Journal articles: 'Micro composite'

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Senthilkumar, R., N. Arunkumar, and M. Manzoor Hussian. "Effects of Micro and Nano-Size Al₂O₃ Particle Reinforcement on Mechanical Behaviour of Extruded Aluminum Alloy Matrix Composite." Applied Mechanics and Materials 787 (August 2015): 617–21. http://dx.doi.org/10.4028/www.scientific.net/amm.787.617.

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Aluminum alloy (AA2014) matrix composites reinforced by different weight percentage of aluminum oxide (Al2O3) in micro and nano sizes were fabricated through powder metallurgy route followed by hot extrusion process. Seven different aluminium composites with varying percentages of nano and micron sized alumina particles varying from 1% to 10% were evaluated in addition to monolithic alloy. The microstructure of nano-composite and monolithic alloys were examined by optical microscope and scanning electron microscope (SEM) equipped with an energy dispersive X-ray analysis (EDAX). In addition, the effects of weight fraction of the reinforcement matrix on mechanical properties were evaluated. The results have indicated that, a significant improvement in hardness of the nano composite was found in case of nano-composite with 8% of micro Al2O3 and 2% of nano Al2O3 particles by the addition of reinforcement.

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Senthilkumar, R., N. Arunkumar, M. Manzoor Hussian, and R. Vijayaraj. "Study of Microstructure and Mechanical Properties of Sintered Aluminum Alloy Composite Reinforced with Al₂O₃ Nanoparticles." Advanced Materials Research 849 (November 2013): 62–68. http://dx.doi.org/10.4028/www.scientific.net/amr.849.62.

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In this research, aluminum alloy AA2014 matrix composites reinforced with micron (10% wt 5% wt) and nanoparticles (1% wt 5% wt) of Al2O3were fabricated through powder metallurgy method. Optimum amount of reinforcement were determined by evaluating mechanical properties like micro-hardness and compressive strength of composites. The composite samples were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results reveal that the composites containing 2% wt of nanoAl2O3and 8 % micro Al2O3reinforcement has homogenous microstructure as well as superior mechanical properties.

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Chen, L., R. Ballarini, H. Kahn, and A. H. Heuer. "Bioinspired micro-composite structure." Journal of Materials Research 22, no. 1 (January 2007): 124–31. http://dx.doi.org/10.1557/jmr.2007.0016.

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This paper presents the design, fabrication, and mechanical testing of a bioinspired composite structure with characteristic dimensions on the order of tens of microns. The microarchitecture, designed and fabricated using microelectromechanical systems (MEMS) technology, involves two distinct length scales and represents the first attempt at mimicking the crossed-lamellar microstructure of molluscan shells such as the giant Queen conch, Strombus gigas, which contains features with dimensions spanning five distinct length scales. The displacement control capabilities of a nanoindenter enabled the observation of the graceful failure of the micro-composite under three point bending and, in turn, the measurement of its post-peak load–displacement response and work of fracture.

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Lan, Xin, Weimin Huang, and Jinsong Leng. "Shape Memory Effect in Micro-Sized Shape Memory Polymer Composite Chains." Applied Sciences 9, no. 14 (July 22, 2019): 2919. http://dx.doi.org/10.3390/app9142919.

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Since the shape memory effect (SME) has been confirmed in micron and submicron sized polyurethane (PU) shape memory polymer (SMP), it might be used in novel micro/nano devices even for surgery/operation inside a single cell. In this study, micron sized protrusive PU SMP composite chains are fabricated via mixing ferromagnetic nickel micro powders with PU SMP/dimethylformamide solution and then cured under a low magnetic field. Depending on the amount of nickel content, vertical protrusive chains with a diameter from 10 to 250 µm and height from 200 to 1500 µm are obtained. The SME in these chains is investigated to confirm the SME in SMP composites at microscale. An array of such protrusive chains may be utilized to obtain re-configurable surface patterns in a simple manner for applications, such as remarkable change in wetting and friction ability. Finally, its potential applications for micro electro mechanical systems (MEMS) and biomedical device are proposed.

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Li, Duo Sheng, X. L. Zhou, A. H. Zou, X. Z. Hua, G. Z. Ye, and Q. J. Chen. "Study on Micro-Deformation Behavior of Sicp/Al Composites at Low Stress." Advanced Materials Research 426 (January 2012): 147–50. http://dx.doi.org/10.4028/www.scientific.net/amr.426.147.

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In this paper, SiCp/Al composites were fabricated by spontaneous infiltration technology. The micro-deformation behavior (MDB) of low tress in some silicon carbide particulate reinforced aluminum composites (SiCp/Al composites) was investigated experimentally. The microstructure, micro-deformation of samples was analyzed by OM and WDW-50 respectively. The results show that, in aluminum matrix with incorporating SiCp, the distribution of SiCp was uniform. In the same other conditions, SiCp size of the composite plays an important role on MDB at low stress, and the micro-deformation performance of the SiCp/Al composite increases with decreasing of SiCp size. MDB of composites at low stress deeply depends on the matrix material, and MDB increases with increasing of the matrix strength. It was also found that, the micro-deformation of SiCp/Al composite was negative value in the early stages of low tensile stress, and the phenomenon can be explained by strain relaxation.

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Senthilkumar, R., N. Arunkumar, M. Manzoor Hussian, and R. Vijayaraj. "Studies on Mechanical Properties and Microstructure of Al₂O₃ Reinforced AA5083 Matrix Composite ." Applied Mechanics and Materials 592-594 (July 2014): 749–54. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.749.

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The expectations over novel composite materials have been increased especially in automotive and aerospace applications due to its superior weight to strength ratio and tailored mechanical properties. In this frame work, aluminum alloy AA5083 alloy matrix reinforced with micron (10% wt – 5% wt) and nanoparticles (1% wt – 5% wt) of Al2O3.The composite samples were fabricated through powder metallurgy route. Optimum amount of reinforcement were determined by evaluating mechanical properties like micro-hardness and compressive strength of composites. The characterizations were probed by Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD) methods. The results reveal that the composites containing 2% wt of nanoAl2O3and 8 % micro Al2O3reinforcement witnessed superior mechanical properties due to its combined effect of concentration and particulate scale and the great isotropic behavior was achieved by homogenous dispersion of reinforcement in the matrix phase.

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Sukhavattanakul, Pongpat, Lerpong Jarupan, and Chiravoot Pechyen. "Structures and Properties of Isotactic-Polypropylene/Synthesized Micro Cellulose Tray: Effects of Micro Cellulose Loading." Advanced Materials Research 626 (December 2012): 716–20. http://dx.doi.org/10.4028/www.scientific.net/amr.626.716.

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Cellulose was derived from cotton fabric waste. Composites of microcellulose fibers (MC) and isotactic polypropylene (i-PP) was prepared by melting and mixing, and maleic anhydride grafted polypropylene (MA-g-PP) was used as compatibilizer. The MC was blended in different ratios up to 20 phr with i-PP using corotating twin-screw compounder and then a forming of trays was done by injection molding. Effects of MC on mechanical properties of i-PP were investigated. Changes in mechanical and morphological properties with different MC loading were discussed. The composite of i-PP/MA-g-PP/MC rendered better results in comparison with the i-PP/MC composite. The compressive strength and modulus of i-PP/MC composites increased with the addition of 20 phr MC. The i-PP/MA-g-PP/MC-20phr composites showed higher compressive strength and modulus than the i-PP/MC-20 phr without MA-g-PP due to increased interfacial interaction between MC and i-PP matrix. Thermal properties of i-PP/MC composites with and without MA-g-PP were not significantly different from pure i-PP. In conclusion, MC derived from cotton fabric waste could be used as a reinforcing agent for manufacturing thermoplastic.

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Hu, Haitao, Xiaohong Zhang, Dingping Zhang, Junguo Gao, Chunxiu Hu, and Yayun Wang. "Study on the Nonlinear Conductivity of SiC/ZnO/Epoxy Resin Micro- and Nanocomposite Materials." Materials 12, no. 5 (March 5, 2019): 761. http://dx.doi.org/10.3390/ma12050761.

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To investigate the inhomogeneous distribution of electric fields in insulating equipment and components, five nonlinear-conductance composite materials based on epoxy resin (EP) (nano-SiC/EP, nano-ZnO/EP, micro-ZnO/EP, nano-SiC/ZnO/EP, and nano-micro-SiC/ZnO/EP), were prepared using nano-SiC, nano-ZnO, and micro-ZnO particles as fillers. The mass fractions of the inorganic fillers were 1, 3, and 5 wt%, respectively. The direct current (DC) voltage characteristics of the composites showed that the electrical conductivities and nonlinear coefficients of the composites utilizing single-filler types increased with increasing inorganic filler content. Under the same conditions, the conductivity and nonlinear coefficient of SiC/EP were both larger than those of the nano-ZnO/EP and micro-ZnO/EP. However, the nonlinear coefficient of the composites was significantly affected by the simultaneous addition of the two inorganic fillers, micro-ZnO and nano-SiC. When the content ratio of micro-ZnO to nano-SiC was 2:3, the nonlinear coefficient of the composite reached a maximum value of 3.506, significantly higher than those of the other samples. Compared with the nano-SiC/EP, micro-ZnO/EP and nano-ZnO/EP composites with 5 wt% inorganic filler, the nonlinear coefficient of the two-filler composite was greater by a factor of 0.82, 2.48, and 5.01, respectively.

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Rajasekhar, Reshma, Baby James, Minimol K. Johny, and Jose Jacob. "Evaluation of the effect of two commercially available non-alcoholic mouth rinses on the microhardness of composite material - An invitro study." Current Dental Research Journal 1, Issue 1 (May 30, 2019): 14–21. http://dx.doi.org/10.12944/cdrj.01.o1.03.

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Composites have been widely used for anterior as well as posterior restorations due to increased aesthetic demands. Composite restorations placed in patients oral cavity is subjected to masticatory load, pH changes and chemical effect due to mouthwashes, beverages, food etc and the detrimental effects associated with these challenges on the microhardness of composite has to be determined. The study was conducted to evaluate the effect of two commercially available non-alcoholic mouth rinses on the microhardness of micro-hybrid and nanohybrid composite resins. Forty disc-shaped composite specimens were made from each type of composite materials and were divided into 5 groups with 8 samples each, Group 1= Microhybrid+Chlorhex, Group2=Microhybrid + Hexidine, Group3= Nanohybrid + Chlorhex, Group4= Nanohybrid+ Hexidine, Group 5= Nanohybrid and Micro hybrid + artificial saliva(Control).The samples were immersed in mouthrinses for 24 hrs and microhardness was subsequently measured using a Vicker’s microhardness tester. There was no significant difference in microhardness values of tested composite resins in either mouth rinses when compared to composites immersed in artificial saliva. Non-alcoholic mouth rinses do not affect the microhardness of micro-hybrid and nanohybrid composites.

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Wang, Zhen Ting, and Hua Hui Chen. "Study on the Wear Resistance of Micro-Nanostructured WC Composite Coating Sintered by Induced Heating." Key Engineering Materials 280-283 (February 2007): 1489–92. http://dx.doi.org/10.4028/www.scientific.net/kem.280-283.1489.

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Micro-nanostructured WC composite coatings were successfully fabricated by induced heating sintering method on the surface of Q235 steel .The microstructure, micro-hardness and the wear resistance of the composite coatings were studied .The results show that the microstructure of induced heat layer is mainly composed of Ni-based solid solutions and WC particles. And there exists excellent metallurgical bonding between coating and substrate. The wear resistance of micro-nanostructured WC Composite Coatings is increased by 1.5 times on an average as compared with that of micron.

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Jiang, Long Tao, Gao Hui Wu, Min Zhao, Qiang Zhang, Norio Kouno, and Hideo Saito. "Effects of Particle Size on Microstructure of the Matrix Alloy in Aluminum Matrix Composites." Materials Science Forum 546-549 (May 2007): 1655–59. http://dx.doi.org/10.4028/www.scientific.net/msf.546-549.1655.

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Aluminum matrix composites, reinforced by 0.15μm and 5μm Al2O3 particles with 40% volume fractions were fabricated by squeeze casting technique. The microstructure characterization near the interfaces of Al2O3p/1070Al composites was investigated by SADP and HREM techniques. Results showed that high-density dislocations were generated in the 5μm-Al2O3p/Al composite due to the thermal mismatch stress. In contrast, the matrix of the 0.15μm-Al2O3p/Al composite appeared to be nearly free dislocations and some “micro distortion areas” of 1-5nm were observed, which was attributed to the dispersion of fine sub-micron particles and uniform distribution of the stress near the interfaces.

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12

Abdelkarim, M. F., L. S. Nasrat, S. M. Elkhodary, A. M. Soliman, A. M. Hassan, and S. H. Mansour. "Volume Resistivity and Mechanical Behavior of Epoxy Nanocomposite Materials." Engineering, Technology & Applied Science Research 5, no. 2 (April 20, 2015): 775–80. http://dx.doi.org/10.48084/etasr.536.

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Electrical and mechanical properties of polymer composite materials are investigated through the determination of resistivity and hardness for composites samples. Epoxy composite samples have been prepared with different concentrations of certain inorganic fillers such as; Titanium dioxide (TiO2) and Silica (SiO2), of various size (micro, nano and hybrid) to study the electrical and mechanical behavior. The volume resistivity reaches 3.23×1014 ohm.cm for the micro silica composite. Surface of composite material has been mechanically examined by hardness test. The results show that the resistivity of microcomposites and nanocmposites are increased with the decrease of filler concentration. But the resistivity of hybrid composites is increased with the increase of filler concentration. Maximum hardness value was obtained from hybrid silica composite with 0.1% filler concentration.

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13

Shou, D.-H., and J.-H. He. "Micro-composite fibres by electrospinning." Journal of Physics: Conference Series 96 (February 1, 2008): 012213. http://dx.doi.org/10.1088/1742-6596/96/1/012213.

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Mahendrakumar, N., PR Thyla, PV Mohanram, C. Raja Kumaran, and J. Jayachandresh. "Study on static and dynamic characteristics of nettle–polyester composite micro lathe bed." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 233, no. 2 (August 5, 2016): 141–55. http://dx.doi.org/10.1177/1464420716663568.

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Nowadays, natural fibre-reinforced composites find applications in almost all engineering fields. This work is an attempt to realise improvement in dynamic characteristics of micro lathe bed using Himalayan nettle (Girardinia heterophylla) polyester (NP) composite as an alternate material. In order to study and validate the improvements envisaged, a cast iron micro lathe bed is considered as reference. Numerical (FE) model of the cast iron micro lathe bed was developed and validated through experimental static and modal analysis. Finite element analysis of the micro lathe bed with the existing cast iron material as well as with nettle–polyester composite as alternate material was also carried out using worst case cutting forces, and based on the relative performances, the need for form design modification for the proposed material was identified. To enhance the bending and torsional stiffness of the nettle–polyester composite lathe bed, various cross sections and rib configurations were studied and the best among them was identified and the same was implemented in the nettle–polyester composite micro lathe bed design. Finite element analysis of the newly designed nettle–polyester composite micro lathe bed was performed and the improvements in dynamic characteristics were evaluated. The newly designed nettle–polyester composite micro lathe bed was fabricated and the predicted enhancement in static and dynamic characteristics was verified experimentally. The studies indicated that nettle–polyester composite could be considered as a suitable alternate to cast iron structures in machine tools.

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Zhai, Jian Wen, Ya Jun Wang, Jian Lou Deng, and Chang Gen Feng. "Preparation and Dielectric Properties of Cu/PVDF Composite Films." Advanced Materials Research 1035 (October 2014): 417–21. http://dx.doi.org/10.4028/www.scientific.net/amr.1035.417.

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nanoand micro size Cu were employed separately and investigated comparatively. Different volume fraction of Cu was added into PVDF film in order to investigate the content of filler effect on the dielectric properties of polymer composites. XRD and SEM were used to analyze the crystalline phase and microstructure of the films. The results show that two sizes of Cu have the same peak features, and with the continuous increase of the content of Cu, it disperse better in PVDF. The dielectric constant (ε) of the composite containing 16 vol% micro-CCTO filler is 16 at 100 Hz and room temperature, and its dielectric loss (tanδ) is only 0.15, which is substantially better than others. Besides, for 18 vol% nanoCu/PVDF composite tanδis 0.25 andεis 18 at 100 Hz. Moreover,εand tanδof nanoCu/PVDF composite are both higher than those of micro-Cu/PVDF. Analysis shows that the composites with nanoCu have higher dielectric constants, which is mainly from the interfacial polarization.

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Katsuki, Makoto, Soshu Kirihara, Hiroki Harada, and Kohei Yamase. "Process Visualization of Thermal Nanoparticle Spraying Using Micro Composite Fragments." QUARTERLY JOURNAL OF THE JAPAN WELDING SOCIETY 35, no. 2 (2017): 1s—4s. http://dx.doi.org/10.2207/qjjws.35.1s.

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Zan, Zhao, Ming Gang Wang, and Zhan Kui Zhao. "Effects of SPS Pulse Current on Interface of Al₉₀Mn₉Ce₁/ZrO₂ Micro-Cellular Structure Composites." Materials Science Forum 749 (March 2013): 61–66. http://dx.doi.org/10.4028/www.scientific.net/msf.749.61.

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Metal/ceramic composite materials with micro-cellular structure which is Al90Mn9Ce1 micron powders coated by 10 wt% ZrO2 nanosized powder is prepared by spark plasma sintering. Effects of the SPS pulse current on the sintering behavior and the composite interface structure is investigated via SEM, XRD, TEM and EDS. The experimental results show that the pulse current is the key factor to the formation of micro-cellular structure. When the Al90Mn9Ce1/ZrO2 composites are sintered by a large pulse current, the hot focus on ZrO2 nanopowder among Al90Mn9Ce1 alloy particles as well as Al90Mn9Ce1 alloy particle surface, because of the effect of spark plasma and the concentration of the skin effect in short-term. Dividing temperature field on the interface of micro-cellular structure is benefit for the local high-temperature sintering of the ceramic cell walls layer, and also for the diffusion and interfacial bonding between Al90Mn9Ce1 alloy cell body and the ZrO2 nanosintered cell wall, so as to achieve good sintering.

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Dong, Shao Ming, Yu Sheng Ding, Qing Zhou, and Akira Kohyama. "Microstructure and Mechanical Properties of 2D Tyranno SA/SiC Composites by Hot Pressing." Key Engineering Materials 353-358 (September 2007): 1489–92. http://dx.doi.org/10.4028/www.scientific.net/kem.353-358.1489.

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SiC/SiC composites were fabricated by hot pressing (HP) via liquid phase sintering (LPS) using carbon coated 2D woven Tyranno SA fabrics as reinforcement. Both nano-SiC and micro-SiC powders with sintering additives were used for matrix. The effects of preparation conditions on the microstructure and mechanical properties of the composites were characterized. Highly densified composite was obtained at 1780°C under 20MPa with nano-SiC particles. The strength and elastic modulus of the composite were enhanced. When micro-SiC powder was used, higher strength revealed for the composite sintered at 1780°C under 15MPa, although it was not densified enough. Higher sintering temperature (1800°C) is beneficial for the densification of the composite, but is not obvious for the improvement of mechanical properties.

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Odermatt, Reto, Matej Par, Dirk Mohn, Daniel B. Wiedemeier, Thomas Attin, and Tobias T. Tauböck. "Bioactivity and Physico-Chemical Properties of Dental Composites Functionalized with Nano- vs. Micro-Sized Bioactive Glass." Journal of Clinical Medicine 9, no. 3 (March 12, 2020): 772. http://dx.doi.org/10.3390/jcm9030772.

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Bioactive resin composites can contribute to the prevention of secondary caries, which is one of the main reasons for failure of contemporary dental restorations. This study investigated the effect of particle size of bioactive glass 45S5 on chemical and physical composite properties. Four experimental composites were prepared by admixing the following fillers into a commercial flowable composite: (1) 15 wt% of micro-sized bioactive glass, (2) 15 wt% of nano-sized bioactive glass, (3) a combination of micro- (7.5 wt%) and nano-sized (7.5 wt%) bioactive glass, and (4) 15 wt% of micro-sized inert barium glass. Hydroxyapatite precipitation and pH rise in phosphate-buffered saline were evaluated during 28 days. Degree of conversion and Knoop microhardness were measured 24 h after specimen preparation and after 28 days of phosphate-buffered saline immersion. Data were analyzed using non-parametric statistics (Kruskal–Wallis and Wilcoxon tests) at an overall level of significance of 5%. Downsizing the bioactive glass particles from micro- to nano-size considerably improved their capability to increase pH. The effect of nano-sized bioactive glass on degree of conversion and Knoop microhardness was similar to that of micro-sized bioactive glass. Composites containing nano-sized bioactive glass formed a more uniform hydroxyapatite layer after phosphate-buffered saline immersion than composites containing exclusively micro-sized particles. Partial replacement of nano- by micro-sized bioactive glass in the hybrid composite did not impair its reactivity, degree of conversion (p > 0.05), and Knoop microhardness (p > 0.05). It is concluded that downsizing bioactive glass particles to nano-size improves the alkalizing potential of experimental composites with no negative effects on their fundamental properties.

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Náhlík, Luboš, Zdeněk Majer, Kateřina Štegnerová, and Pavel Hutař. "Lifetime Assessment of Particulate Ceramic Composite with Residual Stresses." Key Engineering Materials 754 (September 2017): 107–10. http://dx.doi.org/10.4028/www.scientific.net/kem.754.107.

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A micro-crack propagation in particulate ceramic based composite was studied using finite element method (FEM). Subcritical crack growth (SCG) was numerically simulated under complex load conditions (mechanical loading and loading by internal residual stresses). The effect of residual stresses on the crack propagation was studied. Two-dimensional computational model of particulate ceramic composite with material properties corresponding to low temperature co-fired ceramics (LTCC) was developed. The results indicate that the presence of residual stresses significantly reduces values of stress intensity factor in the vicinity of composite surface and the direction of residual stresses around the particles contributes to the micro-crack deflection from the particles. The time to failure of the composite under mechanical loading was determined. Results obtained contribute to a better understanding of the role of residual stresses during micro-crack propagation in ceramic particulate composites.

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Liu, Yue, Chuan Zhen Huang, Han Lian Liu, Bin Zou, Peng Yao, and Liang Xu. "Effect of Nano-Additives on Microstructure and Mechanical Properties of Ti(C,N)-TiB₂-WC Composite Ceramic Cutting Tool Materials." Key Engineering Materials 589-590 (October 2013): 337–41. http://dx.doi.org/10.4028/www.scientific.net/kem.589-590.337.

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Ti(C,N)-TiB2-WC composite ceramic cutting tool materials with nano-scale additives Ni and Mo, and micro-scale additives Ni and Mo as sintering aids were sintered respectively at a temperature of 1550 °C for holding time of 1hour in vacuum by a hot-press technique. The effects of nano-scale additives Ni and Mo, and micro-scale additives Ni and Mo on microstructure and mechanical properties of composites were compared and investigated. It is concluded that the wettability of nano-scale Ni and Mo to the composites is better than that of micro-scale Ni and Mo. The nano-scale whiskers were found in the composite ceramic tool materials with nano-scale additives. The addition of nano-scale Ni and Mo instead of micro-scale Ni and Mo could make the ﬂexural strength and fracture toughness of Ti(C, N)-TiB2 –WC composites have a promotion, but could not make the hardness of the composites increase in this study.

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Kealley, Catherine S., Bruno A. Latella, Arie van Riessen, Margaret M. Elcombe, and Besim Ben-Nissan. "Micro- and Nano-Indentation of a Hydroxyapatite-Carbon Nanotube Composite." Journal of Nanoscience and Nanotechnology 8, no. 8 (August 1, 2008): 3936–41. http://dx.doi.org/10.1166/jnn.2008.188.

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The mechanical properties of pure synthetic hydroxyapatite and hydroxyapatite-carbon nanotube composites were examined. Vickers microhardness and nanoindentation using a Berkovich tipped indenter were used to determine the hardness, fracture toughness and Young's modulus of the pure hydroxyapatite matrix and the composite materials. Microscopy showed that for the composites produced the carbon nanotubes were present as discrete clumps. These clumps induced a detrimental effect on the hardness of the materials, while the fracture toughness values were not affected. This would be undesirable in terms of using the material for biomedical implant applications. It should be noted that the carbon nanotubes used contained free graphite. As the properties of the composite materials studied were not greatly improved over the matrix, it is speculated that if the graphite phase were removed from the reagent, this could in-turn enhance the properties of the material.

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Yamamoto, T., M. Chino, R. Tanaka, T. Ueyama, and K. Okazaki. "Evaluation of ferroelectric/ ferromagnetic composite by micro-composite designing." Ferroelectrics 95, no. 1 (July 1989): 175–78. http://dx.doi.org/10.1080/00150198908245199.

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Prokešová, Pavla, Nikolay Petkov, Jiří Čejka, Svetlana Mintova, and Thomas Bein. "Micro/Mesoporous Composites Based on Colloidal Zeolite Grown in Mesoporous Matrix." Collection of Czechoslovak Chemical Communications 70, no. 11 (2005): 1829–47. http://dx.doi.org/10.1135/cccc20051829.

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Composite materials containing micro- and mesopores are prepared under instantaneous hydrothermal treatment of initial solutions generally used for zeolite Beta and precursor solutions for mesoporous Al-MCM-41 material. The resulting composites are compared with pure, highly crystalline colloidal microporous Beta zeolite and hexagonally ordered mesostructured samples. The porosity and morphological features of the composite materials are influenced by the conditions of hydrothermal synthesis of the initial colloidal solutions used for the preparation of Beta seeds, as well as by the conditions of the synchronized crystallization of the final composites. The embedding of Beta seeds in the mesoporous silica matrix is possible via immediate heating of mesoporous precursor solutions with Beta seeds primarily formed. The composite materials contain either microcrystalline Beta nanodomains with sizes of about 5-10 nm surrounded by mesoporous material or defined Beta nanocrystals (20-40 nm), and at the same time connected with mesostructured material. The presence of highly crosslinked silicate framework walls and tetrahedrally coordinated aluminum in the composite material are confirmed by solid-state 29Si and 27Al MAS NMR spectroscopy. The concentration of Brønsted acid sites in the micro/mesoporous composites is increased substantially in comparison with pure mesoporous Al-MCM-41 material proven by FTIR acetonitrile-d3 adsorption study.

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Kwon, Soon Chul, Tadaharu Adachi, Wakako Araki, and Akihiko Yamaji. "Mechanical Properties of Nano/Micro-Silica Particles Bidispersed Epoxy Composites." Key Engineering Materials 345-346 (August 2007): 1507–10. http://dx.doi.org/10.4028/www.scientific.net/kem.345-346.1507.

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Mechanical properties of nano/micro-silica particles bidispersed epoxy composites were investigated based on experimental results. The composite specimens varied with different compositions of nano and micro-silica particles (240 nm and 1.56$m) were prepared with the constant volume fraction, 0.30. The thermo-viscoelastic properties for the composites and the neat epoxy measured in the temperature ranges from 123 K to 523 K and compared to theoretical results according to Lewis and Nielsen’s law with the maximum particle packing given by Ouchiyama and Tanaka’s model. In addition, fragility derived from the thermo-viscoelasticity measurements was used to characterize the strength and fracture toughness of the composites. From results, we found that the thermo-viscoelasticity of the composite was dependent on nano and micro-particles packing, and its strength and fracture toughness were effectively evaluated by fragility.

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DEHGHNIAN, C., and M. TAKESTANI. "A COMPARISON OF 85%W-15%CU COMPOSITES SYNTHESIZED BY NANO AND MICRO POWDERS." International Journal of Modern Physics: Conference Series 05 (January 2012): 574–80. http://dx.doi.org/10.1142/s2010194512002498.

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Two kinds of tungsten-copper composites with the composition of 85% W -15% Cu were synthesized using mechanochemically produced nano size and conventional micro size powders. The densification, mechanical and electrical properties of these composites was examined. It was found that the samples sintered from nanopowders had more densities and better physical and mechanical properties than those produced from micro sized powders. The micro W - Cu powder mixtures were pressed to 60 percent of its theoretical density but the nano composite powders were difficult to press due to its high friction energy and only reached to 30 percent of its theoretical density. The highest densities were obtained from nano composite mixtures at 1200°C.

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Fejjeri-Mezghanni, Meriem. "Silorane versus methacrylate composites: A comparative study of the micro-leakage." New Trends and Issues Proceedings on Advances in Pure and Applied Sciences, no. 9 (January 9, 2018): 58–65. http://dx.doi.org/10.18844/gjapas.v0i9.3017.

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This in vitro study aimed to evaluate the micro-leakage at the occlusal and cervical margins in class II cavities in permanent molars restored with a low shrink silorane resin composite (Filtek P90) applied with or without etching and two methacrylate-based composite resins (valux plus and Amelogen® plus). Two standardised class II box cavities were prepared in proximal surfaces of 60 sound non-fluorotic permanent molars which were divided into three groups of 20 each according to the type of composite. Group I: silorane-based composite (Filtek P90) in the mesial cavity and methacrylate-based microhybrid composite (Adper single bond 2/valux plus) in the distal cavity, Group II: silorane-based composite in the mesial cavity and silorane-based composite with previous etching in the distal cavity, and Group III: silorane-based composite in the mesial cavity and methacrylate-based micro-hybrid composite (PQ1 /Amelogen plus) in the distal cavity. The samples underwent an artificial aging with thermocycling. Root apices were sealed with transparent orthodontic resin and coated with transparent varnish except 1 mm around the restoration. The specimens were immersed in 1% methylene blue solution at room temperature for 48 hour. The samples were sectioned longitudinally in the mesiodistal direction and evaluated under a stereomicroscope at 20X. Scoring was done according to the depth of methylene blue penetration into the cavities. Statistical analysis of the data was performed using SPSS 17.0 software. Silorane-based composite resin showed less micro-leakage than the methacrylate-based composites. Etching improved the sealing ability of silorane restorations. Silorane-based composite preceded by etching had less micro-leakage among the other materials used in this in vitro study. Keywords: Silorane, methacrylate based composite, sealing, micro-leakage, class II cavity

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Li, Bao Feng, Jian Zheng, Xin Hua Ni, Lei Zhao, and Guo Hui Zhong. "Destruction Process Analysis of Laminated Ceramic Composites Based on APDL." Advanced Materials Research 168-170 (December 2010): 1107–10. http://dx.doi.org/10.4028/www.scientific.net/amr.168-170.1107.

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Laminated composites are the effective ways to toughen Al2O3 ceramics at present. The destruction process analysis of laminated ceramic composite is studied in this paper taking the Al2O3/ZrO2 ceramic composite as the example through the APDL programming. The micro model is established in ANSYS. And the failure stresses of each ply of the ceramic can be calculated by micromechanics method. Then the calculated failure stresses are compared to the simulated failure stresses. The micro model can visualize the destruction process of laminated ceramic composite. The failure criteria of composite material can be self-defining in ANSYS by using APDL. Some ideas of ANSYS application on composite material are given in this paper.

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Shamsuddin, Saidatulakmar, Shamsul Baharin Jamaludin, Zuhailawati Hussain, and Zainal Arifin Ahmad. "Fabrication and Characterisation of Powder Metallurgy Fe-Cr Matrix Composites Reinforced with Al₂O₃." Advanced Materials Research 686 (April 2013): 157–63. http://dx.doi.org/10.4028/www.scientific.net/amr.686.157.

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Abstract. Sintered powder metallurgy Fe based composites with advanced mechanical properties have been proposed as substitutes for more expensive cemented carbide and wrought alloys in many applications, especially as inexpensive wear resistance parts. The aim of this work was to fabricate and characterize a composite made of Fe-Cr as the matrix and Al2O3 particles as reinforcement. The composite was made by powder metallurgy method. The effect of different amount of binder, mixing duration, compaction pressure and sintering temperature has been investigated. Densification, micro hardness, wear resistance and compressive strength were used to characterize the composite. Powder metallurgy parameters that satisfy the composites quality have been optimized and result showed that higher sintering temperatures promote good sintering in the composites which produced better densification, higher reading of micro hardness, better wear resistance and compressive strength.

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Zhang, Yuan, and Yang Sheng Zhao. "Thermal Cracking Meso-Characteristic of LuHui Granite." Applied Mechanics and Materials 34-35 (October 2010): 355–59. http://dx.doi.org/10.4028/www.scientific.net/amm.34-35.355.

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Rock macro mechanic character is decided by rock composite and meso configuration. LuHui granite minerals composite, micro configuration and the rock thermal cracking in differ temperature are observed by micro-photometer in meso. LuHui granite is composited by kinds of minerals, and its minerals’ inhomogeneity is visible, the change of cementation among rock crystal grains, dislocation and micro cracking in crystal is produced in crystal grains under temperature. By means of experiment, the development of granite micro cracks and interior configuration, and change laws of micro cracks were observed. The quantitative analysis of the micro mechanism and laws of granite thermal crack was made, granite cracks number increases acutely in 240-260 degree C after a narrow range fluctuation in 80 degree C. Finally, the thermal cracks threshold of granite was determined primarily.

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Hu, Fu Qiang, Bo Yan Song, Ji Cheng Bai, P. J. Hou, H. C. Chen, and H. Zhang. "Micro-EDM for an Aluminium Matrix Composite." Key Engineering Materials 447-448 (September 2010): 233–37. http://dx.doi.org/10.4028/www.scientific.net/kem.447-448.233.

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The silicon carbide particle reinforced aluminium matrix composite (SiCp/Al) which is acknowledged as one of the most competitive metal matrix composites is now widely applied in aviation, aerospace and military fields, and its application is extending gradually. As a result of the hard and brittle SiC particles contained, mechanical machining of the material is difficult, but the method of electric discharge machining (EDM) has certain prominent advantages. In this paper, SiCp/Al was machined using micro-EDM. First, a Ф40μm × 4.1mm micro tool electrode of which the aspect ratio is up to 100 was made; and then, through experiment, the impact of open-circuit voltage and electrode material on processing speed and electrode wear was analyzed; finally, 28μm wide micro slits, micro square platform of 34μm long on each side and other micro three-dimensional structure were machined. Research and experimental results show that the use of appropriate micro-machining parameters and reasonable processing methods can improve processing performance to better achieve the micro-EDM of SiCp /Al.

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Bureš, R., M. Fáberová, and P. Kurek. "Microstructure and Mechanical Properties of Fe/MgO Micro-Nano Composite for Electrotechnical Applications." Powder Metallurgy Progress 18, no. 2 (November 1, 2018): 103–10. http://dx.doi.org/10.1515/pmp-2018-0011.

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Abstract The composite based on the microns iron size powder and MgO nanopowder was prepared using pressing followed by conventional and microwave sintering. Microstructure of the composite was investigated to evaluate the changes induced by different sintering technology. Young’s modulus, flexural strength and hardness of composites were analyzed to investigate the mechanical properties in dependence on MgO content, as well as in dependence on the sintering method. Microstructure and mechanical properties as well as functional magnetic properties of prepared composites are discussed in the paper. The main benefit of microwave heating found within process time shortening was confirmed in the case of the microwave sintered Fe/MgO composite.

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Wang, Ming Di, Shi Hong Shi, Hong Yu Wang, Cheng Feng Sun, and X. B. Liu. "Experimental Study on Single-Layer Laser Cladding Feeding by Micro/Nano Composite Powders." Key Engineering Materials 562-565 (July 2013): 958–63. http://dx.doi.org/10.4028/www.scientific.net/kem.562-565.958.

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Aimed at the lack of the cladding materials such as micro or nanopowder, the micro/nanocomposite powders prepared for experiment are feed directly, the key process parameters on the quality of the surface quality and microstructure analysis of the single-layer of laser cladding are studied in detail. Compared to the ordinary laser micro-cladding layer feeding by the micro powder, the cladding layer is more refined, which has more good mechanical properties. The results showed that: using reasonable parameters, the microstructure and macro-morphology of cladding layer with micro-nanocomposite powders feed directly are better than of micron powders.

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Thumsoontorn, Sineenart, Surasak Kuimalee, Budsabong Kuntalue, Suphakit Pintasiri, and Boonrat Lohwongwatana. "Microstructure and Direct Measured Micro-Strain by TEM of Hot Iso-Static Pressed Alumina-Titanium Carbide (Al₂O₃-TiC) Composite." Advanced Materials Research 983 (June 2014): 156–60. http://dx.doi.org/10.4028/www.scientific.net/amr.983.156.

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Alumina-titanium carbide composite (Al2O3-TiC) is one of advance ceramic matrix composites (CMC) that have been used in machining tool and tribology application because of its excellent mechanical properties. Powder processing is often a chosen method to produce this family of material, i.e. hot pressed (HP), hot iso-static pressed (HIP), and pressure-less sintering (PS). These manufacturing techniques convert sub-micron powder into dense bulk component. Al2O3-TiC composite has been prepared by HIP process, containing 65%vol Al2O3and 35%vol TiC. The powders were pressured and sintered at temperature between 1250˚C - 1650˚C. Thermal residual stress from Al2O3-TiC manufacturing process is conventionally unavoidable. The aim of this study is to investigate the microstructure of HIPped Al2O3-TiC composite and its residual micro-strain using transmission electron microscopy (TEM) with selected area electron diffraction pattern (SADP) analysis. The Al2O3-TiC composite was prepared by high-precision machining/grinding processes then focus ion beam milling process was used to section the TEM lamella. Microstructures, grain size and phases were determined by TEM and X-ray diffractometry (XRD). Micro-strains of {200}TiC, {111}TiC , {220}TiC and {012}Al2O3were investigated by SADP (Selected Area Diffraction Pattern). Our result revealed there is approximately 0.01 compressive strains distributed in Al2O3-TiC composite.

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Sarantinos, N., V. Kostopoulos, G. Di Vita, G. Campoli, and L. Bricout. "Micro-pins: the next step in composite–composite and metal–composite joining." CEAS Space Journal 11, no. 3 (May 23, 2019): 351–58. http://dx.doi.org/10.1007/s12567-019-00251-1.

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Sree Manu, K. M., P. S. Rahul, L. Ajay Raag, T. P. D. Rajan, M. Brahmakumar, and Bellampettu Chandrasekhar Pai. "Development of Al 319-Micro Silica Metallic Composite by Squeeze Infiltration Technique." Materials Science Forum 830-831 (September 2015): 489–92. http://dx.doi.org/10.4028/www.scientific.net/msf.830-831.489.

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The objective of present investigation is to synthesize porous micro silica based ceramic preform with varying composition of particles using burn out technique and processing of Al-Micro silica metal-ceramic composites by squeeze infiltration method. Direct squeeze infiltration of 319 aluminum alloy on micro silica preform is successfully carried out with the controlled process parameters of initial preform temperature, liquid metal superheat, squeeze pressure and its rate of application, and die temperature. The preform and composites are characterized using optical microscopy, electron microscopy, hardness and compression strength testing. Porous ceramic preform with more than 70% porosity has been fabricated by PEG as pore former. The infiltrated composite have shown uniform and complete infiltration of aluminum alloy in between micro silica particles.

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Yin, Ting, Bao Hong Tian, Yi Zhang, and Yong Liu. "Effect of TiC Content on the Microstructure and Wear Resistance of (Cu/50W)-TiC Composite Prepared by Spark Plasma Sintering." Advanced Materials Research 1052 (October 2014): 120–23. http://dx.doi.org/10.4028/www.scientific.net/amr.1052.120.

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The four different contents of (Cu/50W)- TiC composites were prepared by spark plasma sintering method. The density, relative density, micro-hardness and conductivity were determined, respectively. The microstructure of the composite was analyzed by SEM. The wear resistance was investigated by a QG-700 atmosphere and high temperature friction and wear tester. The results show that, when the content of TiC is 3%, the optimum comprehensive properties of the (Cu/50W)-3TiC composite are obtained. The density, micuo-hardness and conductivity of the composites are 98.7%, 113HV10 and 61.4%IACS, respectively. The wear mechanisms of the (Cu/50W)- TiC composites are mainly of micro-cutting wear and adhesive wear.

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Kumar, G. Ranjith, G. Rajyalakshmi, and Vijaya Kumar Manupati. "Surface Micro Patterning of Aluminium Reinforced Composite through Laser Peening." International Journal of Manufacturing, Materials, and Mechanical Engineering 7, no. 4 (October 2017): 15–27. http://dx.doi.org/10.4018/ijmmme.2017100102.

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Aluminium Composites have universal engineering applications because of their higher strength to weight ratio, ductility, and formability. However, in diverse applications, mechanical properties are the prerequisite at closer surface regions. Such localized changes without impacting various surface treatment approaches can attempt the bulk phase. Laser peening is an advanced surface engineering technique, which has been successfully applied to improve the surface morphology of the material. In this work, the authors focus on improving the surface properties of Al7075 composite through laser peening technique. The hardened layer was evaluated using surface integrity with optical microscopy, EDS, SEM and analysis of microhardness. Process parameters and resulting microstructures of Aluminium composite are summarized, along with the impact of laser peening on surface properties. Research results indicated that laser peening shows a significant influence on the final condition of the surface layer of Aluminium composite.

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Cui, Xiaobin, Kai Yan, Jingxia Guo, and Dong Wang. "Biomimetic micro-textures, mechanical behaviors and intermittent turning performance of textured Al2O3/TiC micro-composite and micro-nano-composite ceramics." Ceramics International 45, no. 16 (November 2019): 19934–47. http://dx.doi.org/10.1016/j.ceramint.2019.06.251.

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Tian, Shuai-Qi, Ming-Liang Qu, Li-Wu Fan, Zi-Tao Yu, and Jian Ge. "Thermal conductivity of aerated concrete (AC) composites containing micro-encapsulated phase change materials." MATEC Web of Conferences 282 (2019): 02033. http://dx.doi.org/10.1051/matecconf/201928202033.

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Aerated concrete (AC) was incorporated with micro-encapsulated phase change materials (PCMs) to form a novel PCM-composite AC with improved thermal storage capacity. RT25 paraffin was selected as the PCM and the composite materials were prepared by adding micro-encapsulated paraffin as an ingredient at various loadings. The effective thermal conductivity of the composite samples was measured at both 17 ºC and 35 ºC, while the paraffin was in solid and liquid phases, respectively. The volumetric heat capacity of the composites were also measured. Results showed that both the thermal conductivity and volumetric heat capacity increase upon adding the micro-encapsulated paraffin. However, they were found to decrease when further increase the paraffin loading. The maximum thermal conductivity and volumetric heat capacity were enhanced by approximately 35% and 30% when the paraffin loadings were 1% wt. and 3% wt., respectively. Since the increase of thermal conductivity leads to the deterioration of the thermal insulation performance, the composite samples with 3% wt. micro-encapsulated paraffin with lower thermal conductivity but the highest volumetric heat capacity was exhibited to be more appropriate.

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Vatin, Nikolai, Mirsayapov Ilizar, and Renat Nurmukhametov. "Composite helical micro pile’s bearing capacity." IOP Conference Series: Materials Science and Engineering 890 (August 13, 2020): 012037. http://dx.doi.org/10.1088/1757-899x/890/1/012037.

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42

Nessa, Meherun, and S. Motojima. "Effects of Additional Amount of Carbon Micro-Coils on the Electrical Properties of Carbon Micro-Coils Composite Sheet as a Tactile Sensor." Journal of Bangladesh Academy of Sciences 36, no. 2 (December 14, 2012): 177–86. http://dx.doi.org/10.3329/jbas.v36i2.12961.

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The morphology and electrical properties, tactile sensing properties of carbon micro-coils (CMC) composite sheet were examined. Frequency dependence of electrical parameters; inductance (L), capacitance (C) and impedance (Z) were measured on single and double-helix composite sheets. It was found that these parameters of carbon micro-coils/polysilicone composites extensively changed with the additional amount of CMC with polysilicone resine. It was also observed that the higher additional amount (0 - 10 wt%) of CMC is appropriate for high sensitivity as a tactile sensor. DOI: http://dx.doi.org/10.3329/jbas.v36i2.12961 Journal of Bangladesh Academy of Sciences, Vol. 36, No. 2, 177-186, 2012

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43

Majer, Zdeněk, and Luboš Náhlík. "Influence of Interphase Imperfection on Micro-Crack Behavior in Polymer Composites Filled by Rigid Particles." Key Engineering Materials 586 (September 2013): 194–97. http://dx.doi.org/10.4028/www.scientific.net/kem.586.194.

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In this paper a particulate composites with polypropylene matrix and rigid mineral fillers are studied. The polymer particulate composites are frequently used in many engineering applications. Due to the physical and chemical interaction between matrix and particles a third phase (generally called interphase) is formed. The composite is modeled as a three-phase continuum. The properties of particles and interphase have a significant effect on the global behavior of the composite. On the basis of fracture mechanics methodology the interaction of micro-crack propagation in the matrix filled by rigid particles covered by the very soft interphase is analyzed. The effect of the composite structure on their mechanical properties is studied here from the theoretical point of view. The properties of particles and matrix were determined experimentally. Conclusions of this paper can contribute to a better understanding of the behavior of micro-crack in polymer particulate composites with respect to interphase.

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Sheng, Yong Hua, Hu Min Dai, and Li Zhang. "Study on the CNTs Strengthening Metal Matrix Composite and its Properties." Applied Mechanics and Materials 80-81 (July 2011): 436–39. http://dx.doi.org/10.4028/www.scientific.net/amm.80-81.436.

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Using mixing casting method, in-situ composite technology, rapid solidification process and powder metallurgic method etc. can parpare metal matrix nano composites successfully. Comparing with other preparing methods, mixing casting method is with many advantages such as easy to manipulate, low cost, the composites obtained with better properties. CNTs strengthening metal matrix composites are with more dense organization and higher tensile strength, micro hardness, fatigue strength, and abrasive resistance etc. comparing with traditional metal matrix composites. So CNTs strengthening metal matrix composites are widely applied in industrial areas. In this article, the prepare methods of CNTs strengthening metal matrix composites are summed up, the micro organization and mechanical properties of CNTs strengthening metal matrix composites are described and whose future work is prospected.

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Muthukumar, M., J. Prasath, YM Desai, and NK Naik. "Mechanical behavior of unidirectional composites with hexagonal and uneven distribution of fibers in the transverse cross-section." Journal of Composite Materials 52, no. 22 (February 21, 2018): 2985–3000. http://dx.doi.org/10.1177/0021998318759742.

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Uneven distribution of fibers can adversely affect the mechanical behavior of unidirectional composites. A micromechanical model based on finite element analysis is presented to evaluate elastic and strength properties of such composites under normal loading. Analysis starts with identification of micro unit cells/micro repetitive unit cells and/or representative volume elements. Because of uneven distribution/random distribution of the fibers, fiber volume fraction can be different for different micro unit cells present at different locations in the transverse cross-section of the unidirectional composite. Configuration of the micro unit cell is worked out at the outset considering the fiber distribution having the hexagonal arrangement, but with different volume fraction at different locations. For such micro unit cells, elastic and strength properties are obtained based on finite element analysis starting with the elastic and strength properties of fiber and matrix. With the properties obtained for different micro unit cells, elastic and strength properties of the unidirectional composite with micro unit cells having hexagonal arrangement of fibers with different volume fraction at different locations in the transverse cross-section are determined. Further, elastic and strength properties are evaluated for micro unit cells with uneven distribution of fibers in the transverse cross-section.

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Majer, Zdeněk, and Luboš Náhlík. "Micro-Crack Propagation in Particulate Composite with Different Types of Matrix." Applied Mechanics and Materials 245 (December 2012): 138–43. http://dx.doi.org/10.4028/www.scientific.net/amm.245.138.

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Particulate composites with polymer matrix and solid fillers are one of important types of materials. Generally, these materials are usually used as construction materials, high-performance engineering materials or protective organic coatings. The main aim of a present paper is an estimation of the micro-crack behavior in the particulate composite with non-linear polymer matrix. The polymer matrix filled by magnesia-based mineral filler is investigated by means of the finite element method. A non-linear material behavior of the matrix was obtained from experiment as well as properties of mineral filler. Numerical model on the base of representative plane element (RPE) was developed. The results show that the presence of interphase between particle and matrix can improve fracture toughness of polymer particle composite through debonding process. The conclusions of this paper can contribute to a better understanding of the behavior of micro-crack in particulate composites with respect to interphase.

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Majer, Zdeněk, Kateřina Štegnerová, Pavel Hutař, Martin Pletz, Raul Bermejo, and Luboš Náhlík. "Residual Lifetime Determination of Low Temperature Co-Fired Ceramics." Key Engineering Materials 713 (September 2016): 266–69. http://dx.doi.org/10.4028/www.scientific.net/kem.713.266.

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The effect of subcritical crack growth is nowadays intensively studied mainly in relation to the strength of ceramic materials. The main aim of the contribution is to describe behavior of micro-crack propagating in the Low Temperature Co-fired Ceramics (LTCC) under subcritical crack growth (SCCG) conditions. The micro-crack behavior is significantly influenced by residual stresses developed in the LTCC due to different coefficients of thermal expansion of individual components. Two-dimensional numerical model was developed to simulate micro-crack propagation through the composite. The micro-crack propagation direction was determined using Sih’s criterion based on the strain energy density factor and the micro-crack path was obtained. The residual lifetime of the specific ceramic particulate composite (LTCC) was estimated on the basis of experimental data. The paper contributes to a better understanding of micro-crack propagation in particulate ceramic composites in the field of residual stresses.

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Demirel, G., IH Baltacioglu, ME Kolsuz, M. Ocak, B. Bilecenoglu, and K. Orhan. "Volumetric Cuspal Deflection of Premolars Restored With Different Paste-like Bulk-fill Resin Composites Evaluated by Microcomputed Tomography." Operative Dentistry 45, no. 2 (March 1, 2020): 143–50. http://dx.doi.org/10.2341/19-019-l.

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SUMMARY Objectives: The aim of this study was to measure the volumetric cuspal deflection of premolars restored with different paste-like bulk-fill resin composites using microcomputed tomography (micro-CT). Methods and Materials: A total of 35 freshly extracted human maxillary second premolars were selected for this study. Standardized large MOD cavities were prepared in each premolar with a bucco-lingual width of 4 mm and a cavity depth of 4 mm measured from the palatal cusp tip. After cavity preparation, all samples were scanned immediately using a micro-CT system. After the initial micro-CT scanning, restorative procedures were performed. Four groups received different paste-like bulk-fill composites—Beautifil-Bulk Restorative (BBR), Admira Fusion x-tra (AFX), x-tra fill, and Sonic Fill—and the control group received a conventional universal composite and Clearfil Majesty Esthetic (CME). Immediately after the restorative procedure, each tooth was scanned by micro-CT in the same manner as the initial scanning. The buccal and palatal regions of each restoration were evaluated separately in terms of cuspal deflection. One-way analysis of variance was used to compare the effect of the composite resin, and multiple comparisons were performed by the Tukey test with a level of significance of α = 0.05. Results and Discussion: Multiple comparisons showed that teeth restored with the conventional paste-like composite and CME (control) had significantly different cuspal deflection from those filled with paste-like bulk-fill composites (p<0.05). Among the bulk-fill composites, a significant difference was observed between BBR and AFX (p<0.05). Conclusions: Paste-like bulk-fill resin composites had significantly lower cuspal deflection than the conventional paste-like resin composite tested.

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Nayak, Suhas Yeshwant, Srinivas Shenoy Heckadka, Linto George Thomas, and Anil Baby. "Tensile and Flexural Properties of Chopped Strand E-glass Fibre Mat Reinforced CNSL-Epoxy Composites." MATEC Web of Conferences 144 (2018): 02025. http://dx.doi.org/10.1051/matecconf/201814402025.

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Glass fibres have the principal advantages such as high tensile strength, high chemical resistance, low cost, and excellent insulating properties which makes them an important constituent in fibre reinforced plastic and composite industry. In this study, E-glass fibre in the form of Chopped Strand Mat (CSM) with different weight fractions such as 15%, 30%, and 45% were used as reinforcement in CNSL-epoxy resin composites. Fabrication of the composites was done by hand layup technique. Micro-hardness, tensile and flexural properties were investigated for all the composite panels of different compositions. The results clearly indicated an improvement in micro hardness, tensile and flexural properties with the increase in fibre content.

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Bohinc, Klemen, Erna Tintor, Davor Kovačević, Rajko Vidrih, Anamarija Zore, Anže Abram, Željka Kojić, Marija Obradović, Valentina Veselinović, and Olivera Dolić. "Bacterial Adhesion on Glass–Ionomer Cements and Micro/Nano Hybrid Composite Dental Surfaces." Coatings 11, no. 2 (February 16, 2021): 235. http://dx.doi.org/10.3390/coatings11020235.

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Dental restorations need to reproduce the aspect of the natural teeth of the patient, and must be non-toxic, biocompatible, and have good mechanical properties so that they can last for longer. The aim of this study was to determine the extent of bacterial adhesion of Streptococcus mutans on four different dental material surfaces, i.e., two glass–ionomer cements (Fuji conventional and Fuji hybrid) and two ceramic composites (Micro hybrid composite and Nano hybrid composite). To understand the bacterial adhesion on these four different dental materials, various surface properties were measured: roughness, contact angle, CIE color parameters and zeta potential. We found that the greatest adhesion extent was obtained for the Nano hybrid composite surface. The pronounced adhesion is the interplay between the relatively high roughness and hydrophilicity of the Nano hybrid composite surface. Color changes upon immersing ceramic composites in red wine and black tea proved that both beverages adhered to them. Black tea adhered more intensively than wine, and showed a higher inhibitory effect on the growth of Streptococcus mutans and Staphylococcus aureus.

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Journal articles on the topic 'Micro composite'

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