Bonding Strength and Microstructure of Cermet/Cu-Based Alloy Composite Brazed Coatings

2005 ◽  
Vol 297-300 ◽  
pp. 154-159 ◽  
Author(s):  
Xin Hong Wang ◽  
Zeng Da Zou ◽  
Min Zhang ◽  
Si Li Song ◽  
Shi Yao Qu
Keyword(s):  
Electron Microscopy ◽  
Tensile Strength ◽  
Composite Coatings ◽  
Wear Property ◽  
Alloy Composite ◽  
X Ray Diffraction ◽  
Interfacial Diffusion ◽  
X Ray ◽  
Transmission Electron ◽  
The Matrix

WC-TiC-Co cermet and CuZnNi alloy composite coatings were produced on mild steel by a high temperature inside-furnace brazing technique. The microstructure, phase constituents and interfacial diffusion behavior of cermet and Cu-based alloy were investigated by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron probe microanalysis (EPMA) and X-ray diffraction. The tensile strength and wear property of composite coatings were also investigated. The results show that crème particles were not decomposed severely during the inside- furnace brazing process. The microstructure of the matrix is α and β phases. Diffusion occurred at the cermet/Cu-based alloy interface. The tensile strength of the composite coatings reached 240-300MPa, which depended on the brazing temperature and was far higher than that of the flame hardfacing layers. Cermet fracture was basically a brittle fracture in nature and matrix involves ductile fracture.

Upconversion Luminescence Properties of NaYF4 Nanocrystals Precipitated Nd3+/Yb3+/Ho3+ Tri-Doped Oxyfluoride Glass Ceramics

2016 ◽  
Vol 16 (4) ◽  
pp. 3744-3748 ◽  
Author(s):  
Yuan Gao ◽  
Yuebo Hu ◽  
Dacheng Zhou ◽  
Jianbei Qiu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Energy Transfer Process ◽  
Upconversion Luminescence ◽  
Glass Ceramics ◽  
X Ray Diffraction ◽  
Oxyfluoride Glass ◽  
X Ray ◽  
Transmission Electron ◽  
The Matrix

Transparent oxyflouride glass ceramics composed of SiO2–Al2O3–Na2O–NaF–YF3 tri-coped with Nd3+/Yb3+/Ho3+ were prepared by thermal treatment. Segregation of NaYF4 nanocrystals in the matrix was confirmed from structural analysis by means of X-ray diffraction and transmission electron microscopy. Compared with glass samples, very strong green upconversion (UC) luminescence due to the Ho3+:(4F5, 5S2)→5I8 transition was observed in the glass ceramics under 808 nm excitation. It was found that upconversion intensity of Ho3+ strongly depends on the Nd3+ concentration, and the energy transfer process from Nd3+ to Ho3+ via Yb3+ was proposed.

Preparation of PVC/Kaolin Nanocomposites through Solid State Shear Compounding Based on Pan-Milling

2011 ◽  
Vol 694 ◽  
pp. 350-354 ◽  
Author(s):  
Kan She Li ◽  
Ying Hong Chen ◽  
Hong Mei Niu ◽  
Jian Jun Chen
Keyword(s):  
Electron Microscopy ◽  
Tensile Strength ◽  
Solid State ◽  
Impact Strength ◽  
Ambient Temperature ◽  
Mechanical Tests ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Filled Composite

Solid state shear compounding technology (S3C) based on pan-milling is an effective method to prepare polymer/layered mineral composites with nano intercalating structure. The PVC/Kaolin compounding powders were successfully prepared by pan-milling at ambient temperature, and then the PVC/Kaolin nanocomposites were processed by moulding The structure and properties of PVC/Kaolin compounding powder and nanocomposites were investigated by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and mechanical tests. The results showed that the mechanical properties of PVC/Kaolin nanocomposites prepared through S3C based on pan-milling 30 cycles at ambient temperature including elongation, tensile strength and notched impact strength were remarkably improved compared with conventional filled composites. The elongation of PVC / Kaolin nanocomposites with 4 %wt. Kaolin was 274.6%, which is 187.3 % higher than that for a conventional filled composite. The tensile strength was 54.0 MPa, which is 6.3 MPa higher than that for a conventional filled composite. The tensile strength of the nanocomposites with 8 %wt. Kaolin was 57.5 MPa, which is 9.1 MPa higher than that for a conventional filled composite. At the same time, the notched impact strength was 4.9 kJ/m2, which is 1.0 kJ/m2 higher than a conventional filled composite. Strengthening and toughening for PVC were synchronously realized. XRD, SEM and TEM verified that S3C based on pan-milling realized synchronously pulverizing, dispersion and compounding of PVC with kaolin Through 25-30 cycles pan-milling, PVC and Kaolin powders imbedded each other and made into uniform PVC/Kaolin compounding powders and nanocomposites. The strip flake of Kaolin particles with thickness less than 50 nanometer and the aspect ratio of 10 times dispersed homogeneously in the PVC matrix.

scholarly journals Investigation of the γ′ Precipitates Dissolution in a Ni-Based Superalloy During Stress-Free Short-Term Annealing at High Homologous Temperatures

2021 ◽  
Author(s):  
Łukasz Rakoczy ◽  
Małgorzata Grudzień-Rakoczy ◽  
Fabian Hanning ◽  
Grzegorz Cempura ◽  
Rafał Cygan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Short Term ◽  
X Ray ◽  
Transmission Electron ◽  
Thermodynamic Simulations ◽  
The Matrix ◽  
Increasing Temperature

AbstractThe equiaxed Ni-based superalloy René 108 was subjected to short-term annealing at five temperatures between 900 °C and 1100 °C. The phase composition, phase lattice parameters, microstructure, stereological parameters, and chemical composition of γ′ precipitates were investigated by thermodynamic simulations, X-ray diffraction, scanning and transmission electron microscopy, and energy-dispersive X-ray spectroscopy. Analysis of the γ and γ′ lattice parameters using the Nelson-Riley extrapolation function showed that the misfit parameter for temperatures 900 °C to 1050 °C is positive (decreasing from 0.32 to 0.11 pct). At 1100 °C, the parameter becomes negative, δ = − 0.18 pct. During the short-term annealing, γ′ precipitates dissolution occurred progressing more rapidly with increasing temperatures. The surface fraction of γ′ precipitates decreased with increasing temperature from 0.52 to 0.34. The dissolution of γ′ precipitates did not only proceed through uninterrupted thinning of each individual precipitate, but also included more complex mechanisms, including splitting. Based on transmission electron microscopy, it was shown that after γ′ precipitates dissolution, the matrix close to the γ/γ′ interface is strongly enriched in Co and Cr and depleted in Al.

Mechanical, microstructural properties and cell adhesion of Sr/Se-hydroxyapatite/graphene/polycaprolactone nanofibers

2020 ◽  
pp. 089270572091278 ◽  
Author(s):  
Reem Al-Wafi ◽  
SF Mansour ◽  
MK Ahmed
Keyword(s):  
Electron Microscopy ◽  
Tensile Strength ◽  
Microstructural Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nanofibrous Scaffolds ◽  
Transmission Electron ◽  
Fesem Micrographs

Electrospun nanofibrous scaffolds containing co-dopant of Sr/Se into carbonated hydroxyapatite has been synthesized in situ with graphene (G) nanosheets and carried on polycaprolactone at different contributions of G. The powder and the nanofibrous samples were investigated using X-ray diffraction, transmission electron microscopy, and field emission scanning electron microscopy (FESEM). The FESEM micrographs show that the highest content of G (0.2 G) was formed in non-oriented/rough/cracked fibers with diameters around 0.3–0.4 µm at the maximum. The tensile strength of nanofibrous scaffolds was improved with the addition of G nanosheets and the maximum tensile strength of 0.2 G was around 6.39 ± 0.24 MPa, while the minimum cell viability ratio was about 94.4 ± 3.2% for the free G nanofibers. The in vitro attachment of HFB4 cell lines was investigated and it showed that nanofibrous scaffolds have induced cells to be proliferated and spread on the nanofibrous scaffolds’ surface. This behavior of cells growth encourages more investigations for these nanofibrous scaffolds to be promoted for clinical applications.

Microwave NIMs: Using a Uniform AC Electric Field for Manipulating Ag Nanorods Embedded in Co0.05Ti0.95O2 Matrix

NANO ◽  
2016 ◽  
Vol 11 (08) ◽  
pp. 1650084
Author(s):  
Zahra Khorshidi ◽  
Ali Bahari
Keyword(s):  
Electron Microscopy ◽  
Electric Field ◽  
Sol Gel ◽  
Negative Permittivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ac Electric Field ◽  
Transmission Electron ◽  
Permittivity And Permeability ◽  
The Matrix

In the present work, we synthesized a composite medium consisting of Ag nanorods embedded in Co[Formula: see text]Ti[Formula: see text]O2 matrix (Ag/CTO) using the sol-gel method. We applied a uniform AC electric field at the beginning of gelation and during drying for manipulating Ag nanorods in the matrix. The structure and morphology characterizations of Ag/CTO nanocomposites were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The permittivity and permeability behaviors of samples were investigated. Results showed that for the sample dried in the existence of the electric field, simultaneous negative permittivity and permeability were realized. These results imply the realization of double negative properties in this sample. Therefore, this work suggests that Ag/Co[Formula: see text]Ti[Formula: see text]O2 nanocomposites can be introduced as a negative index metamaterials (NIMs).

Microstructural and Mechanical Properties of Polyester/Nanoclay Nanocomposites: Microstructure-Mixing Strategy Correlation

2011 ◽  
Vol 1312 ◽  
Author(s):  
Hamid Dalir ◽  
Rouhollah D. Farahani ◽  
Vireya Nhim ◽  
Benjamin Samson ◽  
Martin Lévesque ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Strain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Roll Mill ◽  
The Matrix ◽  
Polyester Matrix ◽  
Excellent Improvement

ABSTRACTDifferent nanoclay mixing strategies using a three-roll mill and ultrasonication is proposed to obtain the desired polyester/nanoclay dispersion, intercalation, and exfoliation. The dispersion states of the modified nanoclay in polymer with 2, 4 and 6 wt% loading were characterized with X-ray diffraction, scanning electron microscopy (SEM), and low and high magnification transmission electron microscopy (TEM). The mechanical properties of the clay-reinforced polyester nanocomposites were a function of the nature and the content of the clay in the matrix. The nanocomposite containing 4 wt% modified Cloisite® 15A exhibits excellent improvement in modulus (by ~51%) and tensile strength (by ~12%) with a decrease in fracture strain (by ~26%) and fracture energy (by ~17%). These mechanical characteristic changes can be attributed to the dispersion, intercalation, and exfoliation of the nanoclays inside the polyester matrix.

Research on Solution and Aging Treatment of Mg-7Zn-3Al Alloy

2007 ◽  
Vol 561-565 ◽  
pp. 247-250
Author(s):  
Jing Zhang ◽  
Fu Sheng Pan ◽  
Ru Lin Zuo
Keyword(s):  
Electron Microscopy ◽  
Grain Boundary ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Aging Treatment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Quantitative Image ◽  
The Matrix

Effect of solution and aging treatment on the microstructure of Mg-7Zn-3Al alloy is studied by using optical microscopy, scanning electron microscopy, X-ray diffraction, transmission electron microscopy and quantitative image analysis. The results show that the as-aged microstructure is composed of α-Mg matrix, grain boundary τ (Mg32(Al,Zn)49 ) phase, and fine dispersed τ particles inside the grain. The solution degree has significant effects on the formation, morphology, and size of the grain boundary τ phase. The volume fraction and the size of the undissolved eutectic τ phase decrease with the increase of solution time treated at 325°C. Through sufficient solution treatment, discontinuous eutectic τ phase retains fine strip morphology after aging, in contrast to the microstructure in sample undergone insufficient solution which manifests as-cast feature, while at the same time nano-sized particles precipitate out from the matrix. The precipitates display paralleled short bar, having certain orientation relationship with the matrix.

Development and characterization of novel polybutylene nanocomposites

2016 ◽  
Vol 51 (1) ◽  
pp. 95-108 ◽  
Author(s):  
Khaled Alfadhel ◽  
Adam Al-Mulla ◽  
Bader Al-Busairi
Keyword(s):  
Electron Microscopy ◽  
Tensile Strength ◽  
Initial Period ◽  
Mechanical Analysis ◽  
X Ray Diffraction ◽  
Elongation At Break ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
The Matrix

Polybutylene/starch/nanoclay composite blends were prepared by melt extrusion technique. Maleic anhydride grafted polybutylene was used as a compatibilizer. The nanocomposites were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, rheological, and mechanical analysis. Addition of compatibilizer to the polybutylene/starch/nanoclay showed dispersion and nucleation related to the nanoclay in the polybutylene matrix. An increase in the mechanical properties like modulus and tensile strength at break and a decrease in the elongation at break were observed on the addition of compatibilizer to the matrix compared to that of uncompatibilized matrix. The biodegradability of the nanocomposites was studied using the landfill burial test. The blends subjected to the burial test were evaluated for their tensile properties. The results revealed that the tensile strength and elongation at break of the compatibilized nanocomposites decreased after 80 days of land burial test compared to the initial period.

Synthesis, Characterization and Photocatalytic Activity of AgCl Loaded on TiO2/SBA-15 Composites

2012 ◽  
Vol 557-559 ◽  
pp. 249-253
Author(s):  
Ge Er Yi ◽  
Chun Fang Du ◽  
Yi Guo Su ◽  
Zhi Liang Liu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photocatalytic Decomposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
The Matrix ◽  
Photocatalytic Performances ◽  
Adsorption Desorption

TiO2/SBA-15 and AgCl loaded on TiO2/SBA-15(AgCl-TiO2/SBA-15) composites were synthesized by a facile method. All products were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and N2adsorption-desorption analysis. Photocatalytic activities of the composites were assessed by the photocatalytic decomposition of methyl orange (MO). The results indicated that TiO2or TiO2-AgCl existed in the matrix SBA-15, which reduced the specific surface area, pore volume and pore size of the matrix. The photocatalytic performances of TiO2/SBA-15 were higher than that of pure TiO2, and the resultant AgCl-TiO2/SBA-15 composites showed much higher photocatalytic performances than TiO2/SBA-15.

A Study on Ni–TiN Coatings Produced by Ultrasonic Pluse Electrodeposition

2012 ◽  
Vol 562-564 ◽  
pp. 269-272
Author(s):  
Fa Feng Xia ◽  
Chun Hua Ma ◽  
Yi Fang Yin ◽  
Liang Miao
Keyword(s):  
Electron Microscopy ◽  
Scanning Probe Microscopy ◽  
Composite Coatings ◽  
Scanning Probe ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tin Coatings ◽  
Tin Nanoparticles ◽  
Transmission Electron ◽  
Metallurgical Structure

Nanocomposite Ni–TiN coatings were prepared by ultrasonic pluse electrodeposition and the effects of ultrasonication on the coatings were studied. X-Ray diffraction analysis was utilized to detect the crystalline and amorphous characteristics of the composite coatings. The surface morphology and metallurgical structure were observed by scanning electron microscopy, high-resolution transmission electron microscopy and scanning probe microscopy. The results show that ultrasonication has great effects on TiN nanoparticles in composite coatings. Moreover, the introduction of ultrasonication and TiN particles led to the formation of smaller nickel grains. The average grain diameter of TiN particles was 33 nm, while Ni grains measured approximately 53 nm.

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