The Effect of Dispersion Method on the Mechanical Properties of Graphene Reinforced Alumina Composites

2018 ◽  
Vol 281 ◽  
pp. 93-98 ◽  
Author(s):  
Lu Wang ◽  
Jian Qiang Bi ◽  
Wei Li Wang ◽  
Xu Xia Hao ◽  
Xi Cheng Gao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Great Influence ◽  
Physical And Mechanical Properties ◽  
Structural Ceramics ◽  
Alumina Matrix ◽  
Dispersion Method ◽  
Mechanical Stirring ◽  
Alumina Composites ◽  
Scanning Electron

Due to the remarkable physical and mechanical properties of graphene, it is considered to be one of the most promising reinforcements for structural ceramics. In this paper, the composite material is compacted by hot pressing and the effects of mechanical stirring and ultrasonic on dispersion of graphene in alumina matrix were investigated, which was believed to have a great influence on the mechanical properties of the hot-pressed composites. It is found that from Scanning electron microscopy (SEM) observation. Compared with ultrasonic, the composite, in which graphene was dispersed by mechanical stirring, showed higher bending strength (555.1MPaVS432.3MPa) and fracture toughness (4.4MPa·m1/2VS 4.1MPa·m1/2). The result is much more promising to be employed in the designing and processing of graphene composites.

Physical and Mechanical Properties of Mullite-Whisker Reinforced Alumina Composites

2007 ◽  
Vol 334-335 ◽  
pp. 325-328 ◽  
Author(s):  
Wei Kong Pang ◽  
Nobuo Tezuka ◽  
It Meng Low ◽  
E.G. Mehrtens ◽  
Bruno A. Latella
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Hot Isostatic Pressing ◽  
Physical And Mechanical Properties ◽  
Reaction Sintering ◽  
Alumina Matrix ◽  
Young’S Moduli ◽  
Solid Density ◽  
Alumina Composites

Reaction sintering and hot-isostatic-pressing (HIP) have been used for the compaction and densification of mullite-whisker-reinforced alumina composites. The effect of alumina matrix constraints on the in-situ transformation sequence in alumina-halloysite-AlF3 system was studied using differential thermal analysis. The physical and mechanical properties of the HIPed samples have been characterized in terms of bulk density, apparent solid density, porosity, Young’s moduli, flexural strength, hardness and the fracture toughness.

Preparation of Pigmented Glass for Infiltration and Investigation of its Physical and Mechanical Properties

2012 ◽  
Vol 512-515 ◽  
pp. 1802-1806
Author(s):  
Huai Xiu Lu ◽  
Yuan Fu Yi ◽  
Bin Deng ◽  
Long Quan Shao ◽  
Li Sheng Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Bending Strength ◽  
Porous Alumina ◽  
Physical And Mechanical Properties ◽  
Alumina Crucible ◽  
Three Point Bending ◽  
Scanning Electron

Aim To explore pigmented glass for infiltration and investigate its physical and mechanical properties. Methods The pigmented glass was prepared by melting glass components in an alumina crucible at 1400°C for 2h. The thermal properties were tested using a Setaram-TGDTA 92 analyzer; three point bending strength and fracture toughness were also tested; the microstructure of the glass was studied using a scanning electron microscope. Results The thermal expansion coefficient over the range 20–600 °C was 6.2 × 10-6 °C -1, Tg was about 690 °C, the density, bending strength, fracture toughness and Vickers hardness were 2.23 g/cm3, 118 MPa, 1.22 MPam1/2, and 7.4 GPa respectively. Conclusion The pigments have no detrimental effects on the physical and mechanical properties; thus the pigmented glass for infiltration has favorable physical and mechanical properties and also good compatibility with presintered porous alumina.

scholarly journals Mechanical properties of titanium carbonitride reinforced alumina tool composites

Mechanik ◽  
2018 ◽  
Vol 91 (5-6) ◽  
pp. 438-442
Author(s):  
Magdalena Szutkowska ◽  
Marek Boniecki ◽  
Marcin Podsiadło ◽  
Andrzej Kalinka
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elevated Temperatures ◽  
Physical And Mechanical Properties ◽  
Young Modulus ◽  
Titanium Carbonitride ◽  
Pressureless Sintering ◽  
Alumina Composites ◽  
Scanning Electron

The present study reports mechanical properties obtained by reinforcing alumina composites with Ti(C,N) in amount 30 wt.% prepared on the basis micro and nanoscale trade powders. The pressureless sintering PS in a vacuum and SPS method of sintering were used. Vickers hardness, density, Young modulus, wear resistance were evaluated. Fracture toughness (KIC) at ambient and elevated temperatures up to 1073 K, characteristic for tool work was measured. Physical and mechanical properties of the composites Al2O3/Ti(C,N)/ZrO2 based on the powders in microscale were compared with composites containing nanoscale powders in a range from 17 to 36 wt.%. Tested composites with nanoscale powders content reveal lower KIC (approx. 10÷30%) at ambient temperature in comparison to composites based on powders in microscale. However, in the elevated temperatures their fracture toughness increases up to 30%. The observation of the microstructure of tested composites was carried out using scanning electron microscopy.

Structure and properties of compact articles from high-alloyed iron powder with adding of boron nitride

2020 ◽  
pp. 39-48
Author(s):  
B. O. Bolshakov ◽  
◽  
R. F. Galiakbarov ◽  
A. M. Smyslov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Grain Boundary ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Operating Conditions ◽  
Structure And Properties ◽  
Steam Turbines ◽  
Friction Forces ◽  
Wide Range

The results of the research of structure and properties of a composite compact from 13 Cr – 2 Мо and BN powders depending on the concentration of boron nitride are provided. It is shown that adding boron nitride in an amount of more than 2% by weight of the charge mixture leads to the formation of extended grain boundary porosity and finely dispersed BN layers in the structure, which provides a high level of wearing properties of the material. The effect of boron nitride concentration on physical and mechanical properties is determined. It was found that the introduction of a small amount of BN (up to 2 % by weight) into the compacts leads to an increase in plasticity, bending strength, and toughness by reducing the friction forces between the metal powder particles during pressing and a more complete grain boundary diffusion process during sintering. The formation of a regulated structure-phase composition of powder compacts of 13 Cr – 2 Mо – BN when the content of boron nitride changes in them allows us to provide the specified physical and mechanical properties in a wide range. The obtained results of studies of the physical and mechanical characteristics of the developed material allow us to reasonably choose the necessary composition of the powder compact for sealing structures of the flow part of steam turbines, depending on their operating conditions.

scholarly journals Eco-Friendly, High-Density Fiberboards Bonded with Urea-Formaldehyde and Ammonium Lignosulfonate

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 220
Author(s):  
Petar Antov ◽  
Viktor Savov ◽  
Ľuboš Krišťák ◽  
Roman Réh ◽  
George I. Mantanis
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
High Density ◽  
Thickness Swelling ◽  
Formaldehyde Content ◽  
Uf Resin ◽  
Natural Wood ◽  
European Standards

The potential of producing eco-friendly, formaldehyde-free, high-density fiberboard (HDF) panels from hardwood fibers bonded with urea-formaldehyde (UF) resin and a novel ammonium lignosulfonate (ALS) is investigated in this paper. HDF panels were fabricated in the laboratory by applying a very low UF gluing factor (3%) and ALS content varying from 6% to 10% (based on the dry fibers). The physical and mechanical properties of the fiberboards, such as water absorption (WA), thickness swelling (TS), modulus of elasticity (MOE), bending strength (MOR), internal bond strength (IB), as well as formaldehyde content, were determined in accordance with the corresponding European standards. Overall, the HDF panels exhibited very satisfactory physical and mechanical properties, fully complying with the standard requirements of HDF for use in load-bearing applications in humid conditions. Markedly, the formaldehyde content of the laboratory fabricated panels was extremely low, ranging between 0.7–1.0 mg/100 g, which is, in fact, equivalent to the formaldehyde release of natural wood.

scholarly journals Selected physical and mechanical properties of Scots pine (Pinus sylvestris L.) wood from stands of younger age classes as criteria for rational utilization of timber

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Przemysław Marcin Pikiński ◽  
Jaroslav Szaban ◽  
Gerda Šilingienė ◽  
Robert Korzeniewicz ◽  
Witold Pazdrowski
Keyword(s):  
Mechanical Properties ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Growth Conditions ◽  
Tree Age ◽  
Coniferous Forests ◽  
Forest Site ◽  
Quality Coefficient

The aim of this study was to assess the quality of Scots pine (Pinus sylvestris L.) wood depending on the age of trees, forest site conditions and social class of tree position in the stand. Analyses were based on the determination of specific density and static bending strength, as well as the strength quality coefficient. It was to determine changes in physical and mechanical properties of timber depending on tree age as well as growth conditions reflected in the forest site such as fresh mixed coniferous forests and fresh mixed broadleaved forests. Experimental plots were established in 6 localities with 30, 40 and 60-year-old trees. In each of the stands, a 1-hectare experimental plot was established. Based on the measured DBH and tree height, dimensions of three mean sample trees were calculated, while the classification of social class of tree position in the stand developed by Kraft (1884) was also applied. Analyses were conducted on wood samples with 12% moisture content. Strength tests on wood samples were performed on an Instron 33RH204 universal strength testing machine. A detailed analysis showed properties of pine wood are improved with an increase of tree age in both forest sites. Statistically significant differences were observed for wood density and static bending strength. More advantageous properties were observed for wood of pines from the less fertile forest site, i.e., fresh mixed coniferous forests. Density and static bending strength were markedly determined by tree age and growth conditions. The static bending strength quality coefficient from pines growing in the fresh mixed coniferous forests increased between 30 and 40 years, similarly as it was for the fresh mixed broadleaved forests, while between 40 and 60 years, it deteriorated for the fresh mixed coniferous forests. Wood density from the fresh mixed coniferous forests was by 3% to 7% greater than pines growing in fresh mixed broadleaved forests. In turn, static bending strength of wood from pines growing in fresh mixed coniferous forests was by 4% to 10% greater than trees from the fresh mixed broadleaved forests.  Keywords: Scots pine, wood properties, forest site, Poland

Mechanical properties and freeze-thaw resistances of bronze-concrete composites

2021 ◽  
Vol 12 (2) ◽  
pp. 39
Author(s):  
Tuba Bahtli ◽  
Nesibe Sevde Ozbay
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Test Methods ◽  
Pulse Velocity ◽  
Plastic Energy ◽  
Freeze Thaw ◽  
Schmidt Rebound Hammer

Studies in the literature show that the physical and mechanical properties of concrete could be improved by the incorporation of different kinds of industrial waste, including waste tire rubber and tire steel. Recycling of waste is important for economic gain and to curb environmental problems. In this study, finely ground CuAl10Ni bronze is used to improve the physical and mechanical properties, and freeze-thaw resistances of C30 concrete. The density, cold crushing strength, 3-point bending strength, elastic modulus, toughness, and freeze-thaw resistances of concrete are determined. In addition, the Schmidt Rebound Hammer (SRH) and the ultrasonic pulse velocity (UPV) tests, which are non-destructive test methods, are applied. SEM/EDX analyses are also carried out. It is noted that a more compacted structure of concrete is achieved with the addition of bronze sawdust. Then higher density and strength values are obtained for concretes that are produced by bronze addition. In addition, concretes including bronze sawdust generally show higher toughness due to high plastic energy capacities than pure concrete.

An attempt to use „Tetra Pak” waste material in particleboard technology

2021 ◽  
Vol 114 ◽  
pp. 70-75
Author(s):  
Radosław Auriga ◽  
Piotr Borysiuk ◽  
Alicja Auriga
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Core Layer ◽  
Waste Material ◽  
Thickness Swelling ◽  
The Core ◽  
Tetra Pak ◽  
The Impact

An attempt to use „Tetra Pak” waste material in particleboard technology. The study investigates the effect of addition Tetra Pak waste material in the core layer on physical and mechanical properties of chipboard. Three-layer chipboards with a thickness of 16 mm and a density of 650 kg / m3 were manufactured. The share of Tetra Pak waste material in the boards was varied: 0%, 5%, 10% and 25%. The density profile was measured to determine the impact of Tetra Pak share on the density distribution. In addition, the manufactured boards were tested for strength (MOR, MOE, IB), thickness swelling and water absorption after immersion in water for 2 and 24 hours. The tests revealed that Tetra Pak share does not affect significantly the value of static bending strength and modulus of elasticity of the chipboard, but it significantly decreases IB. Also, it has been found that Tetra Pak insignificantly decreases the value of swelling and water absorption of the chipboards.

scholarly journals The Impact of Paraffin-Thermal Modification of Beech Wood on Its Biological, Physical and Mechanical Properties

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1102 ◽  
Author(s):  
Ladislav Reinprecht ◽  
Miroslav Repák
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Beech Wood ◽  
Physical And Mechanical Properties ◽  
Brown Rot ◽  
European Beech ◽  
White Rot ◽  
White Rot Fungus ◽  
Poria Placenta ◽  
The Impact

The European beech (Fagus sylvatica L.) wood was thermally modified in the presence of paraffin at the temperatures of 190 or 210 °C for 1, 2, 3 or 4 h. A significant increase in its resistance to the brown-rot fungus Poria placenta (by 71.4%–98.4%) and the white-rot fungus Trametes versicolor (by 50.1%–99.5%) was observed as a result of all modification modes. However, an increase in the resistance of beech wood surfaces to the mold Aspergillus niger was achieved only under more severe modification regimes taking 4 h at 190 or 210 °C. Water resistance of paraffin-thermally modified beech wood improved—soaking reduced by 30.2%–35.8% and volume swelling by 26.8%–62.9% after 336 h of exposure in water. On the contrary, its mechanical properties worsened—impact bending strength decreased by 17.8%–48.3% and Brinell hardness by 2.4%–63.9%.

scholarly journals Relationships between Thermoplastic Type and Properties of Polymer-Triticale Boards

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1750 ◽  
Author(s):  
Radosław Mirski ◽  
Pavlo Bekhta ◽  
Dorota Dziurka
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Thickness Swelling ◽  
Hydrophobic Properties ◽  
Pine Wood ◽  
Moisture Contents ◽  
The Face

This study examined the effects of selected types of thermoplastics on the physical and mechanical properties of polymer-triticale boards. The investigated thermoplastics differed in their type (polypropylene (PP), polyethylene (PE), polystyrene (PS)), form (granulate, agglomerate) and origin (native, recycled). The resulting five-ply boards contained layers made from different materials (straw or pine wood) and featured different moisture contents (2%, 25%, and 7% for the face, middle, and core layers, respectively). Thermoplastics were added only to two external layers, where they substituted 30% of straw particles. This study demonstrated that, irrespective of their type, thermoplastics added to the face layers most favorably reduced the hydrophobic properties of the boards, i.e., thickness, swelling, and V100, by nearly 20%. The bending strength and modulus of elasticity were about 10% lower in the experimental boards than in the reference ones, but still within the limits set out in standard for P7 boards (20 N/mm2 according to EN 312).

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