scholarly journals Effects of milling temperature and time on phase evolution of Ti-based alloy

2021 ◽  
pp. 55-55
Author(s):  
F. Kristaly ◽  
M. Sveda ◽  
A. Sycheva ◽  
T. Miko ◽  
A. Racz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Milling Time ◽  
Nanocrystalline Structure ◽  
Phase Evolution ◽  
High Energy ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Scanning Calorimetry ◽  
Cell Parameters ◽  
Milling Temperature

Ti50Cu25Ni20Sn5 (at.%) powder was subjected to high-energy ball milling at room temperature and -78?C. As a function of the milling time, evaluation of phases, morphology and the refinement of grain size were investigated by scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and laser-diffraction particle size analysis (PSA). The transformation of the crystalline structure into an amorphous structure and then the transformation into a nanocrystalline structure during further milling was detected. The stress-induced martensitic transformation has taken place after 30 min milling time at both temperatures, the cubic Cu(Ni,Cu)Ti2 phase transforms into the orthogonal structure. The hardness value of powders after 150 min milling time increases from 506 to 780 HV0.01. The milling temperature does not significantly influence the amount of amorphous fraction (33-36 wt.%) but the composition of amorphous content is more influenced by temperature. The interval of crystallite size was between 1.2 and 11.7 nm after 180 min of milling. The amount and the cell parameters of the Sn-containing phases are different between the two milling experiments, owing to the diffusion coefficients of the Sn atom differ to a large extent.

High Energy Milling of Alumina Synthesized by Combustion Reaction Using a Vertical Shaft Attritor Mill: Influence of the Milling Time Length

2015 ◽  
Vol 820 ◽  
pp. 155-160 ◽  
Author(s):  
Mirele Costa da Silva ◽  
N.C.O. Costa ◽  
D.S. Lira ◽  
Joelda Dantas ◽  
A.C.F.M. Costa ◽  
...  
Keyword(s):  
Milling Time ◽  
Particle Diameter ◽  
High Energy ◽  
Particle Size Analysis ◽  
Combustion Reaction ◽  
Size Analysis ◽  
Average Particle ◽  
Length Variation ◽  
Average Particle Diameter ◽  
Time Length

Among the vast applications in which the α-alumina can apply, the literature has reported researches which aim to achieve better features of these materials varying the obtainment methodology and some post-obtainment techniques. Thus, this paper aims to evaluate how different milling time lengths of 15, 30, 45 and 60 minutes alter the structure and morphology of α-alumina powders synthesized by combustion reaction. The time and temperature of the combustion reaction were evaluated during the synthesis of the alumina. The samples of non-milled and milled alumina were characterized by XRD and particle size analysis. The results showed that the maximum achieved temperature of reaction was 598°C. The milling time length variation did not alter the stable α-Al2O3majority crystal phase present in all samples. The average particle diameter was reduced from 23.3 to 10.5 μm comparing the non-milled and the sample milled for 60s.

Effect of SiC Nanoparticles Content and Milling Time on the Characteristics of Al/SiC Nanocomposite Powders Produced via Mechanical Milling

2013 ◽  
Vol 829 ◽  
pp. 505-509 ◽  
Author(s):  
Farshad Akhlaghi ◽  
Sareh Mosleh-Shirazi
Keyword(s):  
Crystal Size ◽  
Milling Time ◽  
Matrix Alloy ◽  
High Energy ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Sic Nanoparticles ◽  
Sic Particles ◽  
The Matrix ◽  
Nanocomposite Powders

In the present study high energy ball milling was utilized to produce aluminum (Al-6061) matrix nanocomposite powders reinforced with nanosilicon carbide (SiC) particles. The starting materials containing different percentages (1,3 or 5 wt.%) of nanoSiC particles (25-50 nm) and Al (38-63 μm) were co-milled for different times (16, 20, 24 h) to achieve nanocomposite powders. The crystal size of powders were evaluated by quantitative XRD analysis. Laser particle size analysis was used to evaluate the size of powders during milling. The microstructure of powders and their microhardness values were evaluated by Scanning Electron Microscopy (SEM) and a microhardness tester respectively. The results indicated that the crystal size of the matrix alloy decreased by milling time. The increased SiC content up to 3% resulted in increased microhardness of the powders. However, further increase of SiC to 5% resulted in decreased microhardness due to agglomeration. It was concluded that the maximum microhardness together with a uniform distribution of SiC particles within the matrix alloy was obtained after 20 h milling of powder mixture containing 3% of SiC nanoparticles.

Sol-gel derived Nd1/3La1/3Ca1/3MnO3: Phase evolution and preparation of films and nanopowders

2007 ◽  
Vol 22 (6) ◽  
pp. 1737-1743 ◽  
Author(s):  
A. Pohl ◽  
G. Westin
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Single Phase ◽  
Sol Gel ◽  
Phase Evolution ◽  
Perovskite Oxide ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Cell Parameters ◽  
Transmission Electron

An all-alkoxide sol-gel route to the formation of Nd1/3La1/3Ca1/3MnO3thin films and powders has been developed. The microstructural evolution on heat treatment of the gel to yield the perovskite oxide was monitored by means of thermogravimetric analysis-differential scanning calorimetry, powder x-ray diffraction (XRD), Fourier transform infrared spectroscopy, and transmission electron microscopy (TEM)-energy dispersive spectroscopy (EDS). It was found that the amorphous gel consists of hydrated oxo-carbonate without organic residues, and on heating it decomposes in several steps, finally forming single-phase perovskite at 680 °C. Further heating results in only slight changes in the cell parameters and crystal growth. Films were prepared by spin coating, followed by heat treatment in air to a temperature of 800 °C, and studied by scanning electron microscopy, TEM-EDS, and XRD. Films on Al2O3were more porous, while films on Pt–TiO2–SiO2–Si were rather dense and consisted of areas with different crystal orientations.

scholarly journals Structural, Morphological and thermal properties of Nano filler Produced from Date Palm-based Micro Fibers (Phoenix Dactylifera L.)

2021 ◽  
Author(s):  
Othman Y Alothman ◽  
H.M. Shaikh ◽  
Basheer A. Alshammari ◽  
Mohammad Jawaid
Keyword(s):  
Electron Microscopy ◽  
Date Palm ◽  
Low Cost ◽  
Analytical Techniques ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Green Composite ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Wide Range

Abstract In this century, the development of nano-sized filler from biomass material has become the main focus of industries in achieving their final green composite product for wide range of applications. From commercial and environmental point of view, fragmentation and downsizing of waste lignocellulosic fibers without chemical treatments into small size particles is a viable option. In this study, an attempt was made to produce nano-sized lignocellulosic fillers from date palm micro fibers via simple mechanical ball milling process. The resultant nanofillers as well as the microfibers were characterized in details by various analytical techniques, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), particle size analysis (PSA), Energy Dispersive X-Ray (EDX), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) to assess their structure­—property relationship. From microscopy examination, the nanofillers showed a heterogeneous mix of irregular shaped particles, and while having a size ranging of 30-110 nm in width and 1-10 mm length dimensions. Also, the crystallography analysis revealed the crystallinity had mildly declined from microfibers (71.8%) to nanofiller (68.9%) due to amorphization effect. As for thermal analysis, the nanofillers exhibited relatively stable in both heat resistance and thermos changing behavior, suggesting its suitability for composite fabrication process at high temperature. Thus, the produced nanofillers can be used as a low cost reinforcing agent in the future for versatile polymer-based composite systems.

scholarly journals Mining Wastes of an Albite Deposit as Raw Materials for Vitrified Mullite Ceramics

Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 232
Author(s):  
Pedro J. Sánchez-Soto ◽  
Eduardo Garzón ◽  
Luis Pérez-Villarejo ◽  
George N. Angelopoulos ◽  
Dolores Eliche-Quesada
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Phase Evolution ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Mining Wastes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Maximum Value

In this work, an examination of mining wastes of an albite deposit in south Spain was carried out using X-ray Fluorescence (XRF), X-ray diffraction (XRD), particle size analysis, thermo-dilatometry and Differential Thermal Analysis (DTA) and Thermogravimetric (TG) analysis, followed by the determination of the main ceramic properties. The albite content in two selected samples was high (65–40 wt. %), accompanied by quartz (25–40 wt. %) and other minor minerals identified by XRD, mainly kaolinite, in agreement with the high content of silica and alumina determined by XRF. The content of Na2O was in the range 5.44–3.09 wt. %, being associated with albite. The iron content was very low (<0.75 wt. %). The kaolinite content in the waste was estimated from ~8 to 32 wt. %. The particle size analysis indicated values of 11–31 wt. % of particles <63 µm. The ceramic properties of fired samples (1000–1350 °C) showed progressive shrinkage by the thermal effect, with water absorption and open porosity almost at zero at 1200–1250 °C. At 1200 °C, the bulk density reached a maximum value of 2.38 g/cm3. An abrupt change in the phase evolution by XRD was found from 1150 to 1200 °C, with the disappearance of albite by melting in accordance with the predictions of the phase diagram SiO2-Al2O3-Na2O and the system albite-quartz. These fired materials contained as main crystalline phases quartz and mullite. Quartz was present in the raw samples and mullite was formed by decomposition of kaolinite. The observation of mullite forming needle-shape crystals was revealed by Scanning Electron Microscopy (SEM). The formation of fully densified and vitrified mullite materials by firing treatments was demonstrated.

scholarly journals Development of a Solid Dispersion of Nystatin with Maltodextrin as a Carrier Agent: Improvements in Antifungal Efficacy against Candida spp. Biofilm Infections

2021 ◽  
Vol 14 (5) ◽  
pp. 397
Author(s):  
Carlos Benavent ◽  
Carlos Torrado-Salmerón ◽  
Santiago Torrado-Santiago
Keyword(s):  
Antifungal Activity ◽  
Solid Dispersions ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Candida Spp ◽  
Microbiological Techniques ◽  
Characterization Studies ◽  
Candida Albicans Biofilms

The aim of this study was to improve the treatment of Candida albicans biofilms through the use of nystatin solid dispersions developed using maltodextrins as a hyperosmotic carrier. Characterization studies by differential scanning calorimetry, X-ray diffraction, dissolution studies, and particle size analysis were performed to evaluate changes in nystatin crystallinity. Antifungal activity and anti-biofilm efficacy were assessed by microbiological techniques. The results for nystatin solid dispersions showed that the enhancement of antifungal activity may be related to the high proportions of maltodextrins. Anti-biofilm assays showed a significant reduction (more than 80%) on biofilm formation with SD-N:MD [1:6] compared to the nystatin reference suspension. The elaboration process and physicochemical properties of SD-N:MD [1:6] could be a promising strategy for treatment of Candida biofilms.

scholarly journals Functional Properties and Molecular Degradation of Schizostachyum Brachycladum Bamboo Cellulose Nanofibre in PLA-Chitosan Bionanocomposites

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2008
Author(s):  
Samsul Rizal ◽  
N. I. Saharudin ◽  
N. G. Olaiya ◽  
H. P. S. Abdul Khalil ◽  
M. K. Mohamad Haafiz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Moisture Content ◽  
Polymeric Materials ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Thickness Swelling ◽  
Compression Moulding ◽  
Ft Ir ◽  
Degradation Properties

The degradation and mechanical properties of potential polymeric materials used for green manufacturing are significant determinants. In this study, cellulose nanofibre was prepared from Schizostachyum brachycladum bamboo and used as reinforcement in the PLA/chitosan matrix using melt extrusion and compression moulding method. The cellulose nanofibre(CNF) was isolated using supercritical carbon dioxide and high-pressure homogenisation. The isolated CNF was characterised with transmission electron microscopy (TEM), FT-IR, zeta potential and particle size analysis. The mechanical, physical, and degradation properties of the resulting biocomposite were studied with moisture content, density, thickness swelling, tensile, flexural, scanning electron microscopy, thermogravimetry, and biodegradability analysis. The TEM, FT-IR, and particle size results showed successful isolation of cellulose nanofibre using this method. The result showed that the physical, mechanical, and degradation properties of PLA/chitosan/CNF biocomposite were significantly enhanced with cellulose nanofibre. The density, thickness swelling, and moisture content increased with the addition of CNF. Also, tensile strength and modulus; flexural strength and modulus increased; while the elongation reduced. The carbon residue from the thermal degradation and the glass transition temperature of the PLA/chitosan/CNF biocomposite was observed to increase with the addition of CNF. The result showed that the biocomposite has potential for green and sustainable industrial application.

Microstructure Evolution of a Fine Grain Al-50wt%Si Alloy Fabricated by High Energy Milling

2011 ◽  
Vol 479 ◽  
pp. 54-61 ◽  
Author(s):  
Fei Wang ◽  
Ya Ping Wang
Keyword(s):  
Grain Growth ◽  
Microstructure Evolution ◽  
Room Temperature ◽  
Milling Time ◽  
High Energy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Laser Method ◽  
X Ray ◽  
Fine Grain

Microstructure evolution of high energy milled Al-50wt%Si alloy during heat treatment at different temperature was studied. Scanning electron microscope (SEM) and X-ray diffraction (XRD) results show that the size of the alloy powders decreased with increasing milling time. The observable coarsening of Si particles was not seen below 730°C in the high energy milled alloy, whereas, for the alloy prepared by mixed Al and Si powders, the grain growth occurred at 660°C. The activation energy for the grain growth of Si particles in the high energy milled alloy was determined as about 244 kJ/mol by the differential scanning calorimetry (DSC) data analysis. The size of Si particles in the hot pressed Al-50wt%Si alloy prepared by high energy milled powders was 5-30 m at 700°C, which was significantly reduced compared to that of the original Si powders. Thermal diffusivity of the hot pressed Al-50wt%Si alloy was 55 mm2/s at room temperature which was obtained by laser method.

Preparation of Amorphous Nanosilica from Philippine Waste Rice Hull via Acid Precipitation Method

2016 ◽  
Vol 864 ◽  
pp. 112-116
Author(s):  
Rinlee Butch M. Cervera ◽  
Emie A. Salamangkit-Mirasol
Keyword(s):  
Electron Microscopy ◽  
Low Cost ◽  
Agricultural Waste ◽  
Acid Precipitation ◽  
Particle Size Analysis ◽  
Precipitation Method ◽  
Rice Hull ◽  
Size Analysis ◽  
Rice Hull Ash ◽  
Transmission Electron

Rice hull or rice husk (RH) is an agricultural waste obtained from milling rice grains. Since RH has no commercial value and is difficult to use in agriculture, its volume is often reduced through open field burning which is an environmental hazard. In this study, amorphous nanosilica from Philippine waste RH was prepared via acid precipitation method. The synthesized samples were fully characterized for its microstructural properties. X-ray diffraction pattern reveals that the structure of the prepared sample is amorphous in nature while Fourier transform infrared spectrum showed the different vibration bands of the synthesized sample. Scanning electron microscopy (SEM) and particle size analysis (PSA) confirmed the presence of agglomerated silica particles. On the other hand, transmission electron microscopy (TEM) revealed an amorphous sample with grain sizes of about 5 to 20 nanometer range and has about 95 % purity according to EDS analyses. The elemental mapping also suggests that leaching of rice hull ash effectively removed the metallic impurity such as potassium element in the material. Hence, amorphous nanosilica was successfully prepared via a low-cost acid precipitation method from Philippine waste rice hull.

scholarly journals Assessment of Physical, Microstructural, Thermal, Techno-Functional, And Rheological Characteristics of Apple (Malus Domestica) Seeds of Northern Himalayas

2021 ◽  
Author(s):  
Mehnaza Manzoor ◽  
Jagmohan Singh
Keyword(s):  
Energy Requirement ◽  
Geometric Mean ◽  
High Energy ◽  
Particle Size Analysis ◽  
Absorption Capacity ◽  
Size Analysis ◽  
Scanning Electron Micrographs ◽  
Seed Flour ◽  
Mean Diameter ◽  
Golden Delicious

Abstract The study examined the physical, morphological, thermal, techno-functional, and rheological properties of two apple seed cultivars viz: red delicious (RD) and golden delicious (GD). Physical properties showed that red delicious seeds were significantly (p≤0.05) different in width, geometric mean diameter, arithmetic mean diameter, volume, and surface area than golden delicious seeds. The proximate composition of RD seed flour showed a higher amount of crude protein and fat content than GD seed flour. RD seed flour was significantly different in L*, a*, b* values, bulk density, water/oil absorption capacity and the emulsifying ability than GD seed flour. From particle size analysis it was possible to found that GD was significantly (p≤0.05) lower than RD flour macromolecules. Scanning electron micrographs showed oval/spherical starch granules of small size embedded in a continuous protein matrix. Thermograph revealed exothermic transition enthalpy for both RD and GD seed flour, which indicates a high energy requirement for crystallite melting. The rheological assays revealed high elastic modulus (G′), of seed flours that will help in modifying the texture of foods. This study suggests the potential of apple seeds in the formulation of protein-enriched foods to combat malnutrition while contributing to the reduction in industrial wastage.

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