scholarly journals Effects of TiO2 Nanoparticle Addition on Microstructure and Selected Properties of Ag–xTiO2 Composites

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4846
Author(s):  
Anna Wąsik ◽  
Beata Leszczyńska-Madej ◽  
Marcin Madej
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Nitrogen Atmosphere ◽  
Contact Boundary ◽  
Powder Metallurgy Method ◽  
Tem Analysis ◽  
Single Action ◽  
Steel Balls ◽  
Positive Effect ◽  
Made In

The paper presents the results of a study of the microstructure and selected properties of silver-based composites reinforced with TiO2 nanoparticles, produced by the powder metallurgy method. Pure silver powders were mixed with TiO2 reinforcement (5 and 10 wt%) and 5 mm steel balls (100Cr6) for 270 min in a Turbula T2F mixer to produce a homogeneous mixture. The composites were made in a rigid die with a single-action compaction press under a pressure of 400 MPa and 500 MPa and then sintered under nitrogen atmosphere at 900 °C. Additionally, to improve the density and mechanical properties of the obtained sinters, double pressing and double sintering operations were conducted. As a result, compacts with a density of 90–94% were obtained. The microstructure of the sintered compacts consists of uniform grains, and the TiO2 reinforcement phase particles are located on the grain boundaries. There were no discontinuities at the Ag–TiO2 contact boundary, which was confirmed by SEM and TEM analysis. The use of a higher pressure had a positive effect on the hardness and flexural strength of the tested materials. It was found that the composites with 5 wt% TiO2 pressed under 500 MPa are characterized by the highest level of mechanical properties. The hardness of these composites is 57 HB, while the flexural strength is 163 MPa.

scholarly journals Mechanical Properties of Cement-Treated Soil Mixed with Cellulose Nanofibre

2021 ◽  
Vol 11 (14) ◽  
pp. 6425
Author(s):  
Hidenori Takahashi ◽  
Shinya Omori ◽  
Hideyuki Asada ◽  
Hirofumi Fukawa ◽  
Yusuke Gotoh ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Geotechnical Engineering ◽  
Strength Development ◽  
Soft Ground ◽  
Wood Cellulose ◽  
Treated Soil ◽  
Made In ◽  
Cement Treatment

Cellulose nanofibre (CNF), a material composed of ultrafine fibres of wood cellulose fibrillated to nano-order level, is expected to be widely used because of its excellent properties. However, in the field of geotechnical engineering, almost no progress has been made in the development of techniques for using CNFs. The authors have focused on the use of CNF as an additive in cement treatment for soft ground, where cement is added to solidify the ground, because CNF can reduce the problems associated with cement-treated soil. This paper presents the results of a study on the method of mixing CNF, the strength and its variation obtained by adding CNF, and the change in permeability. CNF had the effect of mixing the cement evenly and reducing the variation in the strength of the treated soil. The CNF mixture increased the strength at the initial age but reduced the strength development in the long term. The addition of CNF also increased the flexural strength, although it hardly changed the permeability.

scholarly journals Performance of Isolated Footings Reinforced Randomly by Glass Fiber

2019 ◽  
pp. 1-8
Author(s):  
Elsayed El Kasaby ◽  
Mohammad Farouk A. Bdelmagied
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Fatigue Properties ◽  
Structural Elements ◽  
Fiber Glass ◽  
Forming Process ◽  
Rectangular Shape ◽  
Concrete Crack ◽  
Reinforced Steel ◽  
Positive Effect

Fiber glass reinforced concrete (FGRC) is used form any structural elements due to its high mechanical properties, particularly flexural strength. As the concrete crack forming process accelerates and the probability of sudden fractures increases. There were various methods to eliminate this weakness of concrete. One of most common methods was employed of randomly distributed fiber. In this paper, two types of isolated footings were utilized, square and rectangular shape reinforced by a fiber glass with a length of 18 mm and having a rate of (0.20, 0.30, 0.35, 0.40, 0.50 and 1.00%) of weight, to experimentally investigate the tensile and fatigue properties of footings The results of FGRC were compared with the reinforced steel concrete. The results revealed that FGRC has a positive effect on the tensile and fatigue properties of isolated footing, especially with higher percentage of used fiber glass.

Effect of Carbon Nanotubes on Mechanical Properties of Cement Composites

2014 ◽  
Vol 915-916 ◽  
pp. 768-771
Author(s):  
Yun Feng Li ◽  
Jing Zhou ◽  
Lei Wen Gao
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Brittle Failure ◽  
Cement Composites ◽  
Toughness Index ◽  
Different Content ◽  
Positive Effect

Nanotubes exhibiting great mechanical properties are expected to produce significantly stronger and tougher cement composites. The effects of Carbon Nanotubes to cement based composites are investigated in this paper. The flexural strength and the compressive strength of the CNTs cement composites under different content of are tested and the toughness indexes are analyzed. The results show that CNTs have a positive effect on the brittle failure of cement composites, and that the compressive strength and flexural strength of 0.10% CNTs cement composites are significantly increased. The toughness index of 0.05% CNTs cement composites is relatively higher.

The effect of Cu addition on wear mechanisms and tribological properties of aluminium matrix composites reinforced with SiC

2019 ◽  
Vol 53 (22) ◽  
pp. 3073-3083
Author(s):  
Beata Leszczyńska-Madej ◽  
Marcin Madej ◽  
Anna Wąsik
Keyword(s):  
Friction Coefficient ◽  
Tribological Properties ◽  
Nitrogen Atmosphere ◽  
Aluminium Matrix ◽  
Matrix Composites ◽  
Friction Process ◽  
Single Action ◽  
Positive Effect ◽  
Carbide Content

The article discusses the results of research on the effect of 4 wt.% Cu addition on the tribological properties of composites based on aluminium matrix reinforced with SiC particles. The research also included the analysis of the microstructure and the hardness. The composites were made of elementary powders in a rigid die on a single-action compaction press and then sintered under the nitrogen atmosphere. The silicon carbide content was: 2.5; 5; 7.5; 10 and 15 wt.%. The tests of tribological properties were carried out using a block-on-ring T05 tester under the technically dry friction conditions, and the counter-sample was made of 100 Cr6 steel. The research covered the determination of mass losses, coefficients of friction as well as friction coefficient changes as the function of process duration and material. The obtained results proved that the addition of 4 wt.% Cu helps to reduce the friction coefficient and for composites that contain above 7.5 wt.% SiC also improves their wear resistance. It was also demonstrated that both the addition of Cu as well as an increase of SiC content in the composites have a positive effect on friction by reducing the adhesive wear share in the friction process.

scholarly journals Influence of Microfibers Additive on the Self-healing Performance of Mass Concrete

2021 ◽  
Vol 39 (1A) ◽  
pp. 104-115
Author(s):  
Alaa Z. Dahesh ◽  
Farhad M. Othman ◽  
Alaa A. Abdul-hamead
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Physical And Mechanical Properties ◽  
Sem Analysis ◽  
Mass Concrete ◽  
Self Healing ◽  
Mixture Ratio ◽  
Concrete Mixtures ◽  
Strength Tests ◽  
Positive Effect

Because cracks are the main problem of mass concrete, this paper investigates an experimental study on the effect of polypropylene microfiber (PPMFs) on self -repair behavior of mass concrete, through study the microstructure, workability, physical, and mechanical properties of mass concrete. PPMFs with a diameter of 18 µm add in different percentages (0, 0.5, 1 and 1.5) % of cement weight. Where the prepared mixture ratio was (1:2:4.8) and the water-cement ratio (W/C) was 0.4. Also, 0.6% of Superplasticizer (SP) % of cement weight to all concrete mixtures was added. In this study, an SEM analysis used to observe the effect of PPMFs on the microstructure of mass concrete, and compressive and flexural strength tests for study the mechanical properties of this. And referring to the analysis and discussion of the results, PPMFs used have changed the microstructure of mass concrete, and have an effective effect on improving compressive strength and flexural strength, and mechanism of sealing the cracks of concrete autogenously. Also, 1% PPMFs (% of cement weight) recorded as the highest addition, which has a positive effect on mass concrete properties to apply it in the construction field.

Fabrication and Microstructure of Clay-Based Geopolymer Ceramic Using Powder Metallurgy Method

2015 ◽  
Vol 754-755 ◽  
pp. 145-151 ◽  
Author(s):  
Nur Ain Jaya ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Che Mohd Ruzaidi Ghazali ◽  
Mohammed Binhussain ◽  
Kamarudin Hussin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Flexural Strength ◽  
Pore Structure ◽  
Glassy Phase ◽  
Total Porosity ◽  
Sintered Sample ◽  
Sem Analysis ◽  
Effect Of Temperature ◽  
Powder Metallurgy Method

Geopolymers can be transforms into ceramics upon sintering. This paper reports the effect of temperature on the mechanical properties and microstructure of Na based kaolin geopolymer ceramic. The Na2O.Al2O3.4SiO2was fabricated through powder metallurgy method. The geopolymers samples were exposed to temperature from 900 °C up to 1200 °C. The relative density, total porosity and flexural strength of sintered sample ranged approximately 84%-95%, 5.04%-15.73% and 20-70 MPa respectively. SEM analysis on as-sintered sample showed glassy phase while polished sample showed the pore structure and distribution. XRD results showed that nepheline appeared in all heated samples. Samples heated to 1200 °C achieved highest flexural strength and toughness of 70MPa due to the optimum density.

Slip Degassing to Improve the Properties of Slip Cast and Reaction Bonded Si3N4

2017 ◽  
Vol 751 ◽  
pp. 358-362
Author(s):  
Kritkaew Somton ◽  
Mana Rodchom ◽  
Thassanee Wonglom ◽  
Kannigar Dateraksa ◽  
Ryan C. McCuiston
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Nitrogen Atmosphere ◽  
Phase Content ◽  
Phase Growth ◽  
Hydrogen Bubbles ◽  
Slip Cast ◽  
Xrd Patterns ◽  
Microstructural Examination ◽  
Phase Differences

The effect of slip degassing on the microstructure and mechanical properties of slip cast and reaction bonded Si3N4 was studied. The slip was prepared by aqueous ball milling of silicon (Si) powder. Hydrogen bubbles, a result of Si oxidation during milling, were degassed from the slip using a combination of vacuum and heat. The slip was then cast into a plaster mould to obtain rectangular green bodies. The Si green samples were sintered in a nitrogen atmosphere at 1500°C to convert the Si to Si3N4. After that the nitrided samples were polished to dimensions of 3 x 4 x 30 mm. The density, porosity, flexural strength, phase content and microstructure of the sintered samples were studied. The results showed that the degassing process increased the slip density. After casting and subsequent nitridation, it was found that the average apparent density of the samples increased from 2.89 to 2.95 g/cm3, the porosity decreased from 52.9 to 49.5 %, and the flexural strength increased from 8.1 to 9.3 MPa, when the degassed slip was used. A microstructural examination showed that the pores in the samples were filled with whiskers, which most likely resulted from a vapor phase growth mechanism. The samples produced from the degassed slip tended to have fewer whiskers, due to the reduced pore size and volume. A comparison of the XRD patterns showed no phase differences between the samples. The appearance of Si2N2O, and SiC likely resulted from the reactions between O2 and C impurities with Si3N4.

scholarly journals Mechanical properties of an experimental resin based composite containing silver nanoparticles and bioactive glass

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Amjad Hanif ◽  
Fazal Ghani
Keyword(s):  
Mechanical Properties ◽  
Silver Nanoparticles ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Bioactive Glass ◽  
Vickers Hardness ◽  
Control Group ◽  
The Difference ◽  
Hardness Values ◽  
Made In

Objective: To compare the elastic modulus, flexural strength, and hardness of an experimental resin based composite (RBC) with and without containing silver nanoparticles (AgNPs) and bioactive glass (BAG) with a commercially available RBC. Methods: This study was conducted, during the period August 2016-May 2018, at the Department of Dental Materials, Peshawar Dental College, Peshawar (Pakistan) and Department of Chemistry, University of Montreal, Canada. Test specimens made in the commercial RBC acted as Group-1 (G1). An experimental RBC containing 70 wt % filler content was synthesized. It was first used as such to prepare test specimens to act as the experimental control group (G2). This RBC was then modified by adding various amounts of BAG (5%, 10% and 15%) and a fixed amount of 0.009% AgNPs to use the so modified RBCs for preparing the test specimens to belong to three groups (G3, G4 & G5). The AgNPs had been synthesized in situ by reduction of salt during photo-polymerization. Flexural strength (FS), elastic modulus (EM) and Vickers hardness were determined using universal testing machine and hardness tester respectively. Data were analyzed using one-way ANOVA and Tukey post-hoc test. Results: Except for G3 restorations showing significantly lower mean FS value, the FS for those in the other groups were not significantly different (p>0.05). Elastic modulus of the experimental RBC restorations was though higher than those of the others but the difference was statistically insignificant (p>0.05). Reduced Vickers hardness values were documented for the restorations in the G4 and G5 compared to those in the G3 but again the difference was insignificant (p>0.05). Flexural strength and hardness values of the test specimens in the experimental RBCs were significantly lower than those made in the commercial hybrid RBC (p<0.05). Conclusion: BAG and AgNPs addition to the experimental RBC in the mentioned concentration adversely affected the tested mechanical properties. doi: https://doi.org/10.12669/pjms.36.4.1913 How to cite this:Hanif A, Ghani F. Mechanical properties of an experimental resin based composite containing silver nanoparticles and bioactive glass. Pak J Med Sci. 2020;36(4):---------. doi: https://doi.org/10.12669/pjms.36.4.1913 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Effects of Rare-Earth Oxides Doping on Microstructures and Properties of Al2O3/TiAl Composites

2011 ◽  
Vol 675-677 ◽  
pp. 143-146
Author(s):  
Fen Wang ◽  
Xiao Feng Wang ◽  
Jian Feng Zhu ◽  
Liu Yi Xiang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Rare Earth ◽  
Flexural Strength ◽  
Rare Earth Oxide ◽  
Rare Earth Oxides ◽  
Oxide Content ◽  
The Matrix ◽  
Al2o3 Particles ◽  
Positive Effect

Effects of rare-earth oxides addition (0.38~1.52 mol% of Sm2O3, Eu2O3 and Er2O3) on the property and microstructure of the hot-pressed (1300°C, 2h, 35 MPa) Al2O3 (12 wt %)/TiAl insitu composites have been investigated. The results show that the doping of rare-earth oxides has a positive effect on both mechanical properties and densities of Al2O3/TiAl composites. Densities enhanced with increasing of rare-earth oxides. The flexural strength and fracture toughness were higher than other samples when the rare-earth oxide content was 0.38 mol %. The matrix grains and Al2O3 particles were significantly refined, and Al2O3 particles evenly distributed in the matrix.

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