scholarly journals Development of TiB and nanocrystalline Ti-reinforced novel hybrid Ti nanocomposite produced by powder metallurgy

2022 ◽  
Author(s):  
D. A. Angel ◽  
T. Mikó ◽  
F. Kristály ◽  
M. Benke ◽  
Z. Gácsi
Keyword(s):  
Electron Microscopy ◽  
Powder Metallurgy ◽  
Hybrid Composites ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Transformation Mechanism ◽  
Vacuum Sintering ◽  
X Ray ◽  
Titanium Monoboride ◽  
Scanning Electron

AbstractTitanium monoboride (TiB) whisker-reinforced titanium (Ti) matrix composites were produced by powder metallurgy, through vacuum sintering. TiB is formed by thermal decomposition of TiB2 precursor. In addition, a new hybrid composite was developed by admixing nanograined and nanocrystalline (more important) Ti to enhance the transformation mechanism of TiB2 to TiB phase. The morphology and particle size of the initial powders, mixtures and the microstructure of the composites have been studied by scanning electron microscopy (SEM). The phase analysis and transformation monitoring were performed by X-ray diffraction (XRD). The sintered composites were also subjected to compressive strength and hardness measurements. According to XRD results, through the addition of nanocrystalline Ti, a probable enhancement of the TiB2 → TiB transformation occurred producing more TiB whiskers in the hybrid composites. All samples of the hybrid composites exhibited improved yield strength (1365 MPa) and hardness (358 HV) compared to the non-hybrid ones 927 MPa and 254 HV, respectively. Graphical abstract

scholarly journals Chemical Stability of Ti3C2 MXene with Al in the Temperature Range 500–700 °C

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1979 ◽  
Author(s):  
Jing Zhang ◽  
Shibo Li ◽  
Shujun Hu ◽  
Yang Zhou
Keyword(s):  
Electron Microscopy ◽  
Chemical Stability ◽  
Metal Matrix ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Transmission Electron ◽  
Work First ◽  
Scanning Electron

Ti3C2Tx MXene, a new 2D nanosheet material, is expected to be an attractive reinforcement of metal matrix composites because its surfaces are terminated with Ti and/or functional groups of –OH, –O, and –F which improve its wettability with metals. Thus, new Ti3C2Tx/Al composites with strong interfaces and novel properties are desired. To prepare such composites, the chemical stability of Ti3C2Tx with Al at high temperatures should be investigated. This work first reports on the chemical stability of Ti3C2Tx MXene with Al in the temperature range 500–700 °C. Ti3C2Tx is thermally stable with Al at temperatures below 700 °C, but it reacts with Al to form Al3Ti and TiC at temperatures above 700 °C. The chemical stability and microstructure of the Ti3C2Tx/Al samples were investigated by differential scanning calorimeter, X-ray diffraction analysis, scanning electron microscopy, and transmission electron microscopy.

Experimental Investigation of Aluminium Hybrid Composites Reinforced with ZnS, TiO2 and BaTiO3 Produced Through Powder Metallurgy

2021 ◽  
Vol 13 (3) ◽  
Author(s):  
S. Rajeshkannan ◽  
I. Manikandan ◽  
M. Vigneshkumar
Keyword(s):  
Powder Metallurgy ◽  
Hybrid Composites ◽  
Brinell Hardness ◽  
High Hardness ◽  
High Strength ◽  
Hardness Test ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Testing Instrument ◽  
X Ray

Semiconductors like ZnS, TiO2 and BaTiO3 were reinforced with Al-Al2O3 Metal Matrix Composites (MMCs) and were made through powder metallurgy in order to have high strength, high hardness and good thermal conductivity compared with conventional materials. Three MMC of test specimens were prepared with varying reinforcement ratio Al-Al2O3-ZnS(94-5-1), Al-Al2O3-TiO2(94-5-1), Al-Al2O3-BaTiO3(94-5-1) percentage by weight respectively. The hardness test has been made by using Brinell hardness testing instrument. Hardness test revealed that the addition of reinforcement TiO2, BaTiO3 increases the hardness value. However, the addition of ZnS to the Al-Al2O3 MMCs showed decrease in the hardness value. The crystal structure of the 3 composites were examined through X-Ray Diffraction (XRD) peaks.

Microstructure Evolution of In Situ Synthesized VC Reinforced Iron Matrix Composites

2012 ◽  
Vol 217-219 ◽  
pp. 71-74
Author(s):  
Jing Wang ◽  
Si Jing Fu ◽  
Shu Yong Jiang ◽  
Hong Cheng
Keyword(s):  
Electron Microscopy ◽  
In Situ Synthesis ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Iron Matrix ◽  
X Ray ◽  
Matrix Microstructure ◽  
The Matrix ◽  
Scanning Electron

Iron matrix composite reinforced with VC reinforcements was produced by in situ synthesis technique. The microstructure of the composites was characterized by X-ray diffraction and scanning electron microscopy. The micrographs revealed the morphology and distribution of the reinforcements. The results show that the composite consists of VC carbide as the reinforcing phase and α-Fe as the matrix. The distribution of spherical VC particulates in iron matrix is uniform, and the matrix microstructure of Fe-VC composite is pearlite.

Low Temperature Oxidation Behaviors of CNTs/MoSi2 Composites

2014 ◽  
Vol 983 ◽  
pp. 116-120
Author(s):  
Houan Zhang ◽  
He Jian Wu ◽  
Jia Lin ◽  
Si Yong Gu ◽  
Lei Yu
Keyword(s):  
Electron Microscopy ◽  
Molybdenum Disilicide ◽  
Phase Identification ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
Low Temperature Oxidation ◽  
Temperature Oxidation ◽  
X Ray ◽  
Scanning Electron ◽  
Oxidation Behaviors

Molybdenum disilicide (MoSi2) matrix composites with various contents of carbon nanotubes (CNTs) were fabricated by sintering in vacuum at 1550 °C for 1 h. The oxidation behaviors of CNTs/MoSi2composites at 400 °C and 500 °C for 200 h in air were studied. Results showed that the weight loss of CNTs/MoSi2composites increased with the increase of CNTs content. “Pest” phenomenon happened at 400 °C but not at 500 °C. Phase identification and microstructure of the samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that many MoO3whiskers and microcracks only occurred on the surface of CNTs/MoSi2composites when oxidized at 400 °C in air, which leaded to the catastrophic disintegration of CNTs/MoSi2composites.

Microstructural and Mechanical Properties of Ti3Al-Based Intermetallics Produced by Powder Metallurgy

2005 ◽  
Vol 494 ◽  
pp. 211-216 ◽  
Author(s):  
B. Dimčić ◽  
M. Vilotijević ◽  
D. Božić ◽  
D. Rajnović ◽  
M.T. Jovanović
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Room Temperature ◽  
Solution Treatment ◽  
Microstructural Characterization ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The structural and compression mechanical properties of Ti3Al-based intermetallics produced by powder metallurgy techniques have been studied. The as-milled powders were compacted by hot pressing to non-porous homogenous compacts. Prior to compression tests, all compacts were homogenized by a solution treatment at 1050°C (a+β region) for 1h, followed by water quenching. The compression tests were performed from room temperature to 500°C in vacuum at a strain rate of 1 3 10 4 . 2 − − × s . Detailed microstructural characterization was evaluated by scanning electron microscopy (SEM), followed by energy dispersive spectroscopy (EDS) and X-ray diffraction analysis.

scholarly journals Additive Effect of Carbon Nanostructures on the Microstructures and Properties of Pitch Derived Carbon Foam Composites

2021 ◽  
Author(s):  
muhammad khan ◽  
amjad hussain ◽  
hammad Ahmad ◽  
Li Tiehu ◽  
Amir Zada ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanostructures ◽  
Hybrid Composites ◽  
Carbon Foam ◽  
X Ray Diffraction ◽  
Structural Morphology ◽  
X Ray ◽  
Multi Wall Carbon Nanotubes ◽  
Maximum Compressive Strength ◽  
Scanning Electron

Abstract In the present work, carbon foam (CF) coupled multi-wall carbon nanotubes (MWCNTs) and CF/MWCNTs coupled nanodiamond (NDs) hybrid composites were prepared by the direct treatment of MWCNTs and NDs with pretreatment pitches through foaming, graphitization, and carbonization process. Both series of CF composites were compared and explored by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy techniques. It was investigated that the structural morphology, pore size and pore uniformity upgraded with the increment of MWCNTs content, however, the effect of ND particles in this aspect was more influential. Furthermore, the effect of additive loading of MWCNTs and NDs on the mechanical, electrical and thermal properties of CF composites were checked. The results revealed that maximum compressive strength 15.8 MPa and electrical conductivity 30.2×103 S/m of CFs were obtained at 4 wt.% MWCNTs and ND loadings respectively. While the maximum thermal conductivity value of 32.2 Wm-1k-1 was revealed by CFs having 2 wt.% MWCNTs and NDs loadings.

Preparation and Study on the Properties of Gypsum Whiskers Reinforced Resin Matrix Composites

2013 ◽  
Vol 327 ◽  
pp. 189-192
Author(s):  
Chuan Wei Du ◽  
Guo Zhong Li
Keyword(s):  
Electron Microscopy ◽  
Cross Section ◽  
Strengthening Mechanism ◽  
Resin Matrix ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Resin Matrix Composite ◽  
The Stability ◽  
Scanning Electron

In this paper, gypsum whiskers reinforced resin matrix composites were prepared with the desulfurization gypsum by the technology of atmospheric acidification. The influences of stabilization reagent on the stability of the gypsum whiskers were studied. Meanwhile, the enhanced effects of surface treatment and different contents of gypsum whiskers on the resin matrix composite were analyzed. Scanning electron microscopy, metallographic microscopy, X-ray diffraction test were taken to conduct analysis of the morphology and the aspect ratio of gypsum whiskers. Besides, the mechanical properties of gypsum whiskers reinforced resin matrix composites were tested, and cross-section scanning was used to analyze the strengthening mechanism.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

Environmental scanning electron microscopy of fresh human gallstones reveals new morphologies of precipitated calcium salts

1992 ◽  
Vol 50 (2) ◽  
pp. 1322-1323
Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
X Ray Diffraction ◽  
Calcium Salts ◽  
Cholesterol Gallstones ◽  
X Ray ◽  
Ca Carbonate ◽  
Scanning Electron

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.

Photocatalytic activity of TiO2 synthesized by anodization and anodic spark deposition

MRS Advances ◽  
2020 ◽  
Vol 5 (61) ◽  
pp. 3141-3152
Author(s):  
Alma C. Chávez-Mejía ◽  
Génesis Villegas-Suárez ◽  
Paloma I. Zaragoza-Sánchez ◽  
Rafael Magaña-López ◽  
Julio C. Morales-Mejía ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Surface Characteristics ◽  
Amorphous Solids ◽  
X Ray Diffraction ◽  
X Ray ◽  
Catalytic Activities ◽  
Anodic Spark Oxidation ◽  
Porous Surfaces ◽  
Scanning Electron

AbstractSeveral photocatalysts, based on titanium dioxide, were synthesized by spark anodization techniques and anodic spark oxidation. Photocatalytic activity was determined by methylene blue oxidation and the catalytic activities of the catalysts were evaluated after 70 hours of reaction. Scanning Electron Microscopy and X Ray Diffraction analysis were used to characterize the catalysts. The photocatalyst prepared with a solution of sulfuric acid and 100 V presented the best performance in terms of oxidation of the dye (62%). The electric potential during the synthesis (10 V, low potential; 100 V, high potential) affected the surface characteristics: under low potential, catalyst presented smooth and homogeneous surfaces with spots (high TiO2 concentration) of amorphous solids; under low potential, catalyst presented porous surfaces with crystalline solids homogeneously distributed.

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