression on macrophages, a receptor that interacts with sialic acids in the tumor ECM. Further work using a decellularized tissue model that preserves only the ECM from patient-derived tumor biopsies pre- and post-chemo, aims to further explore the correlation between PTX-induced POSTN, ECM sialylation, and Siglec-1 expression on macrophages. Additionally, we have developed POSTN-knockout murine cancer cells and fibroblasts using CRISPR/Cas9, allowing us to investigate how POSTN influences macrophage phenotypes and chemotherapy responses in vivo. Understanding the mechanisms behind chemotherapy resistance in TNBC is crucial for developing effective treatments for this aggressive cancer subtype. By elucidating the intricate interplay between POSTN, macrophages, and chemotherapy response, we aim to identify new therapeutic strategies to improve outcomes for TNBC patients. Citation Format: Ludovica Tarantola, Ioanna Keklikoglou, Oliver M. Pearce. The extracellular matrix glycoprotein periostin supports chemotherapy resistance by modulating macrophage recruitment and phagocytosis in triple negative breast cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C045.

Elevating alloy performance: the role of bioactive glass in Mg-9Al-Zn matrix composites through friction stir back extrusion

ABSTRACT This study investigates the impact of friction stir back extrusion (FSBE) parameters on the microstructure and mechanical properties of magnesium matrix composites reinforced with bioactive glass particles. Higher rotational speeds (1600 rpm) generate more heat and stirring, promoting finer grains and better particle dispersion, while lower speeds lead to larger grains. Conversely, slower extrusion speeds allow more time for heat dissipation and better mixing, contributing to smaller grains and a more uniform particle distribution. Key findings show that increasing the bioactive glass content enhances both hardness and ultimate tensile strength (UTS), with optimal mechanical properties achieved at 1600 rpm rotational speed, 48.97 mm/min extrusion speed, and 5 vol.% bioactive glass. The introduction of bioactive glass particles restricts grain growth and improves load transfer, thereby reinforcing the composite. Additionally, the study identifies a gradient microstructure in the composite wire, with smaller grains near the surface due to higher plastic strain and temperature, in contrast to the core, which exhibits larger grains.

Graphene-reinforced metal matrix composites produced by high-pressure torsion: a review

Graphene-reinforced metal matrix composites produced by high-pressure torsion: a review

Enhancing predictive modeling of nano metal matrix composites with LEO-HDNN approach

Enhancing predictive modeling of nano metal matrix composites with LEO-HDNN approach

Effect of Alkalization Time on the Toughness and Strength of Jute Sack Waste Lamina Composite as an Alternative Car Bumper Material

Alkaline conditions, such as the concentration of Sodium Hydroxide (NaOH) and the duration of soaking time, significantly affect the mechanical properties of natural fiber and its composites. The objective of this study is to investigate the effect of alkali treatment on the impact toughness and tensile strength of laminated composites made from jute sack (burlap) waste woven fibers, which can potentially be used as a substitute material for vehicle bumpers. The experimental group comprised specimens that were alkalized by manipulating the duration of soaking and the concentration of alkali in the woven fibers of jute sack waste, with a fiber orientation pattern of 0°/+90°/0°/+90°/0°. The fiber immersion time is 24 hours, 48 hours, and 72 hours when using a 5% NaOH concentration. Epoxy resin serves as a composite matrix, specifically epoxy resin and epoxy hardener. Two sets of specimens underwent tests to measure their tensile and impact strengths. The result of the study reveals that the jute sack laminated epoxy composite with a fiber orientation of 0°/+90°/0°/+90°/0° had the maximum tensile strength and impact strength after a 48-hour alkaline treatment at 14.99 MPa and 0.010 J/mm2, respectively. The alkali treatment has successfully enhanced the tensile strength of the jute fiber by approximately 42.49% and 39.66% when compared to the untreated jute fiber. The study concludes that the utilization of alkaline process with NaOH improves the surface area of the fiber, compatibility with polymer matrix and mechanical strength.

Processing characteristics of C/C composites with nanosecond pulse laser

This study investigates the effects of the nanosecond pulse laser parameters on the processing characteristics of carbon fiber-reinforced carbon matrix (C/C) composites through a series of laser cutting experiments. It compares the cutting width, depth, heat-affected zone (HAZ) width, processed surface micro-morphology, as well as the oxidation characteristics of the material under different processing parameters. The HAZ width is analyzed in relation to the variations in the oxygen content. The results indicate that both the cutting width and depth initially increase and then decrease with increasing repetition frequency. Moreover, increasing the laser power and pulse width gradually increases the cutting width, depth, and HAZ width, whereas a higher scanning speed tends to reduce the cutting width and depth. Since changes in the processing power, scanning speed, and pulse width affect the HAZ, the oxygen content exhibits a proportional relationship with the HAZ width. In addition, an increase in the repetition frequency can expand the HAZ while reducing the oxygen content. A careful increase in the repetition frequency aids in lowering the ablation threshold of the material, leading to more material removal. Nevertheless, a continuous increase in energy density can trigger a fiber pull-out phenomenon and cause degradation of the matrix.

Machine learning potential for the Cu-W system

Combining the excellent thermal and electrical properties of Cu with the high abrasion resistance and thermal stability of W, Cu-W nanoparticle-reinforced metal matrix composites and nano-multilayers are finding applications as brazing fillers and shielding material for plasma and radiation. Due to the large lattice mismatch between fcc Cu and bcc W, these systems have complex interfaces that are beyond the scales suitable for methods, thus motivating the development of chemically accurate interatomic potentials. Here, a neural network potential (NNP) for Cu-W is developed within the Behler-Parrinello framework using a curated training dataset that captures metallurgically relevant local atomic environments. The Cu-W NNP accurately predicts (i) the metallurgical properties (elasticity, stacking faults, dislocations, thermodynamic behavior) in elemental Cu and W, (ii) energies and structures of Cu-W intermetallics and solid solutions, and (iii) a range of fcc Cu/bcc W interfaces, and exhibits physically reasonable behavior for solid W/liquid Cu systems. As will be demonstrated in forthcoming work, this near accurate NNP can be applied to understand complex phenomena involving interface-driven processes and properties in Cu-W composites. Published by the American Physical Society 2024

The High-Strain-Rate Impacts Behaviors of Bilayer TC4-(GNPs/TC4) Composites with a Hierarchical Microstructure

Ti matrix composites (TMCs) are promising structural materials that meet the increasing demands for light weight the automobile and aircraft industries. However, the room temperature brittleness in the traditionally homogeneous reinforcement distribution of TMCs limits their application in high-strain-rate impact environments. In the present study, novel bilayer TMCs with hierarchical microstructures were designed by the laminated combination of graphene nanoplatelet (GNPs) reinforced TC4 (Ti-6Al-4V) composites (GNPs/TC4) and a monolithic TC4. Meanwhile, the configuration of the microstructure, impact performance V50, and deformation modes of the bilayered TC4-(GNPs/TC4) plate was investigated. The plates were fabricated via field-assisted sintering technology (FAST). It turned out that the TC4-(GNPs/TC4) plate with a 7.5 mm thickness against a 7.62 mm projectile exhibited greater impact performance (V50~825 m/s) compared to the TC4 and GNPs/TC4 single-layer plates. The plate failure modes were dependent on the microstructure while the failure behaviors seemed to be influenced by the hierarchical configuration. This work provided a new strategy for utilizing TMCs in the field of high-strain-rate impact environments.