scholarly journals Evolución de la microestructura en aleaciones de acero inoxidable Fe-Cr preparadas por pulvimetalurgia

Respuestas ◽  
2016 ◽  
Vol 15 (2) ◽  
pp. 5-9
Author(s):  
Armando Sarmiento Santos
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Powder Metallurgy ◽  
Scanning Electron Microscope ◽  
Particle Size Distribution ◽  
Chromium Content ◽  
Density Variation ◽  
X Ray ◽  
Lower Porosity ◽  
Scanning Electron

Se estudia la influencia de los procesos utilizados durante las etapas de preparación de muestras por pulvimetalurgia, en algunas de las características de aleaciones inoxidables de Fe-Cr. Para ello se preparan muestras Fe-Cr con concentraciones de cromo entre 13,9 y 28,4 % en peso, se correlaciona el comportamiento de la variación de densidad de las muestras con su contenido de cromo y con los parámetros del proceso. Las muestras se someten a análisis elemental con la microsonda de rayos X acoplada al microscopio electrónico de barrido para corroborar los correspondientes contenidos de cromo. También fue observada la microestructura para las muestras con diferentes concentraciones de cromo. A partir de los análisis realizados se encontró una mayor densificación en las muestras con mayores contenidos de cromo, las cuales corresponden a una distribución de tamaño de partícula más ancha. Del estudio de la microestructura de las muestras, en función del contenido de cromo, se observa un mayor crecimiento de grano y menor porosidad en muestras con menor contenido de cromo.Palabras clave: pulvimetalurgia, aleaciones inoxidables, cromoAbstractThe influence of the processes used during the stages of sample preparation by powder metallurgy, in some of the characteristics of Fe-Cr stainless alloys, are studied. For this will prepared Fe-Cr samples with chromium concentrations between 13.9 and 28.4% by weight. The behavior of the density variation of samples with chromium content and process parameters were correlated. The samples were subjected to elemental analysis with X-ray microprobe coupled to a scanning electron microscope to confirm the relevant contents of chromium. Microstructure was also observed for samples with different chromium concentrations. From the analysis, we found a higher density in samples with higher chromium contents, which correspond to a wider particle size distribution. The study of samples microstructure, as a function of chromium content, reveals a higher grain growth and lower porosity in samples with lower chromium content. Keywords: powder metallurgy, stainless alloys, chromium

Comparison of Lini0.5Mn1.5O4 and LiMn2O4 for Lithium-Ion Battery

2013 ◽  
Vol 860-863 ◽  
pp. 956-959
Author(s):  
Xing Hua Liang ◽  
Lin Shi ◽  
Yu Si Liu ◽  
Tian Jiao Liu ◽  
Chao Chao Ye ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Electron Microscope ◽  
Solid State ◽  
Scanning Electron Microscope ◽  
Retention Rate ◽  
Lithium Ion ◽  
X Ray ◽  
Charge Discharge ◽  
Scanning Electron

The High Potential Material Lini0.5Mn1.5O4 was Synthesized via Solid-State Reaction.The Surface Morphology and Particle Size of the Sample were Observed by Scanning Electron Microscope(SEM).The Crystal Structure of the Sample was Collected and Analyzed through X-Ray Diffractometry(XRD).The Sample was Charaterized by Charge-Discharge Tests.Results Indicated that the Cycling Retention Rate was about 80%,after being Charge-Diacharged at a Rate of 0.1C in a Voltage of 3.45-4.77V for 10 Times.Compared with Limn2O4,LiNi0.5Mn1.5O4 has good cycle performance.Both of LiNi0.5Mn1.5O4 structure were space group of Fd3m.

Preparation and Characterisation of Amorphous Silica from Alkali Wastewater Produced in Manufacturing Process of ZrOCl2

2011 ◽  
Vol 194-196 ◽  
pp. 2164-2168 ◽  
Author(s):  
Bai Kun Wang ◽  
Hao Ding ◽  
Yun Xing Zheng ◽  
Ning Liang
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Amorphous Silica ◽  
Manufacturing Process ◽  
Zirconium Oxychloride ◽  
Silica Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The amorphous silica was prepared from the alkali wastewater rich in Na2O•nSiO2 produced in manufacturing process of zirconium oxychloride (ZrOCl2). The composition and microstructure of amorphous silica were studied by X-ray diffraction, X-ray fluorescence and scanning electron microscope, respectively. The results showed that the amorphous silica was mainly composed of uncrystallized substance, and the silica content was 96.4%. Its whiteness was 97.5% and the particle size was between 100nm and 200nm without agglomeration. The specific surface area of the amorphous silica was 531.9 m2/g, and its pore volume and diameter were 0.945 cm3/g and 4.94 nm, respectively.

scholarly journals Preparation and Characterization of White Carbon Black From Rice Husk

2017 ◽  
Vol 9 (2) ◽  
pp. 1-7 ◽  
Author(s):  
MAA Khan ◽  
MS Saha ◽  
S Sultana ◽  
AN Ahmed
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Carbon Black ◽  
Scanning Electron Microscope ◽  
Rice Husk ◽  
Chemical Properties ◽  
Acid Leaching ◽  
Amorphous Structure ◽  
X Ray ◽  
Scanning Electron

Generally white carbon black in a form of silica is used instead of carbon black as reinforcing filler for rubber compounding. In the present research white carbon black was prepared from rice husks in cost effective method with direct incineration of acid leaching rice husk. The physico-chemical properties of rice husk and the product of white carbon black obtained from rice husk were investigated by Thermogravimetry, Particle size analyzer, Scanning electron microscope; Fourier transformed infrared radiation (FTIR), X-ray fluorescence and X-ray difractometry analyses. It was found that the decomposition of organic constituents of rice husk was revealed by Thermo gravimetric and carbon, hydrogen, nitrogen, sulpher (CHNS) analyses. The FTIR spectrum showed presence of Si-O-Si band with a strong peak at 1085 cm-1. The analysis of particle size and scanning electron microscope demonstrated that the produced white carbon black represent different size of 112 ?m to 0.01 ?m with very small nano-particle and amorphous structure. The amorphous structure of product was also confirmed by XRD pattern. The high pure product as 99.9% was confirmed by XRF analysis. These types of product have potential application as filler in rubber compounding.J. Environ. Sci. & Natural Resources, 9(2): 1-7 2016

Study on Preparation of LiNi0.5Co0.2Mn0.3O2 Precursor-Spherical Ni0.5Co0.2Mn0.3O2(OH)2

2015 ◽  
Vol 816 ◽  
pp. 676-681 ◽  
Author(s):  
Xiao Long Qu ◽  
Zheng Fu Zhang ◽  
Jin Cheng ◽  
Xiao Yan Wang
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tap Density ◽  
Homogeneous Particle ◽  
Co Precipitation ◽  
Scanning Electron

The spherical Ni0.5Co0.2Mn0.3(OH)2 powders were prepared by ammonia-hydroxide co-precipitation method. The influence of different synthesizing factors on the precursors characteristic were investigated. The product prepared with optimized condition has tap density of D≥1.7g·cm-3, and middle particle size D50≈3.6μm. The X-ray diffraction (XRD) results showed that the precursor can be indexed by a hexagonal β-Ni (OH)2 structure. The scanning electron microscope (SEM) results showed that the powders had quasi-spherical pattern and homogeneous particle size distribution.

Study on the Phase Composition and Particle Size of Boron Mud

2014 ◽  
Vol 881-883 ◽  
pp. 1568-1571
Author(s):  
Zhi Qiang Ning ◽  
Ling Ling Zhang
Keyword(s):  
Particle Size ◽  
Phase Composition ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
X Ray ◽  
Laser Particle Size Analyzer ◽  
Particle Size Analyzer ◽  
Boron Mud ◽  
Scanning Electron

The phase composition and particle size of the boron mud is investigated by X-ray diffractometry (XRD), scanning electron microscope (SEM) and laser particle size analyzer. The mainly phase composition of the boron mud are magnesite (MgCO3) and forsterite (Mg2SiO4). The mainly phase composition of the calcined boron mud are forsterite (Mg2SiO4) and a small amount magnesia (MgO). the sizes of the boron mud are about 2~6μm and a few of them are bigger and less than 10μm and the particle size of less than 10μm is about 60%.

scholarly journals The particle size distribution (PSD) as criteria for comparison of silver powders obtained by different methods of synthesis and by conditions of electrolysis

2018 ◽  
Vol 54 (3) ◽  
pp. 291-300
Author(s):  
Lj. Avramovic ◽  
M. Bugarin ◽  
D. Milanovic ◽  
V. Conic ◽  
M.M. Pavlovic ◽  
...  
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Chemical Processes ◽  
The Third ◽  
Methods Of Synthesis ◽  
Current Densities ◽  
Scanning Electron

Silver powders produced by both electrochemical (galvanostatic (DC) and potentiostatic (POT) regimes of electrolysis) and chemical processes were examined by scanning electron microscope, and particle size distribution (PSD) of the obtained particles was done. In the DC regime, the current densities of ?14.4 mA cm-2 for the nitrate (NIT; powder denoted with DC(NIT)) and ?13.05 mA cm-2 for the ammonium (AM; DC(AM)) electrolytes were applied. In the POT regime, the used overpotentials were ?90 mV (NIT(90)) and ?150 mV (NIT(150)) for the nitrate, and ?625 mV (AM(625)) and ?925 mV (AM(925)) for the ammonium electrolytes. Reduction with hydrazine was used for chemical synthesis (powder denoted with HYD). On the basis of SEM and PSD analysis, Ag powders were grouped into three groups. In the first group DC(AM), AM(925) and HYD powders with the (8.4?8.9 %) volume ratios were placed. In the second group were AM(625) and DC(NIT) powders with the (6.5?6.6 %) volume ratios. NIT(90) and NIT(150) powders with the volume ratios of (5.2?5.7 %) made the third group. The obtained volume ratios were correlated with the morphology of synthesized particles in order to perceive advantages and lacks of powder production via electrochemical and chemical routes.

scholarly journals Determination of Particle Size Distribution of Used Black Tea Leaves by Scanning Electron Microscope

2013 ◽  
Vol 61 (1) ◽  
pp. 111-115 ◽  
Author(s):  
Mohammad Abul Hossain ◽  
Shigeru Mori
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Black Tea ◽  
Tea Leaves ◽  
Sem Images ◽  
Scanning Electron

The particle size distribution (PSD) of a particulate material is important in understanding its physical and chemical properties. Determination of PSD is essential in many physicochemical processes and production quality depends on the measurement and control of PSD. Scanning electron microscope (SEM), in addition to sieve analysis, has been used to determine the PSD of biomass materials like used black tea leaves (UBTL). Spherical, ellipsoidal and non-spherical particles of used black tea leaves were observed in SEM images. The PSD of four different sizes ranges of spherical and non spherical UBTL particles was determined from the measurement of SEM images of length wise and width wise diameters. The results enabled to determine the mean diameter or representative diameters of particles of wide size ranges. Dhaka Univ. J. Sci. 61(1): 111-115, 2013 (January) DOI: http://dx.doi.org/10.3329/dujs.v61i1.15106

Preparation of Nanosilica Powder Using Rice Husk via Precipitation Method

2020 ◽  
Vol 1010 ◽  
pp. 501-507
Author(s):  
Farah Diana Mohd Daud ◽  
Nur Aishah M. Azmy ◽  
Mudrikah Sofia Mahmud ◽  
Norshahida Sariffudin ◽  
Hafizah Hanim Mohd Zaki
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Thermal Treatment ◽  
Scanning Electron Microscope ◽  
Rice Husk ◽  
Acid Leaching ◽  
Precipitation Method ◽  
X Ray ◽  
Mean Particle Size ◽  
Scanning Electron

Silica in nanoscale has various superior properties which leads to a wide range of applications. Most researches used and metal alkoxides as the sources but very few researches attempted at preparing nanosilica powder from the agricultural waste which environmental friendly and inexpensive. This research is presented as the studies of optimization of parameters involved during preparation, aimed to improve the purity of silica produced. In this work, rice husk ash (RHA) precursor was subjected to precipitation method in order to produce nanosilica powder. Acid leaching and thermal treatment were done as a pre-synthesis process. The process parameters that have been studied were the refluxed NaOH concentration, heating time, and temperature, in which the properties were then evaluated during characterization process. The results from X-Ray Flourescence (XRF) confirmed that it is possible to extract 100% purity of silica from RHA treated by the combination of thermal treatment, acid leaching, refluxed with 2.5 M of NaOH and heated at 50°C for 48 hours. X-Ray Diffraction (XRD) illustrated that the produced silica is in amorphous state. Meanwhile, the mean particle size of the spherical shape of silica obtained ranging from 44.7 nm to 1.23 μm. Therefore, the best mean particle size obtained was by using the sample refluxed with 2.5 M NaOH and heated at 50°C for 48 hours, which were confirmed by Scanning Electron Microscope (SEM) and Field Emission Scanning Electron Microscope (FESEM). These findings on the optimum parameters indicate the successful production of highest purity of nanosilica powder with nanoscaled particle size.

X-ray micro tomography in the scanning electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 106-107 ◽  
Author(s):  
W. Brünger
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Target Surface ◽  
The Body ◽  
X Rays ◽  
Cross Sectional ◽  
X Ray ◽  
Micro Tomography ◽  
Scanning Electron

Reconstructive tomography is a new technique in diagnostic radiology for imaging cross-sectional planes of the human body /1/. A collimated beam of X-rays is scanned through a thin slice of the body and the transmitted intensity is recorded by a detector giving a linear shadow graph or projection (see fig. 1). Many of these projections at different angles are used to reconstruct the body-layer, usually with the aid of a computer. The picture element size of present tomographic scanners is approximately 1.1 mm2.Micro tomography can be realized using the very fine X-ray source generated by the focused electron beam of a scanning electron microscope (see fig. 2). The translation of the X-ray source is done by a line scan of the electron beam on a polished target surface /2/. Projections at different angles are produced by rotating the object.During the registration of a single scan the electron beam is deflected in one direction only, while both deflections are operating in the display tube.

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