scholarly journals The sintering kinetics of shellfish porcelain reinforced by sepiolite nanofibres

2018 ◽  
Vol 5 (10) ◽  
pp. 180483 ◽  
Author(s):  
Li Tian ◽  
Lijuan Wang ◽  
Kailei Wang ◽  
Yuedan Zhang ◽  
Jinsheng Liang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Diffusion Mechanism ◽  
Linear Shrinkage ◽  
Liquid Phase Sintering ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Fibre Pullout ◽  
Sintering Behaviour

The work investigated the effect of sepiolite nanofibres on mechanical properties and sintering behaviour of shellfish porcelain. Samples of shellfish porcelain reinforced by sepiolite nanofibres were fired in an electric furnace at 1150, 1200 and 1250°C for a period of 80, 100, 120 and 140 min. Sintered samples were characterized by flexural strength, fracture toughness, scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The results showed that 2 wt% sepiolite nanofibres could increase the flexural strength and fracture toughness of the porcelain bodies through the fibre pullout and the weak interface mechanisms. Sintering activation energies were determined according to the linear shrinkage results. It is found that the liquid-phase sintering mechanism of shellfish porcelain with sepiolite nanofibres is a diffusion mechanism. Porcelain without sepiolite is controlled by volume diffusion, and eventually, the grain boundary diffusion began to appear with the increase of sepiolite addition.

Effects of Co content in TiO2–Co composite prepared by alloying–recomposition–oxidation–sintering process on its mechanical properties and microstructure

2019 ◽  
Vol 53 (24) ◽  
pp. 3483-3495
Author(s):  
Seungkyun Yim ◽  
Ilsong Park ◽  
Jeshin Park
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Diffraction Field ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Transmission Electron ◽  
Content Range ◽  
Structural Characterizations

TiO2–Co composite powders with various Co contents were prepared by the alloying-recomposition-oxidation-sintering process. For comparison, conventionally mixed TiO2–Co composites with the same compositions were sintered at 1000, 1100, 1200, 1300, and 1400℃. Structural characterizations were performed using X-ray diffraction, field-emission scanning electron microscopy, energy-dispersive spectroscopy, and transmission electron microscopy. All of the sintered samples were more densified. A melted matrix was observed at a temperature higher than 1300℃. The flexural strength and the fracture toughness of the TCA sample were higher than those of the conventionally mixed TiO2–Co sample at the same sintering temperature, while the Vickers hardness exhibited the opposite relationship. The flexural strength and the fracture toughness of the TCA sample increased until a Co content of 14 vol%, followed by decrease at 18 vol%, while those of the conventionally mixed TiO2–Co sample increased in the entire Co content range. The highest flexural strength and fracture toughness were observed for T14CA sintered at 1400℃ (161.3 MPa and 6.39 MPa m−1/2, respectively). Consequently, the desirable Co content in the TiO2–Co composite prepared by the alloying–recomposition–oxidation–sintering process was 14 vol%.

Organoclay-reinforced polyethersulfone-modified epoxy-based hybrid nanocomposites

2011 ◽  
Vol 23 (7) ◽  
pp. 526-534 ◽  
Author(s):  
Yang Wang ◽  
Boming Zhang ◽  
Jinrui Ye
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Electron Microscope ◽  
Optical Microscope ◽  
Mechanical Analysis ◽  
Hybrid Nanocomposites ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Modified Epoxy ◽  
Scanning Electron

Hybrid nanocomposites were successfully prepared by the incorporation of polyethersulfone (PES) and organoclay into epoxy resin. They had higher fracture toughness than the prepared PES/epoxy blend and organoclay/epoxy nanocomposites. The microstructures of the hybrid nanocomposites were studied. They were comprised of homogeneous PES/epoxy semi-interpenetrating network (semi-IPN) matrices and organoclay micro-agglomerates made up of tactoid-like regions composed of ordered exfoliated organoclay with various orientations. The former was confirmed with dynamic mechanical analysis, scanning electron microscopy and transmission electron microscopy, while the latter was successfully observed with X-ray diffraction measurements, optical microscope, scanning electron microscope and transmission electron microscope. The improvement of their fracture toughness was due to the synergistic toughening effect of the PES and the organoclay and related to their microstructures.

Effect of Sintering Temperature on Microstructure and Mechanical Properties of Al2O3-TiC-ZrO2 Ceramic Composites

2012 ◽  
Vol 476-478 ◽  
pp. 1031-1035
Author(s):  
Wei Min Liu ◽  
Xing Ai ◽  
Jun Zhao ◽  
Yong Hui Zhou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Temperature ◽  
Ceramic Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Al2O3-TiC-ZrO2ceramic composites (ATZ) were fabricated by hot-pressed sintering. The phases and microstructure of the composites were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The relative density and mechanical properties (flexural strength, fracture toughness and Vicker’s hardness) of the composites were tested. The results show that the microstructure of the composites was the gray core-white rim. With the increase of sintering temperature, the relative density and mechanical properties of the composites increased first and then decreased. The composite sintered at 1705°C has the highest synthetical properties, and its relative density, flexural strength, fracture toughness and Vickers hardness are 98.3%,970MPa,6.0 MPa•m1/2and 20.5GPa, respectively.

Synthesis and Densification of Nanometric Ce0.8Sm0.2O1.9-δ

2006 ◽  
Vol 972 ◽  
Author(s):  
Vincenzo Esposito ◽  
Marco Fronzi ◽  
Enrico Traversa
Keyword(s):  
Electron Microscopy ◽  
Liquid Phase ◽  
Electrochemical Impedance ◽  
Liquid Phase Sintering ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Conventional Sintering ◽  
Eis Measurements ◽  
Co Precipitation

AbstractNanometric 20% molar Sm-doped ceria (SDC20) powders were synthesized by tetrametylethylen ammine (TMDA) co-precipitation method. SDC20 was sintered in several conditions to control the final microstructure. Fast firing and conventional sintering were performed. LiNO3was used as an additive to promote liquid phase sintering of ceria at low temperatures (900-1200°C). Powders and dense pellets were analysed using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). Electrochemical impedance spectroscopy (EIS) measurements were performed on dense pellets in air to estimate the contribution of grain boundary and bulk to the electrical conductivity. Liquid phase sintering produced the densest samples with the highest conductivity.

Flexural Strength of Superfine Grained Si2N2O-Si3N4 Composites

2007 ◽  
Vol 353-358 ◽  
pp. 1477-1480
Author(s):  
Jun Ting Luo ◽  
Qing Zhang ◽  
Kai Feng Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Flexural Strength ◽  
Liquid Phase Sintering ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value ◽  
Average Grain Size ◽  
Main Fracture ◽  
Scanning Electron

The Si3N4- Si2N2O composites were fabricated with amorphous nano-sized silicon nitride powders by the liquid phase sintering(LPS) method. The sintering temperatures ranged from 1500°C to 1700°C. Microstructure and component of the composites were performed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Results show that sintered body consists of Si2N2O and β-Si3N4, with an average grain size about 1μm. The maximum value of flexural strength of the material is 680MPa when sintered at 1700°C. Transcrystalline cracking is the main fracture mechanism of the composites.

Investigation of interfacial phenomena in Ag–Si multilayers during the annealing process

1999 ◽  
Vol 14 (7) ◽  
pp. 2888-2892 ◽  
Author(s):  
J. H. Zhao ◽  
M. Zhang ◽  
R. P. Liu ◽  
X. Y. Zhang ◽  
L. M. Cao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Diffusion Mechanism ◽  
Effective Diffusion ◽  
Annealing Process ◽  
Interfacial Phenomena ◽  
Silver Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

Interfacial phenomena and microstructure in Ag–Si multilayers with a modulation period of 7.64 nm during annealing from 323 to 573 K were investigated by in situ x-ray diffraction and high-resolution transmission electron microscopy. Uphill and downhill diffusion were observed on annealing. The temperature dependence of the effective diffusion coefficient from 373 K (as to downhill diffusion regime) to 523 K was De = 2.02 × 10−20 exp(−0.24 eV/kBT) m2/s. Diffusion of silicon atoms along silver grain boundaries was proposed as the main diffusion mechanism. After annealing, continuous silver sublayers changed to nanometer-sized silver particles (about 4.5 nm) coated completely by amorphous silicon.

Influence of Titanium Sol on the Sintering Behaviour, Microstructure and Properties of Al2O3-SiO2 Ceramic Cores

2013 ◽  
Vol 745-746 ◽  
pp. 507-511
Author(s):  
Jun Chen ◽  
Yue Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Flexural Strength ◽  
Room Temperature ◽  
Formation Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mullite Phase ◽  
Sintering Behaviour ◽  
Scanning Electron

A series of Al2O3-SiO2 ceramic cores with titanium sol sintered at 1350, 1450, 1500 and 1550for 2h, respectively, were prepared, and the phase and microstructure were characterized by X-ray Diffraction and Scanning Electron Microscopy. The influence of titanium sol on the phase transformation, shrinkage rate and flexural strength at room temperature has been investigated. The mullite phase formation temperature decreased by at least 150with the addition of 1wt% to 5wt% TiO2. Additionally, the titania additive promoted the combination of Al2O3 and SiO2, producing mullite phase which reduced the shrinkage and improved the flexural strength.

Pressureless Sintering and Characterization of Al2O3-SiO2-ZrO2 Composite

2012 ◽  
Vol 329 ◽  
pp. 113-128 ◽  
Author(s):  
G. Mebrahitom Asmelash ◽  
Othman Mamat
Keyword(s):  
Fracture Toughness ◽  
Flexural Strength ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
Pressureless Sintering ◽  
Oxide Ceramic ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
X Ray Diffraction ◽  
X Ray

An Oxide Ceramic-Based Composite in the Al2o3-Sio2-Zro2(ASZ) System Was Developed and Investigated Using a Pressureless Sintering Route. the Effect of the Content of each Component and Sintering Temperature upon the Microstructure, Density, Hardness and Strength Was Studied. X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) Were Used to Investigate the Phase Transformation Sequences of the ASZ Composite System. the Flexural Strength Was Measured Using Three-Point Bending Method on a Universal Testing Machine, while the Indentation Fracture (IF) Method Was Used to Determine the Fracture Toughness of the Composite. the Results Showed that, with Varying Zro2Content, Keeping the Silica Content Constant and the Alumina as a Matrix, Densification Tends to Decrease as the Content of Zirconia Increases from 20 Wt. % of the Composition. X-Ray Diffraction Peaks Indicated Fully Developed Alumina, Mullite and Zirconia Phases due to Solid-Phase Reaction and Liquid-Phase Sintering of the System. the Experimental Results Also Revealed that, for a Sintering Temperature of 1500°C, the Hardness Value Ranged from 12 Gpa to 14 Gpa and the Flexural Strength Was 420±31MPa.The Fracture Toughness (KIc) Was Also Reported to Be between 4.5 and 5.1 Mpa.m1/2, for Samples Sintered at a Temperature of 14500C.

Experimental investigation of mechanical and erosion behavior of eggshell nanoparticulate epoxy biocomposite

2020 ◽  
pp. 096739112094345 ◽  
Author(s):  
Manoj Panchal ◽  
G Raghavendra ◽  
A Rahul Reddy ◽  
M Omprakash ◽  
S Ojha
Keyword(s):  
Electron Microscopy ◽  
Flexural Strength ◽  
Impact Angle ◽  
X Ray Diffraction ◽  
Erosion Behavior ◽  
Sand Erosion ◽  
Transmission Electron ◽  
Erosion Test ◽  
Ball Milling Technique ◽  
Impact Angles

In the present work, the mechanical and the tribological properties of eggshell nanoparticulate epoxy biocomposite were studied. The nanoparticles of eggshell were synthesized by planetary ball milling technique. Synthesized eggshell nanoparticulate were characterized with the aid of Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray diffraction analysis, and Fourier Transform Infrared (FTIR) Spectroscopy. Fabrication of eggshell nanoparticulate epoxy biocomposite was done by hand lay-up technique with different weight percentages (1 wt%, 2 wt%, 3 wt%, 4 wt%) of eggshell nanoparticles. To examine the solid particle erosion behavior of eggshell nanoparticulate epoxy biocomposite, four different impact angles (30°, 45°, 60°, 90°) and three different velocities (101 m s−1, 119 m s−1, 148 m s−1) were chosen. The effect of eggshell nanoparticles incorporation on the tensile properties, hardness, and the flexural properties was also investigated. The fractured surfaces of the tensile test, flexural test, and erosion test samples were examined with a SEM for morphological analysis. It was found that the eggshell nanoparticulate addition has a fruitful effect on tensile and flexural strength. The maximum tensile strength was found for 2 wt% nanoparticles addition, while the maximum flexural strength was found for 3 wt% of nanoparticles addition. The sand erosion study established a maximum wear rate at 60° of impact angle. The maximum erosion resistance was found in 2 wt% of eggshell nanoparticulate concentration.

Preparation and characterization of reactive liquid rubbers toughened epoxy-clay hybrid nanocomposites

2016 ◽  
Vol 36 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Jowita Szymańska ◽  
Mohamed Bakar ◽  
Marcin Kostrzewa ◽  
Marino Lavorgna
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Epoxy Resin ◽  
Xrd Analysis ◽  
Peak Height ◽  
Hybrid Nanocomposites ◽  
Flexural Properties ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Reactive Liquid

Abstract The present work investigates the effect of organomodified nanoclay (ZW1) and butadiene-acrylonitrile copolymer terminated with different amine groups (amine-terminated butadiene-acrylonitrile, ATBN) on the properties and morphology of epoxy resin. The morphologies of the nanocomposites were analyzed by X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The nanocomposites structure was confirmed by Fourier transform infrared (FTIR) spectroscopy, XRD and TEM. The properties evaluation showed that the polymeric modifier and nanoclays strongly influence the fracture toughness and flexural properties of the nanocomposites. Hybrid epoxy composites containing 1% ZW1 and ATBN rubbers showed improved fracture toughness and flexural properties in comparison with unmodified epoxy resin. FTIR spectra showed an increase in the hydroxyl peak height peak height of 3360 cm-1 due to reactive rubber incorporation. SEM micrographs of hybrid epoxy resin nanocomposites showed significant plastic yielding of the polymer matrix with stratified structures and more cavitations, explaining thus the enhancement of fracture toughness and flexural strength of the nanocomposites.

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