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3D printing has witnessed a remarkable surge in popularity due to its flexibility in design and adaptability as a manufacturing technique to nearly each industrial area. This study focuses on harnessing the technological versatility of 3D printing by utilizing both standard poly lactic acid (PLA) and copper powder‐doped PLA to fabricate intricate structures through a layer‐by‐layer additive manufacturing process. The other innovation introduced here lies in the postprocessing step, which involves salt remelting. The mechanical properties of 3D‐printed standard test specimens undergo comprehensive assessment, encompassing bending and tensile evaluations, hardness measurements, density assessments, dimensional stability analyses, and wear resistance examinations. Utilizing copper powder‐doped PLA for the initial and final layers in XYZ‐oriented prints enables multimaterial printing, resulting in an ≈14% increase in tensile strength. Subsequently, subjecting this multimaterial composite to salt remelting elevates the strength enhancement to ≈16%, accompanied by a significant boost in rigidity by reducing voids in cross‐sectional area. In addition, scanning electron microscope images are captured, allowing for a detailed morphological analysis, which is then correlated with the findings of the various tests performed. This research unveils the potential of 3D printing technology in crafting materials with tailored mechanical properties, advancing its applicability in numerous industrial sectors. [ABSTRACT FROM AUTHOR]

Spark plasma sintering (SPS) is a new sintering method having shorter sintering time and higher densification speed than the traditional sintering methods. In this paper, the Si3N4/TiC ceramic tool material is sintered by SPS. The microstructure and mechanical properties of the material under different sintering parameters are compared. The sintering process of the material is then analyzed, and the best sintering parameters are obtained. Heat the material to 1600°C and keep the temperature for 15 min, then continue to heat to 1700°C and keep the temperature for 10 min, Si3N4/TiC ceramic tool material has high mechanical properties, its bending strength, fracture toughness, and Vickers hardness are 959 MPa, 8.61 MPa·m1/2, and 15.21 GPa, respectively. The scanning electron microscope (SEM) analysis shows that under this condition, the sintering additives and Si3N4/TiC material form the liquid phase, which makes the Si3N4 particles rearrange, dissolve, precipitate, and transform into rod shape β‐Si3N4. In addition, under the action of pulse current and external pressure, electric sparks are generated between TiC particles, which allows the material transfer and particle refinement. Therefore, the β‐Si3N4 has uniform grain size, and it is vertically and horizontally arranged in the structure, which makes the material have excellent mechanical properties. [ABSTRACT FROM AUTHOR]

In the present study, a new composite based on epoxy resin reinforced with Lygeum spartum L. fibers was prepared using compression molding technique. Chemical, mechanical as well as morphological analyses were carried out on the Epoxy/Lygeum spartum composite (Epoxy/LS) using ATR-FTIR, tensile and flexural tests, and SEM spectroscopy. An increase in the intensity of several bands associated to the main complements of vegetable fibers (cellulose, hemicellulose, and lignin) was showan using ATR-FTIR analysis. An improvement in the mechanical properties of this new material was observed, with respect to the neat epoxy resin. This was of the order of 117 % and 85 % for tensile and flexural modulus respectively, and of the order of 40 % and 9 % for tensile and flexural strength, correspondingly. A good fiber-matrix adhesion was also observed from tensile fracture surface of composite using scanning electron microscope (SEM). All the obtained results demonstrated the effectiveness of the Lygeum spartum fibers as reinforcement of composite materials. [ABSTRACT FROM AUTHOR]

As a rapidly developing additive manufacturing technology, fused deposition modeling (FDM) has become widespread in many industry fields. It can fabricate complicated geometries using filament of thermoplastic materials such as PP, polylactic acid, acrylonitrile butadiene styrene, etc. However, poor mechanical properties of raw materials limit their application. Poly-ether-ether-ketone is a type of special engineering plastic with high performance, which could be further reinforced by adding carbon fibers (CFs). During FDM process, the mechanical properties of printed parts are largely subject to careful selection of process parameters. To improve the mechanical properties of PEEK and CF/PEEK 3D-printed parts, the effects of various process parameters including building orientation, raster angle, nozzle temperature, platform temperature, ambient temperature, printing speed, layer thickness, infill density, and number of printed parts on mechanical properties were investigated. The tensile fracture interfaces of printed parts were observed by scanning electron microscope (SEM) to explain the influence mechanism of process parameters. In the single factor experiments, flat and on-edge specimens show the best tensile and flexural strength, respectively; the specimens with raster angle ±45° and 0° show the best tensile and flexural strength, respectively. When the nozzle temperature at 500°C, platform temperature at 200°C, ambient temperature at 150°C, printing speed is 20 mm/s, layer thickness is 0.2 mm, and infill density is 100%, the printed parts exhibit the best mechanical properties. [ABSTRACT FROM AUTHOR]

ZnS‐reinforced ZnS/ZnSe composites are prepared by chemical vapor deposition. Scanning electron microscope, transmittance, and bending strength are used to characterize the samples. The schematic diagram of the transmittance model of the double‐layer composite window is used to calculate the theoretical transmittance, and the measured value of the transmittance of ZnS/ZnSe composite material is in good agreement with the calculated value. The effects of interface layer on the optical and mechanical properties of materials are studied in detail. It is found that the interface can affect the transmittance of the composites, but it still maintains a high transmittance, and the influence of interface layer on the transmittance of visible band is more serious than that of infrared band. Moreover, the mechanical properties of the new composite material are significantly improved (35%). [ABSTRACT FROM AUTHOR]

Grain refinement is one of the most effective methods for strengthening steels, but grain refinement to 1 µm or less deteriorates the ductility considerably. To evade the strength-ductility trade-off, a lamellar-structured (LS) ultrafine-grained (UFG) dual-phase (DP) ferrite/martensite (F/M) steel was produced by warm rolling an intercritical annealed low-carbon martensite and subsequent air cooling in this paper. The microstructure is similar to a short fiber reinforced composite, and the highest strength (1432 ± 15 MPa) combined with a decent ductility (16.5 ± 0.5% elongation) is achieved in DP steel. Compared with conventional equiaxed coarse-grained (CG) and UFG DP counterparts, the LS martensite in UFG DP steel can produce extra strengthening effect and is also beneficial to ductility. And the short fiber theory can predict the strength very well. [ABSTRACT FROM AUTHOR]

The fabrication method of composite materials has significant influence on the mechanical properties of the materials. Establishment of proper bonding, dispersion and diffusion of reinforcement in the matrix are identified as principal characteristics which need to be taken care during the manufacturing of metal matrix composites. The current work has highlighted the impact of metal (Al) mixed dual size particle reinforcements (Al 2 O 3 (μm) & Si 3 N 4 (nm)) and the domination of silicon nitride nano particle in the composite system. The reinforcement powders were ball milled for 3 h. The matrix alloy used in this work was AA6061 which holds the applications in the construction of structures, aircraft and automobile bodies. The matrix alloy was melted and milled powders were added at 850 °C followed by stirring process. The tensile, Compression and Hardness tests were conducted to characterize the mechanical behavior of the prepared composites. The Optical Microscope and the Scanning Electron Microscopes were used to analyze the morphology of the as-cast and fractured surfaces. The composites of metal mixed reinforcements offered improved mechanical properties than the composites of unmixed reinforcement. Tensile characteristics [Ultimate Tensile Strength (72.3 MPa–153.2 MPa), yield strength (67 MPa–148 MPa), and ductility (2–8.3%)] were much influenced by pre mixed Si 3 N 4 nano particles and its volume fraction in composites. The composites with dual reinforcement have shown superior tensile behavior than single reinforcement. The compression behavior [compression strength (253–361.74 MPa)] and hardness of the composites were dominated by single reinforcement with premixed Al 2 O 3 particles. The dislocation density due to the presence of Si 3 N 4 nano particle and proper bonding of hard Al 2 O 3 particles in the matrix supported by Si 3 N 4 nano particles were observed as strengthening mechanism in the composites with dual reinforcement. [ABSTRACT FROM AUTHOR]

A new magnesium oxysulfate (MOS) cement was prepared with the modification of sodium malate. The microscopic morphology of MOS cement was examined by scanning electron microscope (SEM). X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) was used to characterize the crystalline degree and molecular structure of MOS cement. The characterization results indicated that quantities of 517 phase magnesium oxysulfate whiskers were detected in the modified MOS cement. The flexural strength and water resistance of MOS cement were increased by the addition of sodium malate and the mechanism was also discussed according to the characterization results mentioned above. [ABSTRACT FROM AUTHOR]

The potential of using of sub-microalumina/titanium particles as a reinforcement that can produce multifunctional polymer composites was explored. Novel multifunctional composites have been developed by incorporating sub-microalumina/ titanium particles into polyamide6. The composites were investigated for their thermal, viscoelastic, water uptake and mechanical properties, as a function of alumina/titanium concentration. A detailed study of the morphological observation by scanning electron microscope was used to correlate the microstructures to the mechanical properties. Flexural testing shows that the flexural modulus and strength of the composite are improved by 22%, and 15%, respectively, with incorporating 10 wt% alumina/titanium. In addition, the impact strength was improved by about 19%. Furthermore, 10 wt% alumina/titanium increases the interfacial shear strength of polyamide6 by about 23%. [ABSTRACT FROM AUTHOR]

Because of the superior chemical and mechanical properties of titanium, many surface treatments have been developed to alleviate its bioactivity limitations. Among all these, the procedures involving the modification of the surface of the titanium using liquid media have received more attention, because of their ability to modify all outer and inner pores of porous titanium implants. In this research, both rigid and porous titanium implants were surface treated using hydrogen peroxide and the effects of treatment on surface morphology and the weight change of the rigid implant and the mechanical properties of the porous implant were investigated using scanning electron microscope (SEM), balance, and compression tests, respectively. The results indicated that although this procedure was a corrosive phenomenon leading to the surface roughening of rigid samples and influencing cell adhesion positively, it also resulted in about 34% reduction in the mechanical properties of the porous titanium implant. [ABSTRACT FROM AUTHOR]

With the flourish development of energy-saving solutions for building, the demands of phase change material (PCM) modified building materials are urgently increasing. Herein, we report a novel route to prepare clay geopolymer mortar incorporated PCM by vacuum absorption method, where PCM is produced with paraffin as heat-absorbing material and expanded perlite as p supportive material by vacuum adsorption method. The paraffin immobilized in three-dimensional network structure during the process of phase change is evidenced by scanning electron microscope (SEM), different scanning calorimetry (DSC), compressive strength, dry density and thermal conductivity. The proportion of paraffin in the composite is 55.47% by mass, and the phase change temperature and latent heat were 35.59 °C and 96.77 J/g, respectively. The compressive strength, dry apparent density, and thermal conductivity coefficient were 8.0 MPa, 1678 kg/m 3 , and 0.46 W m −1 K −1 , respectively. [ABSTRACT FROM AUTHOR]

It is important to optimize the properties of a material for a particular application, hence, to find the suitable material for tribological applications, the wear and friction behaviour of AA5052in situcomposites with different kind of reinforcements have been investigated. For present study, threein situformed composites have been produced with different reinforcements namely Al3Zr, ZrB2and combination of both (Al3Zr + ZrB2) by direct melt reaction (DMR) technique. The as-cast composites and base alloy have been characterized by X-ray diffraction (XRD), optical microscopy, electron microscopy, tensile testing, hardness and dry sliding wear and friction tests. XRD results indicate the successful formation of second phase reinforcement particles in all composites. Wear test results indicate that the cumulative volume loss increases with an increase in sliding distance while coefficient of friction shows a fluctuating tendency, whereas with increasing applied load, wear rate shows an increasing trend while coefficient of friction shows decreasing trend. The variation of wear rate with composites indicates that the composite with multiple reinforcement (Al3Zr + ZrB2) has lowest wear rate among all as-cast composites and base alloy, while coefficient of friction is higher. The responsible mechanisms concerned with wear and friction results have been discussed in detail with the help of the observation on worn surface analysis by scanning electron microscope (SEM) and 3D-profilometer. All tribological results have been correlated with the microstructural properties, strength parameters and bulk hardness of the composites. [ABSTRACT FROM AUTHOR]

The influence of reinforcement particle size variation plays a major role on the properties of Al–SiCpcomposite. Therefore, this study aim to investigate the mechanical and wear performance of single particle size (SPS) and multiple particle size (MPS) Al–SiCpcomposite prepared by stir casting process. The SPS comprises three categories; fine (15 ?m), intermediate (40 ?m) and coarse (80 ?m) particle sizes and combination of the three sizes accounts for the MPS in the ratio 1:1:2, respectively. Oxidation of the SiCpand addition of 1 wt% Mg during composite processing resulted to interface reaction products such as MgO (magnesium oxide) and MgAl2O4(magnesium aluminate) which suppresses the potential formation of undesired Al3C4(aluminium carbide). The study reveals that MPS composite improved the hardness and impact properties with enhanced wear performance compared to SPS composite. Characterization of the composite morphology and phases was performed using scanning electron microscope and X-ray diffraction analysis. This study provides an effective method of optimizing the properties of Al–SiCpcomposite by integrating MPS with low volume fraction of reinforcement phase. [ABSTRACT FROM AUTHOR]

Experimental and statistical analyses are represented considering the impact resistance and mechanical properties of self-compacting concrete reinforced with recycled Glass Fibre Reinforced Polymers (GFRP). Specimens were reinforced with recycled GFRP in three groups, including 0.25%, 0.75%, and 1.25% of fibre volume fractions. An extensive experimental program including two hundred and fifty two specimens were prepared and tested to characterize the impact resistance and mechanical properties of the reinforced self-compacting concrete with glass fibre reinforced polymers. Scanning Electron Microscope images were used to perceive the failure mechanism of recycled glass fibre in the matrix. Then, the relatively large and reliable collected data from the experimental tests was used to start statistical and analytical analysis. The results showed that adding recycled glass fibre reinforced polymers results in improving the impact resistance and mechanical properties of the reinforced self-compacting concrete with glass fibre reinforced polymers. Moreover, the statistical data analysis revealed that the impact resistance and mechanical properties of reinforced self-compacting concrete follow a normal distribution. Furthermore, some equations were developed to correlate the impact resistance of the reinforced self-compacting specimens to the mechanical properties with high values of coefficient of determination. [ABSTRACT FROM AUTHOR]

In this paper, laser-arc hybrid welding of 10 mm thick low-thermal-expansion superalloy GH909 components was carried out to obtain a joint with good performance. This investigation was conducted using an optical microscope, scanning electron microscope, energy diffraction spectrum and other methodologies. The results showed that weld joints with a desirable wineglass-shaped weld profile can be obtained employing appropriate process parameters. The different grains in between the upper central seam and the bottom seam were associated with the temperature gradient, the pool’s flow and the welding thermal cycle. MC-type carbides and eutectic phases (γ+Laves) were produced at grain boundaries due to the component segregation during the welding process. In addition, γ′ strengthening phase presented in the interior of grains, which kept a coherent relationship with the matrix. The lowest hardness value occurred in the weld center, which indicated that it was the weakest section in the whole joint. The average tensile strength of the joints reached to 632.90 MPa, nearly 76.84% of the base metal. The fracture analysis revealed that the fracture mode of the joint was ductile fracture and the main reason for joint failure was as a result of the occurrence of porosities produced in the weld during the welding process. [ABSTRACT FROM AUTHOR]

Coarse grained WC–10(Co, Ni) cemented carbides with different Ni contents were fabricated by sintering-HIP and cyclic sintering at 1450 °C. The effects of Ni addition and cyclic sintering on the microstructures, magnetic behavior and mechanical properties of coarse grained WC–10(Co, Ni) cemented carbides have been investigated using scanning electron microscope (SEM), magnetic performances tests and mechanical properties tests, respectively. The results showed that the mean grain size of hardmetals increases from 3.8 μm to 5.78 μm, and the shape factor Pwc decreases from 0.72 to 0.54, with the Ni content increases from 0 to 6 wt.%. Moreover, the W solubility reaches the highest value of 10.33 wt.% when the Ni content is 2 wt.%. The hardness and transverse rupture strength of WC–8Co–2Ni are 1105 HV 30 and 2778 MPa, respectively. The cyclic sintering is conducive to increase the WC grain size of WC–10(Co, Ni) and improves the transverse rupture strength of WC–10Co without compromising the hardness of alloys. [ABSTRACT FROM AUTHOR]

This paper aims at improving the mechanical properties of coir fiber reinforced polyester composites through impregnation of rice husk and boiled egg shell in polyester matrix. The composites sheets were manufactured by varying the fabrication parameters such as fiber length, particulate content and fiber content. The mechanical properties of the fabricated composites were determined as per ASTM standards and the effects of fiber length, particulate content and fiber content on mechanical properties of rice husk and boiled egg shells impregnated coir - polyester composites were studied. Scanning electron microscope analysis was used to characterize the fracture behavior of the composites. The investigation witnessed the improvement in mechanical properties on addition of rice husk particulate in coir fiber reinforced polyester composites. Similarly the addition of boiled egg shell in to the composites has enhanced mouldability of the composites. The SEM investigation evidenced the arrest of crack propagation and voids formation on addition of rice husk and egg shell particulates in polyester matrix. This study confirmed the possibility of using rice husk and boiled egg shell impregnated coir fiber reinforced polyester composites in low load bearing applications. [ABSTRACT FROM AUTHOR]

Analysis of the results of the microstructure and the mechanical properties change in AA1050 aluminum alloy of technical purity processed using ECAP (Equal Channel Angular Pressing) and KoBo deformation methods are presented in the paper.. ECAP process was performed according to Bc scheme in the range from 1 up to 10 passes. Changes of microstructure were analyzed using scanning electrone microscope equipped with electron backscattered diffraction (EBSD) system. Microstructure and fraction of high-angle grain boundaries in KoBo processed samples were similar to those observed in ECAP processed samples after four passes. The most significant microstructure refinement was observed in ECAP processed sample submitted to 10 passes. In ECAP method the systematic increase of mechanical properties was observed along with increase of deformation degree. [ABSTRACT FROM AUTHOR]

A new artificial reef concrete (NARC) with sulphoaluminate cement, marine sand and sea water et al. was proposed. The effect of cement type, sand type and water type on the workability (namely slump, slump loss cohesiveness, water retention), mechanical properties namely compressive strength, splitting tensile strength and dynamic elastic modulus) and affinity (namely surface initial pH value and the leaching rate of alkaline material in concrete) of concrete was studied. The microstructure of concrete was detected by X-ray diffraction, scanning electron microscope and pore structure analyzer, respectively. The studies show that NARC has superior workability, mechanical properties and affinity compared to ordinary Portland cement concrete with river sand and fresh water. Therefore, the feasibility of NARC in artificial reef is verified. [ABSTRACT FROM AUTHOR]

To optimize the mechanical properties of Ti(C,N)-based cermets used as tool materials, the cermets with different Ni–Co binder contents and Co/(Ni + Co) weight ratios were prepared. The effects of metal binder content and Co/(Ni + Co) ratio on the microstructure and mechanical properties of Ti(C,N)-based cermets were investigated by scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and measuring the transverse rupture strength (TRS), Vickers hardness ( HV ) and fracture toughness ( K IC ). The experimental results reveal that increasing Ni–Co binder content can increase the thickness of rim phases by improving the solid solution reaction and the wetting of hard phases. The cermets with 25 wt.% binder addition present good comprehensive mechanical properties, which is attributed to the moderate rim phases and uniformly distributed Ti(C,N) grains. The Co/(Ni + Co) weight ratios in binder have a great influence on the grain sizes and microstructure features of Ti(C,N)-based cermets, in virtue of the synergic effects between the wettability of Co and the solubilizing capacity of Ni on hard phases. The cermets with pure Co as binder exhibit optimal mechanical properties with a TRS of 1767 ± 81 MPa, a hardness of 12.26 ± 0.10 GPa and a K IC of 8.40 ± 0.47 MPa m 1/2 , which meet the requirements for tool materials. And the cermets with a Co/(Ni + Co) ratio of 0.2 have the second best mechanical properties with a TRS of 1848 ± 201 MPa, a hardness of 11.12 ± 0.40 GPa and a K IC of 9.43 ± 0.54 MPa m 1/2 , in which the lower hardness can be further improved by optimizing the compositions and sintering process. [ABSTRACT FROM AUTHOR]

ABSTRACT The fatigue life of ZEK100 magnesium alloy in the phosphate buffered solution for various immersion intervals was investigated by experiments and theoretical predictions. The biodegradable behaviours of ZEK100 magnesium alloy were also studied. Microstructure observation showed that the corrosion behaviours were characterized by pitting corrosion. The corrosion rate decreased a lot in the initial 7 d and then almost stayed unchanged. After 28 d immersion, the elastic modulus almost kept stable, while the yield strength and the ultimate strength decreased a lot, which indicated that corrosion had important effects on the tensile mechanical properties. It showed that the fatigue life of the samples under the same stress conditions decreased with increasing immersion time under the asymmetric stress-controlled cyclic loading. Considering the effect of corrosion on the material failure, a modified fatigue life model was proposed for magnesium alloy under corrosion. [ABSTRACT FROM AUTHOR]

Tensile tests were performed on two different natural fibre composites (same constituent material, similar fibre fraction and thickness but different weave structure) to determine changes in mechanical properties caused by various aqueous chemical treatments and whether any permanent changes remain on drying. Scanning electronic microscopic examinations suggested that flax fibres and the flax/polypropylene interface were affected by the treatments resulting in tensile property variations. The ductility of natural fibre composites was improved significantly under wet condition and mechanical properties (elongation-to-failure, stiffness and strength) can almost retain back to pre-treated levels when dried from wet condition. Preheating is usually required to improve the formability of material in rapid forming, and the chemical treatments performed in this study were far more effective than preheating. The major breakthrough in improving the formability of natural fibre composites can aid in rapid forming of this class of material system. [ABSTRACT FROM AUTHOR]

A study was carried out involving the filling of epoxy resin (EP) with bentonites and silica modified with polyhedral oligomeric silsesquioxane (POSS). The method of homogenization and the type of filler affect the functional and canceling properties of the composites was determined. The filler content ranged from 1.5% to 4.5% by mass. The basic mechanical properties of the hybrid composites were found to improve, and, in particular, there was an increase in tensile strength by 44%, and in Charpy impact strength by 93%. The developed hybrid composites had characteristics typical of polymer nanocomposites modified by clays, with a fine plate morphology of brittle fractures observed by SEM, absence of a plate separation peak in Wide Angles X-ray Scattering (WAXS) curves, and an exfoliated structure observed by TEM. [ABSTRACT FROM AUTHOR]

• This paper detailly reviews the progress of optical techniques developed for measuring mechanical properties of materials and devices at micro- and nano-scale. • The development of testing systems, including the equipment, clamping and loading are reviewed. • The deformation carries are reviewed, especially for the special materials and structures, such as the ultra-long carbon nanotubes and interface. • The principle, progress and typical application of the optical methods are reviewed, including the holography, speckle and moiré. • The new challenges and the possible directions of developing new methods are discussed. In the past three decades, we have witnessed the explosive development of micro/nano science and technology, where remarkable research efforts have been made in synthesizing of materials and fabricating of devices at micro- and nano-scale. The unusual mechanical behaviors of materials and devices with reduced their size and dimension pose the open questions to the researchers, which expand the framework of mechanics by advancing the theory, as well as modeling and experimental tools. Researchers in worldwide have been actively involved into this exciting area, making remarkable contributions to measure mechanical parameters and understand the mechanical behaviors of materials and devices at micro- and nano-scale. Micro optical method, as a full field, real-time and non-destructive measurement technique, is one of the earliest techniques used to measure the mechanical properties of materials at micro scale. So far, the optical methods are still an exciting research area in the field of mechanical property measurement of materials and devices at such small scale, even with the further reduction of the size of the research materials and devices, and their experimental platform has been promoted to various scanning microscope platforms, such as scanning electron microscope (SEM), scanning transmission electron microscope (STEM), atomic force microscope (AFM) and so on. This article reviews the research progress of optical techniques developed for the measurement of mechanical properties of materials and devices at micro- and nano-scale, with the aim to clarify the measurement principles and applications of optical methods in small scale, consisting of the experimental equipment, clamping and loading, deformation carriers or marks, optical methods including the holography, speckle and moiré, and finally to outline the perspectives in this fast-evolving field. [ABSTRACT FROM AUTHOR]

In this paper, we explore the glycosylation conditions (glucomannan content, reaction time, temperature and humidity) to probe the relationship between glycosylation and mechanical properties of soy protein isolate (SPI) film. The mechanical properties were characterized by studying the tensile strength (TS) and elongation at break (EB). Furthermore, degree of glycosylation, free glucomannan content, surface hydrophobicity, sulfhydryl groups content, lysine and arginine content of glycosylation soy protein with different reaction time were investigated to certify the significant effect of glycosylation on mechanical properties of soy protein film. What is more, the comparison of TS and EB, contact angle values and water vapor permeability of glycosylation SPI (GSPI), SPI and mixture of SPI and glucomannan films showed the excellence of GSPI. At the end, the analysis of scanning electron microscope was applied to reveal the effect of glycosylation on the structure of films. These results suggested that glycosylation with glucomannan is an ideal method to enhance the mechanical properties of soy protein isolate film. [ABSTRACT FROM AUTHOR]

The influence of heating mode on microstructure and mechanical properties of TiB2–based ceramic tool materials were studied. The chemical composition was detected by X-ray diffraction (XRD) and energy dispersive spectrometry (EDS), and the microstructure of the samples was observed using a scanning electron microscope (SEM). The brittle phases of Ni4B3and W2B were found in composite materials, which were harmful to the improvement of the mechanical properties of the composite. The results showed that the mode of direct heating-up not only can refine grains, but can also make the microstructure uniform, thereby improving the mechanical properties of materials. [ABSTRACT FROM AUTHOR]

A series of plastic materials for an organs injury stress assessment model use were prepared using a blend of potassium stearate (PS), sodium stearate (SS), polyvinyl alcohol (PVA) and paraffin liquid (PL) at various weight ratios. The mechanical properties of the materials were investigated via a compression test using Instron, and the results indicated that the PS/SS/PVA/PL blend with a weight ratio of 0·35∶0·35∶0·02∶0·28 had superior plastic deformation properties. The PS/SS/PVA/PL blend's weight ratio of 0·35∶0·35∶0·02∶0·28 was characterised by using Fourier transform infrared spectroscopy, a scanning electron microscope and differential scanning calorimetry. For a comparison, blend samples of PS/SS/PVA/PL with weight ratios of 0·68∶0∶0·2∶0·30 and 0∶0·68∶0·2∶0·30 were measured using the same methods. The results show that the plastic deformation mechanism is due to the optimal combination of weight ratio of the PS and the SS, and that the carbon chain in the PVA is a backbone of the slip function. [ABSTRACT FROM AUTHOR]

Polymer-modified concrete and fiber concrete are two excellent paving materials that improve the performance of some concrete, but the performance of single application material is still limited. In this paper, polymer-modified concrete with strong deformation and fiber concrete with obvious crack resistance and reinforcement effect were compounded by using the idea of composite material design so as to obtain a high-performance pavement material. The basic mechanical properties of high-content hybrid fiber–polymer-modified concrete, such as workability, compression, flexural resistance, and environmental durability (such as sulfate resistance) were studied by using the test regulations of cement concrete in China. The main results were as follows. (1) The hybrid fiber–polymer concrete displayed reliable working performance, high stiffness, and a modulus of elasticity as high as 35.93 GPa. (2) The hybrid fiber–polymer concrete had a compressive strength of 52.82 MPa, which was 31.2% higher than that of the plain C40 concrete (40.25 MPa); the strength of bending of the hybrid concrete was 11.51 MPa, 191.4% higher than that of the plain concrete (3.95 MPa). (3) The corrosion resistance value of the hybrid fiber–polymer concrete was 81.31%, indicating its adjustability to sulfate attack environments. (4) According to cross-sectional scanning electron microscope (SEM) images, the hybrid fiber–polymer concrete was seemingly more integrated with a dense layer of cementing substance on its surface along with fewer microholes and microcracks as when compared to the ordinary concrete. The research showed that hybrid fiber–polymer concrete had superior strength and environmental erosion resistance and was a pavement material with superior mechanical properties. [ABSTRACT FROM AUTHOR]

Objectives: The effect of gloss and heat on the mechanical behaviour of a recently launched glass carbomer cement (GCP, GCP dental) was evaluated and compared with resin-modified glass ionomer cements (Fuji II LC, GC and Photac Fil Quick Aplicap, 3M ESPE). Methods: 120 bar-shaped specimens (n = 20) were produced, maintained in distilled water at 37 °C and tested after one week. The GCP specimens were cured with and without heat application and with and without gloss. The flexural strength and modulus of elasticity in flexural test as well as the micro-mechanical properties (Vickers Hardness, indentation modulus, creep) of the top and bottom surface were evaluated. The amount and size of the fillers, voids and cracks were compared using a light and a scanning electron microscope. Results: In the flexural test, the resin-modified glass ionomer cements performed significantly better than GCP. Fuji II LC and Photac Fil (Weibull parameter: 17.7 and 14.3) proved superior reliability in the flexural test compared to GCP (1.4-2.6). The highest Vickers Hardness and lowest creep were achieved by GCP, whereas Fuji II LC reached the highest indentation modulus. The results of this study proved that relationships exist between the compositions, microstructures and mechanical properties of the cements. Conclusions: Heat treatment and gloss application did not influence the mechanical properties of GCP. The mechanical properties were basically influenced by the type of cement and its microstructure. Clinical significance: Considering the measured mechanical properties, there is no need of using gloss or heat when restoring teeth with GCP. [ABSTRACT FROM AUTHOR]

Carbon fiber (CF) / poly (ethylene terephthalate) (PET) composites were prepared with various contents (2–15wt%) of short carbon fibers. To investigate the effect of surface treatment of the CF on the mechanical properties of the composites, three specimens were prepared; those with short carbon fibers (called SCF), short carbon fibers oxidized with nitric acid (called NASCF) and the fibers oxidized with nitric acid and treated with silane coupling agent (called SCSCF). Flexural, tensile and impact tests were performed to observe mechanical behavior of the specimens. The morphology of the specimens was also studied with a scanning electron microscope (SEM). SCSCF composite had better mechanical properties than the other composites with the same content of carbon fibers since the coupling agent resulted in better interfacial adhesion between the fiber and the matrix. [ABSTRACT FROM AUTHOR]

In this work, the mechanical behavior of sintered waste material of ethylene-propylene-diene-monomer crumb rubber (EPDMCR) is analyzed, optimizing the temperature and compression pressure. The results obtained showed that an increase in temperature and compression pressure gives a significant improvement in the mechanical properties of the material. We later mixed the EPDMCR particles with different percentages of adhesives with the aim of further improving the mechanical performance obtained from the sintered particles. The adhesives used in this study were latex and polychloroprene, and the optimum mechanical performance obtained came from mixes with polychloroprene, using a mix with 50% adhesive. The study was concluded with an analysis of images of the material using a scanning electron microscope (SEM), in order to observe the EPDMCR–adhesive interaction. [ABSTRACT FROM PUBLISHER]

Effect of silicon carbide and aluminium oxide fillers on tension, flexural, compression, and impact properties of woven jute fabric reinforced epoxy composite has been investigated experimentally. Several laminates were prepared by hand lay-up technique by varying the percentage of filler addition. Tests (except impact) were conducted on computer interfaced universal testing machine as per ASTM standards. Impact tests were conducted on pendulum impact testing machine. The results of the tests indicated that addition of filler has significant effect on these properties. Laminate with 10 wt% of filler (based on resin) exhibited the highest properties. The properties were found to decrease beyond 10 wt% of filler loading. The mode of failure was also studied for selected samples using scanning electron microscope. [ABSTRACT FROM PUBLISHER]

Polypropylene (PP) sheets obtained through a two-step process (masterbatch method) were crosslinked by electron beam irradiation. The crosslinked PP sheets were foamed in an oven under different processing conditions. The effects of foaming temperature and time on the mechanical properties and cell structure of PP foams were studied. With the foaming temperature increasing and foaming time lengthening, both the compression modulus and compression strength dropped. Scanning electron microscope (SEM) was employed to study the morphology and cell structure of different samples and the related morphology parameters were acquired. The results showed there was an optimum temperature and time that produced the maximum expansion ratio or the minimum foam density. As foaming temperature or time increased, the cell size increased and the cell density decreased regularly. Excessively high foaming temperature and overly long foaming time caused the coalescence and even the collapse of the cells. [ABSTRACT FROM AUTHOR]

Abstract: The joining of two pieces of SiC-based ceramic materials (SiC or Cf/SiC composite) was conducted using Ti3SiC2 as filler in vacuum in the joining temperatures range from 1200°C to 1600°C. The similar chemical reactions took place at the interface between Ti3SiC2 and SiC or Cf/SiC, and became more complete with joining temperature increases, and with the consequent increased joining strengths of the SiC and Cf/SiC joints. Based on the XRD and SEM analyses, it turns out that two reasons are most important for the high joining strengths of the SiC and Cf/SiC joints. One is the development of layered Ti3SiC2 ceramic, which has plasticity in nature and can contribute to thermal stress relaxation of the joints; the other is the chemical reactions between Ti3SiC2 and the base materials which result in good interface bonding. [ABSTRACT FROM AUTHOR]

Abstract: 17-4PH stainless steel was plasma nitrocarburized at 500°C with and without rare earths (RE) addition. The nitrocarburized layers were characterized by optical microscope, scanning electron microscope equipped with an energy dispersive X-ray analyzer, X-ray diffraction, hardness tests and pin-on-disc tribometer. The results show that rare earths atoms can diffuse into 17-4PH steel surface and change the microstructure of the nitrocarburized layer. The incorporation of RE elements increases the layer thickness and the hardness of the nitrocarburized layer up to 29% and 70–120HV, respectively. The friction coefficients and wear rates of the nitrocarburized specimens are apparently lower than that of un-nitrocarburized one. The wear mechanisms of steel specimen plasma nitrocarburized with and without RE addition are different mainly due to the differences in the microstructure, the phase proportion and the hardness of the modified layer. [Copyright &y& Elsevier]

PVC/nano CaCO3 composites were prepared on Brabender Plasticorder. For comparison purposes, commercial CaCO3 composites were also prepared. Characterization of the nano CaCO3 and nanocomposites were done using scanning electron microscope (SEM) and transmission electron microscope (TEM). Their mechanical and thermal properties were also studied. Exfoliation was observed with the addition of different sizes of nano CaCO3 filled in PVC composites. Best properties were observed with 9 nm CaCO3 PVC composites. Tensile strength and modulus improved significantly even though the amount of addition of nano filler is low. Thermal properties of PVC/nanocomposites were found to be better compared to that of commercial filled CaCO3 in PVC composites. [ABSTRACT FROM AUTHOR]

Abstract: Mode I fracture toughness of SiC particle-dispersed ZrB2 matrix composite has been measured using DCDC specimen. Compression test results of the DCDC specimen show that the fracture toughness of the composite is independent of crack length with an average toughness . Optical microscope and SEM observations reveal a flat crack path and fracture surface with no significant toughening mechanisms in the composite either through grain boundary deflection or SiC particle introduction. Comparison with previous ZrB2 matrix composites, in addition to other short crack test methods, there is an agreement with the results between what this study has come upon with respect to previous work. [Copyright &y& Elsevier]

Abstract: Compressive mechanical behavior of a 3D needle-punched C/SiC composite at room temperature was investigated at strain rate ranging from 10−4 to 6.5×103 1/s using the electronic universal testing machine and the split Hopkinson pressure bar. The experimental results show the strain rate has slight influence on the mechanical property of the material. The dynamic compression strength obeys the Weibull distribution with the Weibull parameter m calculated as 8.19. Scanning electron microscope (SEM) images of the fracture surface of specimens tested at various strain rates indicate that the failure pattern of the material also varies with the strain rate. [Copyright &y& Elsevier]

Abstract: Micro-compression testing is a promising technique for determining mechanical properties at small length scales since it has several benefits over nanoindentation. However, as for all new techniques, experimental constraints influencing the results of such a micro-mechanical test must be considered. Here we investigate constraints imposed by the sample geometry, the pile-up of dislocations at the sample top and base, and the lateral stiffness of the testing setup. Using a focused ion beam milling setup, single crystal Cu specimens with different geometries and crystal orientations were fabricated. Tapered samples served to investigate the influence of strain gradients, while stiff sample top coatings and undeformable substrates depict the influence of dislocation pile-ups at these interfaces. The lateral system stiffness was reduced by placing specimens on top of needles. Samples were loaded using an in situ indenter in a scanning electron microscope in load controlled or displacement controlled mode. The observed differences in the mechanical response with respect to the experimental imposed constraints are discussed and lead to the conclusion that controlling the lateral system stiffness is the most important point. [Copyright &y& Elsevier]

In low-pressure cold spraying, compressed air is used as a process gas. The most important process parameters are temperature and pressure. In the Low-Pressure Cold Spraying (LPCS) system in this study, the maximum preheating temperature is 650 °C and pressure is 9 bar. Powders used in LPCS process contain alumina with metallic powders; therefore LPCS is the method to spray soft metallic coatings with ceramic hard phase for different application areas, e.g., thick coatings and coatings for electrical and thermal conduction and corrosion protection applications. The aim of this study was to investigate microstructure, denseness, and mechanical properties of LPCS Cu, Ni, and Zn coatings. LPCS coatings seemed to be dense according to Scanning Electron Microscope (SEM) studies but corrosion tests were needed to identify the existence of porosity. Through-porosity was observed in structures of the LPCS coatings. Bond strengths of LPCS Cu and Zn coatings were found to be 20-30 MPa, and hardness was high indicating reinforcement and work hardening. [ABSTRACT FROM AUTHOR]

Ultra-fine grained 1100 Al alloy was successfully produced by accumulative roll bonding (ARB) process. TEM investigation and SAD patterns showed that, after eight cycles of ARB, sheets were found to contain ultra-fine grains with high angle grain boundaries. The mechanical properties of the ARB processed (ARBed) 1100 aluminum alloy increased with increasing the number of ARB cycles. The elongation dropped abruptly at the first cycles. Wear properties were investigated using a pin on disk wear machine at ambient environment. Contrary to an expectation, the wear resistance of the ARBed Al alloy was less than the non-processed Al alloy. Morphologies of worn surfaces were studied by scanning electron microscope (SEM). [ABSTRACT FROM AUTHOR]

This study aimed to investigate the influences of stamping temperature (or molding temperature) on thermal properties of matrix, mesoscopic structures of fabric and effective macroscopic mechanical properties of composite materials through experimental characterization. The plain woven carbon fiber/polypropylene composite laminates were prepared by hot stamping at 190 °C, 220 °C and 250 °C, respectively. Thermal study was performed using differential scanning calorimeter and thermogravimetric analysis. The mesoscopic properties were characterized through microscope and scanning electron microscope (SEM). Tensile test and short beam shear test were conducted to evaluate macroscopic properties of the material. Effects of fabric structure on the crack initiation and propagation as well as local strain concentration of thermoplastic composite were investigated in detail using digital image correlation (DIC) technique. Relationships of process parameters, thermal characteristics, mesoscopic fabric structures and macroscopic mechanical properties of the carbon fiber reinforced polypropylene (CF/PP) materials were explored under different stamping temperatures. The experimental results revealed that with increase in processing temperature, the crystallinity of polypropylene (PP) matrix increased, and the interfacial adhesion between fiber and resin became strong, leading to increase in tensile modulus. Due to the change of resin viscosity, the aspect ratio, crimp angle and gap size of the fiber bundles also vary. The interfacial debonding was a main failure mode in CF/PP composites. This study is anticipated to provide fundamental understanding in how to tailor effective properties of composites through manufacturing process. [ABSTRACT FROM AUTHOR]

• The post-fire mechanical properties of corroded grade D36 marine steel are presented. • The distributions of corrosion products affect the post-fire properties of the steel. • 900 °C treatment significantly enhances the mechanical properties of the material. • The high temperature influences the microstructures and fracture morphologies. Corrosion and high temperature are two main detrimental factors that degenerate the mechanical properties and lead to decrease both in strength and durability of steel. The combined influence of corrosion and high temperature on the mechanical properties of grade D36 marine steel is proposed in this study. A series of tests were conducted to determine the post-fire mechanical properties of corroded marine steel. Specimens were corroded by a saltspray test, and then heated to 500 °C or 900 °C. Afterward, stress–strain curves, elastic modulus, yield stress and ultimate strength of the specimens were obtained from tensile coupon tests. Three-dimensional laser scanning was used to evaluate the impact of corrosion. The microstructure and fracture morphology analyses were carried out by metallographic microscope and scanning electron microscope (SEM), respectively. It was found that corrosion and high temperature have significant influence not only on the mechanical properties, but also on the microstructures and corresponding fracture morphology of grade D36 marine steel. [ABSTRACT FROM AUTHOR]

Abstract: Electrospinning is known to be a unique method to prepare continuous nanofibers. Its brevity and extensive application in obtaining non-woven membrane, nanofiber bundle or yarn have attracted increasing attention throughout the world. Especially, how to obtain aligned nanofiber array by a modified electrospinning process has been a hot topic in recent years. An annular collector with the cross-section of circle to obtain fibrous yarn through electrospinning, pre-drafting, and subsequent twisting was reported in this investigation. Fiber arrangement in bundle and mechanical properties of the yarn were given by scanning electron microscope and strength tester. Results showed that the pre-drafted bundle consisted of highly-aligned submicron fibers with the diameter from 750 to 1000 nm. In addition, it was found that the yarn is unsuitable for clothing, but may be applied in many other fields, such as composites, tissue engineering, and catalyst materials. [Copyright &y& Elsevier]

A comprehensive and comparative experimental study has been conducted to investigate the effect of thermal-oil ageing on mechanical, thermal and internal structural properties of E-glass fibre/epoxy composite materials. E-glass fibre/epoxy composite specimens were divided into 8 groups according to the certain experimental ageing temperatures. The temperature values were selected as −10, 25, 50, 80, 100, 120 and 140 °C, while the values of the ageing duration were selected as 24, 168, 360, 720 and 1080 h. Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) tests were performed to determine the thermal properties, tensile tests were used to detect the mechanical properties and a Scanning Electron Microscope (SEM) was used to illustrate the changes in the internal structure of the composites. As a result of this work, unexpectedly no alteration was observed in the mechanical properties of the specimens aged at −10 °C; however, ageing at 120 and 140 °C reduced the maximum load carrying capacities (LCCs) of the specimens especially for further ageing exposure times. Furthermore, the thermal stability of the specimens aged at −10 °C increased with the increasing thermal ageing duration while, for the other thermal ageing temperatures, the thermal stability showed a decreasing trend as the thermal ageing exposure time increased. [ABSTRACT FROM AUTHOR]