Damping properties and mechanism of aluminum matrix composites reinforced with glass cenospheres

The damping properties were improved by preparing Al matrix composites reinforced with glass cenospheres through the pressure infiltration method.Transmission electron microscopy and scanning electron microscopy were employed to characterize the microstructure of the composites.The low-frequency damping properties were examined by using a dynamic mechanical thermal analyzer,aiming at exploring the changing trend of damping capacity with strain,temperature,and frequency.The findings demonstrated that the damping value rose as temperature and strain increased,with a maximum value of 0.15.Additionally,the damping value decreased when the frequency increased.Dislocation damping under strain and interfacial damping under temperature served as the two primary damping mechanisms.The increase in the density of dislocation strong pinning points following heat treatment reduced the damping value,which was attributed to the heat treatment enhancement of the interfacial bonding force of the composites.

Study of the Diffusion Behavior of Seawater Absorption in Multi-Walled Carbon Nanotubes/Halloysite Nanotubes Hybrid Nanofillers Modified Epoxy-Based Glass/Carbon Fiber Composites

In the maritime industry, cost-effective and lightweight Fiber Reinforced Polymer (FRP) composites offer excellent mechanical properties, design flexibility, and corrosion resistance. However, their reliability in harsh seawater conditions is a concern. Researchers address this by exploring three approaches: coating fiber surfaces, hybridizing fibers and matrices with or without nanofillers, and interply rearrangement. This study focuses on evaluating the synergistic effects of interply rearrangement of glass/carbon fibers and hybrid nanofillers, specifically Multi-walled carbon nanotubes (MWCNT) and Halloysite nanotubes (HNT). The aim is to enhance impact properties by minimizing moisture absorption. Hybrid nanocomposites with equal-weight proportions of two nanofillers: 0 wt.%, 1 wt.%, and 2 wt.% were exposed to seawater for 90 days. Experimental data was subjected to modelling through the application of Predictive Fick’s Law. The study found that the hybrid composite containing 2 wt.% hybrid nanofillers exhibited a 22.10% increase in impact performance compared to non-modified counterparts. After 90 days of seawater aging, the material exhibited enhanced resistance to moisture absorption (15.74%) and minimal reduction in impact strength (8.52%) compared to its dry strength, with lower diffusion coefficients.

Microstructure evolution and nitrides precipitation in in-situ Ti_2 AlN/TiAl composites during isothermal aging at 900°C

Microstructures of Ti2AlN/TiAl composites prepared by in-situ method were characterized in in-situ and aging treatment conditions and the nitride precipitation was investigated in Ti2AlN/TiAl composites aged at 900 ℃ for 24 h after being heat treated at 1400 ℃ for 0.5 h. The in-situ composites consist of γ＋α2 lamellar colonies, equiaxed y grains and Ti2AlN reinforcements. Matrix with nearly fully lamellar structure formed after solution and subsequently aging treatment. With the increase of Ti2AlN content, the nearly fully lamellar structure becomes instable for the aged composites. According to TEM study, fine Ti2AlN precipitates are found to distribute at the grain boundaries of lamellar colony. Needle-like Ti3AlN precipitates arrange in line with growing axis parallel to [001] direction of the γ-TiAl matrix and another needle-like Ti3AlN precipitates with lager size distribute at the dislocations. Key words：

Effect of Nb on the corrosion behavior of continuous bulk metallic glass-coated steel wire composites

（Zr41.2Ti13.sCu12.sNi10Be22.5）100-~Nb~ （at%, x=0 and 8） bulk metallic glasses （BMGs） were coated on the surface of Q195 steel wires by a continuous coating process. The potentiodynamic polarization tests of these BMGs were conducted in 3.5wt% NaC1 aqueous solution. It is found that the addition of 8at% Nb into Zr41.2Ti13.sCu12.sNi10Be22.5 alloy results in the improvement of corrosion resistance with the pitting potential of -52 mV, the open circuit potential of-446 mV, and the corrosion current density of 9.86x 10-6 mA/cm2. This may be attributed to that Nb is beneficial to passivate and stabilize Zr and Ti.

Experimental and simulation studies on delamination strength of laminated glass composites having polyvinyl butyral and ethyl vinyl acetate inter-layers of different critical thicknesses

The laminated glasses(LGs)composites are gaining popularity as protectivestructural material. Delamination strength(DS) of(LGs) with different inter-layers and their different nominal thicknesses were compared. The effect of inter-layer thickness, delamination load, and inter-layer type on DS is clearly observed from this brief study. It is concluded that inter-layer thickness has the significant role in determining the DS of LGs. The statistical analysis confirmed the strong association of DS with inter-layer thickness and the interlayer type. It was found that the LG-PVB composite has the comparatively lower DS than LG-EVA composite and inter-layer thickness has the prominent role in the determination of DS in the LG-EVAcomposite. There is an increment in DS with an increment in critical inter-layer thickness in both LG-EVA and LG-PVBcomposites. The increment in the inter-layer thickness from 0.38 mm to 0.76 mm increases DS significantly; whereas, the further increment in the inter-layer thickness to the higher value has a lesser effect. The finite element model was constituted(without considering the effect of temperature) for determining DS of LG composite. The simulation results were in a good match with experimental results. The results of the present work can be utilized by the design engineers while selecting LG for structural applications.

Synthesis,structure and mechanical properties of Zr-Cu-based bulk metallic glass composites

The unusual glass-forming ability（GFA） of the Zr48Cu36Ag8Al8 alloy and the high ductility of the Zr48Cu36Ag8Al8 metallic glass-matrix composites containing Ta powder were reported.The bulk metallic glass rod with a diameter of 25 mm was successfully synthesized using copper mold casting for the Zr48Cu36Ag8Al8 alloy.High GFA of this alloy was found to be related to a large supercooled liquid region and a quaternary eutectic point with low melting temperature.The bulk metallic glass matrix composites were prepared by introducing extra Ta particles into the Zr48Cu36Ag8Al8 melt.The composites consist of Ta particles homogenously distributed in the Zr48Cu36Ag8Al8 metallic glass matrix.The optimum content of Ta powder is 10at%for the composite with the highest plasticity,which shows a plastic strain of 31%.

Thermal properties of pressureless melt infiltrated AlN-Si-Al composites

Thermal properties of AlN-Si-Al composites produced by pressureless melt infiltration of Al/Al alloys into porous a-Si3N4 preforms were investigated in a temperature range of 50-300 °C. SEM and TEM investigations revealed that the grain size of AlN particles was less than 1 μm. In spite of sub-micron grain size, composites showed relatively high thermal conductivity （TC）, 55-107 W/（m·K）. The thermal expansion coefficient （CTE） of the composite produced with commercial Al source, which has the highest TC of 107 W/（m·K）, was 6.5×10-6 K-1. Despite the high CTE of Al （23.6×10-6 K-1）, composites revealed significantly low CTE through the formation of Si and AlN phases during the infiltration process.

Ballistic impact properties of woven bamboo-woven E-glass-unsaturated polyester hybrid composites

In this study, a laminated woven bamboo/woven E glass/unsaturated polyester composite is developed to combat a ballistic impact from bullet under shooting test. The aim of this study is to understand the fundamental effects of the woven bamboo arrangement towards increasing ballistic resistance properties. The work focusses on the ballistic limit test known as NIJ V50, which qualifies materials to be registered for use in combat armor panels. The results show that the composites withstood 482.5 m/s ± 5 limit of bullet velocity, satisfying the NIJ test at level II. The findings give a strong sound basis decision to engineers whether or not green composites are qualified to replace synthetic composites in certain engineering applications.

Fabrication and performance of 3D co-continuous magnesium composites reinforced with Ti_(2)AlN_(x) MAX phase

Magnesium composites reinforced by N-deficient Ti_(2)AlN MAX phase were first fabricated by non-pressure infiltration of Mg into three-dimensional(3D)co-continuous porous Ti_(2)AlN_(x)(x=0.9,1.0)preforms.The relationship between their mechanical properties and micro-structure is discussed with the assessment of 2D and 3D characterization.X-ray diffraction(XRD)and scanning electron microscopy detected no impurities.The 3D reconstruction shows that the uniformly distributed pores in Ti_(2)AlN_(x) preforms are interconnected,which act as infiltra-tion tunnels for the melt Mg.The compressive yield strength and microhardness of Ti_(2)AlN_(0.9)/Mg are 353 MPa and 1.12 GPa,respectively,which are 8.55%and 6.67%lower than those of Ti_(2)AlN/Mg,respectively.The typical delamination and kink band occurred in Ti_(2)AlN_(x) under compressive and Vickers hardness(V_(H))tests.Owing to the continuous skeleton structure and strong interfacial bonding strength,the crack ini-tiated in Ti_(2)AlN_(x) was blocked by the plastic Mg matrix.This suggests the possibility of regulating the mechanical performance of Ti_(2)AlN/Mg composites by controlling the N vacancy and the hierarchical structure of Ti_(2)AlN skeleton.

High-cycle Fatigue Life Extension of Glass Fiber/Polymer Composites with Carbon Nanotubes

The present work shows that the addition of small volume fractions of multi-walled carbon nanotubes （CNTs） to the matrix results in a significant increase in the high-cycle fatigue life. It is proposed that carbon nanotubes tend to inhibit the formation of large cracks by nucleating nano-scale damage zones. In addition, the contribution to energy absorption from the fracture of nanotubes bridging across nano-scale cracks and from nanotube pull-out from the matrix are mechanisms that can improve the fatigue life. An energy-based model was proposed to estimate the additional strain energy absorbed in fatigue. The distributed nanotubes in the matrix appear to both distribute damage as well as inhibit damage propagation resulting in an overall improvement in the fatigue strength of glass fiber composites.

Preparation of Cu-based Bulk Metallic Glass Matrix Composites

Cu47Ti34Zr11Ni8 bulk metallic glass （BMG） matrix composites containing in situ formed TiC particles and 5-TiCu dendrite phase were developed by copper mold cast. The thermal stability and microstructure of the composites are investigated. Room temperature compression tests reveal that the composite samples exhibit higher fracture strength and distinct plastic strain of 0.2%-0.5%, comparing with that of the corresponding Cu47Ti34Zr11Ni8 monolithic BMG.

Application of semisolid process to Zr-based metallic glass matrix composites

The effect of the cooling slope on the structure of Zr-based metallic glass matrix composites was investigated by changing the cooling slope.The synthesis of bulk metallic glass composites was made by a process combining cooling slope casting and Cu mold casting for Zr66.4Nb6.4Cu10.5Ni8.7Al8 alloys.The results show that the semisolid slurry which consists of the spheroidal or rosette-type BCC crystals and the liquid phase which forms metallic glass phase can be formed by the cooling slope process in this alloy system.However,the semisolid slurry cannot reach to the mold.It is considered that higher viscosity of the liquid phase which forms metallic glass phase causes this result.Thus,parameters of the cooling slope have to be examined further.

Plasticity improvement of(Cu_(43)Zr_(48)Al_(9))_(98)Y_(2)bulk metallic glass composites by dispersed Ta particles

(Cu_(43)Zr_(48)Al_(9))_(98)Y_(2)-based bulk metallic glass composites(BMGCs)with dispersed Ta particles(3vol.%,6vol.%,9vol.%)were successfully fabricated through suction casting.The thermal properties,microstructure,and mechanical properties of the BMGCs were systematically investigated.Ta particles are homogeneously dispersed in the amorphous matrix.Ta particle reinforced BMGCs exhibit similar thermal properties and glass-forming ability with the Cu_(43)Zr_(48)Al_(9))_(98)Y_(2)base BMG.Compression test results show that the BMGC with 9vol.%Ta particles has superior mechanical performance with up to 15.7%compressive plastic strain,2,216 MPa yield strength,and 2,260 MPa fracture strength at room temperature.These homogeneously distributed Ta particles act as discrete obstacles in the amorphous matrix,restricting the highly localized shear band.This results in the formation of multiple shear bands around the Ta-rich particles,which lowers the stress concentration,allowing the shear band to propagate further and improve plasticity.

Effects of infiltration parameters on mechanical and microstructural properties of tungsten wire reinforced Cu_(47)Ti_(33)Zr_(11)Ni_6Sn_2Si_1 metallic glass matrix composites

Cu47Ti33Zr11Ni6Sn2Si1-based bulk metallic glass matrix composites reinforced with tungsten wires were fabricated by infiltration process at different temperatures （850, 900, 950 and 1000 °C） and time （10, 20 and 30 min） in a quartz or a steel tube. The mechanical tests were carried out by scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The results show that the maximum strength and total strain of the composite are 1778 MPa and 2.8% fabricated in steel tube at 900 °C for 10 min, and 1582 MPa and 3.6% fabricated in quartz tube at 850 °C for 10 min, respectively.

Composition Analysis and Identification of Ancient Glass Products Based on L1 Regularization Logistic Regression

In view of the composition analysis and identification of ancient glass products, L1 regularization, K-Means cluster analysis, elbow rule and other methods were comprehensively used to build logical regression, cluster analysis, hyper-parameter test and other models, and SPSS, Python and other tools were used to obtain the classification rules of glass products under different fluxes, sub classification under different chemical compositions, hyper-parameter K value test and rationality analysis. Research can provide theoretical support for the protection and restoration of ancient glass relics.

Research on properties of hollow glass microspheres/epoxy resin composites applied in deep rock in-situ temperature-preserved coring

Deep petroleum resources are in a high-temperature environment.However,the traditional deep rock coring method has no temperature preserved measures and ignores the effect of temperature on rock porosity and permeability,which will lead to the distortion of the petroleum resources reserves assessment.Therefore,the hollow glass microspheres/epoxy resin(HGM/EP)composites were innovatively proposed as temperature preserved materials for in-situ temperature-preserved coring(ITP-Coring),and the physical,mechanical,and temperature preserved properties were evaluated.The results indicated that:As the HGM content increased,the density and mechanical properties of the composites gradually decreased,while the water absorption was deficient without hydrostatic pressure.For composites with 50 vol%HGM,when the hydrostatic pressure reached 60 MPa,the water absorption was above 30.19%,and the physical and mechanical properties of composites were weakened.When the hydrostatic pressure was lower than 40 MPa,the mechanical properties and thermal conductivity of composites were almost unchanged.Therefore,the composites with 50 vol%HGM can be used for ITPCoring operations in deep environments with the highest hydrostatic pressure of 40 MPa.Finally,to further understand the temperature preserved performance of composites in practical applications,the temperature preserved properties were measured.An unsteady-state heat transfer model was established based on the test results,then the theoretical change of the core temperature during the coring process was obtained.The above tests results can provide a research basis for deep rock in-situ temperature preserved corer and support accurate assessment of deep petroleum reserves.

Analysis of Mechanical Properties of Injection Molded Short Glass Fibre (SGF)/Calcite/ABS Composites

Acrylonitrile-butadiene-Styrene (ABS), with and without calcium carbonate (calcite) particles,was used as the matrix for reinforcement with as-received short-glass fibres (were originallytreated by the manufacturer) and sized short-glass fibres with two amino-silane coupling agents.The calcite particle content is 0, 11.7 and 23.5 vol. pct for the matrices. The glass fiber contentis 0, 10 and 15 vol. pct. The matrix materials and corresponding composites were compoundedusing a twin screw extruder and dumbbell-shaped tensile bars were prepared with an injectionmolding process. The tensile and flexural properties as well as the unnotched and notchedCharpy impact energies of short glass fibre/calcite/ABS composites were studied in this paper.The effects of fibres, fibre surface treatments and particles on these mechanical properties ofthe composites were discussed in detail. An importarit information was obtained, which is thatthe tensile and flexural strengths of hybrid SGF/calcite/ABS composites are the same as thoseof corresponding fibre composites when the ratio of the interfacial adhesion strength betweenparticles and matrix to that between fibres and matrix is higher than certain value. otherwise theformer are lower than the latter.

Electromagnetic wave absorption and mechanical properties of SiC nanowire/low-melting-point glass composites sintered at 580°C in air

Si C nanowires are excellent high-temperature electromagnetic wave (EMW) absorbing materials. However, their polymer matrix composites are difficult to work at temperatures above 300℃, while their ceramic matrix composites must be prepared above 1000℃ in an inert atmosphere. Thus, for addressing the abovementioned problems, SiC/low-melting-point glass composites were well designed and prepared at 580℃ in an air atmosphere. Based on the X-ray diffraction results, SiC nanowires were not oxidized during air atmosphere sintering because of the low sintering temperature. Additionally, SiC nanowires were uniformly distributed in the glass matrix material. The composites exhibited good mechanical and EMW absorption properties. As the filling ratio of SiC nanowires increased from 5wt%to 20wt%, the Vickers hardness and flexural strength of the composite reached HV 564 and 213 MPa, which were improved by 27.7%and 72.8%, respectively, compared with the low-melting-point glass. Meanwhile, the dielectric loss and EMW absorption ability of SiC nanowires at 8.2–12.4 GHz were also gradually improved. The dielectric loss ability of low-melting-point glass was close to 0. However, when the filling ratio of SiC nanowires was 20wt%, the composite showed a minimum reflection loss (RL) of-20.2 dB and an effective absorption (RL≤-10 dB) bandwidth of2.3 GHz at an absorber layer thickness of 2.3 mm. The synergistic effect of polarization loss and conductivity loss in SiC nanowires was responsible for this improvement.

Investigation of Microstructure and Phase Composition of Chromic Oxide, AZS/Cr and High-alumina Refractories after Exposure of Basalt and Aluminaboronsilicate Glasses Melts

The microstructure and phase composition of high-alumina,chromic oxide,and AZS/Cr refractories containing 30%and 60%(by mass)Cr_(2)O_(3) after exposure to aluminaboronsilicate glasses and basalt melts depending on the type of melts and temperature have been studied.The mechanisms of refractory corrosion by the used melts and the factors contributing to the inhibition of corrosion development have been investigated by the method of petrographic analysis.On the basis of obtained results,the use of high-alumina,chromic oxide,and AZS/Cr refractories in the sections of glass furnace linings,experiencing the intensive impact of aluminaboronsilicate glasses and basalt melts,has been confirmed and scientifically substantiated.

Crystallization and dielectric properties of lead-free glass-ceramic composites with Gd_2O_3 addition

Lead-free glass-ceramic composites in barium sodium niobate silica system with Gd2O3 addition were synthesized through melt-casting fol-lowed by controlled crystallization technique. Crystallization and dielectric properties of the Gd2O3 adding glass-ceramic composites were investigated. With the increase in the concentration of Gd2O3, the glass transition temperature and the crystallization temperature of the pre-cursor glass shift towards the higher temperature. The crystallization behavior that occurred during the heat treatment procedure leads to the enhancement of dielectric constant. All the three compositions of glass-ceramic composites exhibit ferroelectricity when tested at room tem-perature. Both the values of the remanent polarization and coercive field are enhanced regularly with the gradual increase in the concentration of Gd2O3 additive under the same testing field.