Effect of Al2O3 nanofibers on compaction, phase composition, and mechanical properties of ZrO2-based composites obtained by vacuum pressureless sintering

2021 ◽  
pp. 132-143
Author(s):  
A. A. Leonov ◽  
E. V. Abdulmenova ◽  
M. P. Kalashnikov ◽  
Jing Li
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Crack Resistance ◽  
Physicomechanical Properties ◽  
Relative Content ◽  
Pressureless Sintering ◽  
Vacuum Sintering ◽  
Tetragonal Modification ◽  
Different Content ◽  
Properties Of Composites

This work studies the effect of the relative content of Al2O3 nanofibers on the compaction, phase composition, and physicomechanical properties of composites based on ZrO2 obtained by free vacuum sintering. It was found that in the process of manufacturing composites, nanofibers are sintered into Al2O3 grains of complex, elongated shape, which form a solid, frame-reinforcing structure. The relative density of composites with 5 wt. % and 10 wt. % of nanofibers, decreases up to 95%. It is shown that in all sintered samples the tetragonal modification of ZrO2 acts as the main phase, and the different content of nanofibers affects the amount of cubic and monoclinic modifications of ZrO2. It was found that addition of 5 wt. % and 10 wt. % of Al2O3 nanofibers increases the microhardness of the composite by 11% and crack resistance by 46%.

Production of mullite‒TiC‒с-BN‒с-ZrO2-materials by the method of plasma-spark sintering and their properties

2019 ◽  
pp. 23-29 ◽  
Author(s):  
A. V. Hmelov
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Elastic Modulus ◽  
Linear Correlation ◽  
Modulus Of Elasticity ◽  
Physical And Mechanical Properties ◽  
Linear Shrinkage ◽  
Physicomechanical Properties ◽  
Intensive Development ◽  
Crystalline Microstructure

The effect of different с-BN and с-ZrO2 ratios on the phase composition, microstructure, relative density, open porosity, linear shrinkage, physicomechanical properties, and linear correlation of the elastic modulus and toughness of samples during plasma-spark sintering at pressing load 70 MPa in the range of 1200‒1600 °C is shown. The synthesized powders of TiC, c-BN and c-ZrO2, sintered at 1400 °C by the plasma-spark method, are characterized by intense crystallization of the phases. Sintered samples with different ratios of c-BN and c-ZrO2 show the intensive development of mullite and TiC. An increase in the c-BN / c-ZrO2 ratio promotes an active increase in c-BN and a less intensive increase in с-ZrO2 in the range of 1200‒1600 °C, and it causes the formation of a less uniform and densely sintered crystalline microstructure with a large number of pores at 1500 °C. This sample has lower values of physical and mechanical properties and a lower linear correlation of the modulus of elasticity and toughness in the range of 1200‒1600 °C and lower crack resistance at 1500 °C. Ill. 9. Ref. 13. Tab. 1.

Mechanical Properties of WC-Co Cemented Carbide Prepared via Vacuum Sintering

2013 ◽  
Vol 275-277 ◽  
pp. 1917-1920
Author(s):  
Bing Liang Liang ◽  
Yun Long Ai ◽  
Chang Hong Liu ◽  
Nan Jiang
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Relative Density ◽  
Sintering Temperature ◽  
Rupture Strength ◽  
Cemented Carbide ◽  
Vacuum Sintering ◽  
Transverse Rupture Strength ◽  
Temperature Range ◽  
Peak Value

WC-Co cemented carbide specimens were prepared via vacuum sintering. The influences of composition and sintering temperature on phase composition, microstructure and mechanical properties of WC-Co cemented carbide were investigated. The results show that dense specimens were obtained in the sintering temperature range of 1280~1400°C and the relative density reached over 95%. Only WC and Co3W3C (-phase) were detected by XRD without any else phases, even though Co. With the ascended sintering temperature, hardness increased and the transverse rupture strength (TRS) ascended to peak value and then descended. WC-Co cemented carbide with excellent mechanical properties (HRA>90, TRS~700MPa and KIC>10MPa•m1/2) were obtained.

Properties of Bamboo Fiber Reinforced Cornstarch-Based Composites

2012 ◽  
Vol 200 ◽  
pp. 237-242
Author(s):  
Guang Sheng Zeng ◽  
Rui Zhen Lin ◽  
Cong Meng ◽  
Lei Chen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
High Temperature ◽  
Extrusion Process ◽  
Elongation Rate ◽  
Bamboo Fiber ◽  
Physical Methods ◽  
Plasticizer Content ◽  
Different Content ◽  
Properties Of Composites

In this paper the composites made of cornstarch and PVA as matrix, bamboo fiber as reinforcement, glycerol and urea as mixed plasticizer were prepared through the extrusion molding. By physical methods, the effects of cornstarch, bamboo fiber, PVA and mixed plasticizer on the mechanical properties of composites were investigated. SEM was used to observe the influence of different content of mixed plasticizer in cornstarch. The results showed that an increase in mixed plasticizer content from 10% to 40% in cornstarch did improve the mechanical properties of the composites compared without mixed plasticizer, and when the mixed plasticizer (wt-glycerol: wt-urea=2:1) content was 30% to cornstarch, the composite showed the highest tensile strength and elongation rate. Composites made from 20% of bamboo fiber, 30% of cornstarch, 50% of PVA and 30% of mixed plasticizer to cornstarch gave the best tensile strength (15.8N). Glycerol and urea could permeate the cornstarch molecules and plasticize it under high temperature and shearing in the extrusion process.

scholarly journals Physicomechanical Properties of Epoxyurethane Biocomposites Strengthened with Hemp Wood Core

2021 ◽  
Vol 9 (1) ◽  
pp. 9-18
Author(s):  
Tetian Samoilenko ◽  
Larysa Yashchenko ◽  
Natalia Yarova ◽  
Oleh Babich ◽  
Oleksandr Brovko
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Flexural Strength ◽  
Soybean Oil ◽  
Epoxy Resin ◽  
Physicomechanical Properties ◽  
Polymer Matrices ◽  
Epoxidized Soybean Oil ◽  
Maximum Content ◽  
Properties Of Composites

Hemp wood core (HWC) filled Si-containing epoxyurethane biocomposites, in which diane epoxy resin was replaced with epoxidized soybean oil (ESO), were obtained. It was shown that the tensile strength of ESO-containing polymer was higher, and the flexural strength was lower than those of original polymer. HWC was especially effective strengthening filler for modified epoxyurethanes, because in that case mechanical properties of composites were higher than those of unfilled polymer matrices. Particularly, flexural and tensile strength of unfilled epoxyurethane with maximum content of ESO were 8.1 and 6.8 MPa respectively, while in corresponding composite they reached 17.3 and 15.7 MPa.

scholarly journals Improving the mechanical properties of zirconia in instrument bearings

2020 ◽  
Vol 329 ◽  
pp. 02023
Author(s):  
V. V. Alisin ◽  
B. A. Diethelm ◽  
A. V. Kulebyakin ◽  
V. A. Myzina ◽  
N. Yu. Tabachkova
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Crack Resistance ◽  
High Speed ◽  
Thrust Bearing ◽  
Stabilized Zirconia ◽  
Partially Stabilized Zirconia ◽  
X Ray ◽  
Bearing Materials ◽  
Rotor Bearings

The article presents the issues of replacing leucosapphires in jeweled bearings of the axes of precision instruments with nanostructured crystals of partially stabilized zirconia. The statement is substantiated that doping with rare earth elements provides an improvement in the performance properties of precision instruments by improving the mechanical properties of bearing materials. The efficiency of doping of zirconia crystals with cerium and neodymium oxides is studied. It was found that doped crystals have increased plasticity, which provides an increase in the crack resistance of crystals. Special attention is paid to the issues of increasing the survivability of high-speed rotor bearings by replacing the thrust bearing of leucosapphire with nanostructured crystals of partially stabilized zirconia doped with cerium and neodymium. The efficiency of improving the mechanical properties is confirmed by the X-ray phase analysis of crystals. The phase composition is studied by Raman scattering and the lattice parameters are determined. The increased crack resistance of the thrust bearing is confirmed by tests performed using the kinetic microhardness method.

Effect of Nano-Al2O3 on Mechanical Properties and Microstructure of Al2O3/Si3N4 Compound Ceramics

2010 ◽  
Vol 168-170 ◽  
pp. 1846-1849 ◽  
Author(s):  
Shi Ming Hao ◽  
Hui Fang Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Phase Composition ◽  
Bending Strength ◽  
Nitrogen Atmosphere ◽  
Pressureless Sintering ◽  
X Ray ◽  
Ceramics Matrix

The specimens of Al2O3/Si3N4 compound ceramics which contain 3%, 6%, 9%, 12%, 15%, and 18% nano-Al2O3 additions respectively were obtained by pressureless sintering at 1650 in the nitrogen atmosphere. The bending strength and fracture toughness (KIC) were detected. The microstructure and phase composition of the specimens were analyzed by the means of SEM and X-ray. The results show that Al2O3/Si3N4 compound ceramics can be made only using pressureless sintering. With 9-12% nano-Al2O3addition, the specimens have the top mechanical properties. The bending strength reach 710.86MPa, KIC reach 8.61MPa•M1/2. These excellent properties come from many interwoven nitride distributed uniformly in the Al2O3/Si3N4 compound ceramics matrix, which composed of big and firmly plate-like β- Si3N4, hexagonal Sialon and sheet Si2N2O.

Effect of Modified Diatomite on Crystallinity and Mechanical Properties of Polypropylene

2018 ◽  
Vol 913 ◽  
pp. 551-557 ◽  
Author(s):  
Yu Zhao ◽  
Ming Du ◽  
Ke Xin Zhang ◽  
Liang Gao
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Coupling Agent ◽  
Acid Ester ◽  
Coupling Agents ◽  
Polypropylene Composite ◽  
Polypropylene Composites ◽  
Different Content ◽  
Better Than ◽  
Properties Of Composites

The different coupling agent is used for diatomite modification. The diatomite with different content are melt and mixed with polypropylene to prepare diatomite/polypropylene composites. The modification effects of different coupling agent on diatomite and the influence of agent and diatomite contents on crystallization behavior of polypropylene and mechanical properties of composites are investigated. The results show that different coupling agents have the modification effects on diatomite influence crystallization of polypropylene but the aluminum agent is better than other agents. With the increase of the content of aluminum acid ester coupling agent, the size of bubble pore is uniform, and then the compressive strength reaches to a maximum when aluminum acid ester coupling agent content is 1%. With the increase of the content of diatomite, the porosity of bubble pore of diatomite/polypropylene composite material is gradually increases. The crystallinity of polypropylene and yield strength reach to a maximum (48.15% and 21.5%) when diatomite content is 30%. In addition, the diatomite/polypropylene composites have better compressive strength than the others.

scholarly journals Применение газовой экструзии для синтеза высокопрочного композита на основе алюминиевого сплава серии 5xxx, упрочненного углеродными наноструктурами

2020 ◽  
Vol 46 (5) ◽  
pp. 7
Author(s):  
А.В. Аборкин ◽  
И.В. Сайков ◽  
В.Д. Бербенцев ◽  
А.М. Объедков ◽  
А.Е. Сычев ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Phase Composition ◽  
Comparative Analysis ◽  
Structural Phase ◽  
High Energy ◽  
Hybrid Nanostructures ◽  
Published Data ◽  
Energy Ball ◽  
Properties Of Composites

Composite materials based on aluminum alloy 5xxx series, reinforced by 0.1 wt.% MWCNTs or 0.1 wt.% WC1-x/MWCNTs, were synthesized by high-energy ball milling and subsequent gas extrusion. The structural-phase composition and physical-mechanical properties of bulk composites are characterized. By comparative analysis of the results obtained with published data on the properties of composites based on aluminum alloys 5xxx series shows the prospects for the use of gas extrusion for consolidation, as well as the effectiveness of alloy strengthening by microadditives MWCNT-hybrid nanostructures.

scholarly journals The properties of composites based on NR/CSM rubber blend and waste rubber powder

2018 ◽  
Vol 8 (13) ◽  
Author(s):  
Gordana Marković ◽  
Milena Cincović ◽  
Vojislav Jovanović ◽  
Dejan Kojić ◽  
Nevena Vukić ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Irradiation Dose ◽  
Tensile Modulus ◽  
Elongation At Break ◽  
Waste Rubber ◽  
Elastomeric Materials ◽  
Waste Rubber Powder ◽  
Powder Content ◽  
Different Content ◽  
Properties Of Composites

The use of reclaiming scrap waste rubber is of great ecological interest due to itssignificant influence to the environment. Powdered waste rubber (WRP) can be used asa filler in mixtures with rubbers, thermoplastics, and as modifiers for asphalt. In this workthe composites based on natural rubber (NR) and chlorosufonated polyethylene (CSM)filled with different content of WRP were prepared on a laboratory-size two-roll mixingmill. The curing by sulfur was done at 160º C. The mechanical properties, namely tensilestrength, tensile modulus at 100% elongation, elongation at break and hardness have beenfollowed up as a function of irradiation dose (100; 200; 300; 400 kGy), as well as wasterubber powder content (0; 20; 40; 60; 80; 100 phr). It was assessed that the addition of20 phr waste rubber has improved the properties of obtained elastomeric materials. Theimprovement of composites mechanical properties is in correlation with homogeneousWRP distribution which has been assigned by scanning electron microscopy (SEM).

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