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Preparation and Characterization of Magnetic Metal-Organic Framework Nanocomposites
Published in Anish Khan, Mohammad Jawaid, Abdullah Mohammed Ahmed Asiri, Wei Ni, Mohammed Muzibur Rahman, Metal-Organic Framework Nanocomposites, 2020
Afzal Ansari, Vasi Uddin Siddiqui, Weqar Ahmad Siddiqi
The SEM technique produces high-resolution two-dimensional (2D) images that are routinely used for MOFs characterization. It displays the shape of the material and its spatial variations, revealing information about external morphology, dispersion, and mixing of phases. The porous structure exhibited by the MOFs gives rise to particles of curious shapes such as cubes, bars, rhombohedral, and yields a diverse morphology (Figure 10.7a). SEM characterization usually requires gold or platinum for the coating of the surface with a conductive material based on the insulating nature of MOFs. The equipment works with a field emission gun that provides a highly focused electron beam, which increases the spatial resolution working at low potentials. This characteristic prevents damage by reducing the charging effect on the insulating material that the electron beam may induce in some sensitive MOFs [37,38].
High spatial resolution EDX microanalysis of III–V semiconducting materials
Published in A G Cullis, P D Augustus, Microscopy of Semiconducting Materials, 1987, 2021
J F Bullock, C J Humphreys, A G Norman, J M Titchmarsh
The use of a field emission gun and its associated high current density brings with it the possibility of specimen damage. A number of inorganic materials, notably oxides and halides (Humphreys et al 1985) have been shown to damage under the beam, to the extent of holes being produced in the specimen. Little work, however, has yet been done on the possibility of beam damage in III–V materials.
Effectiveness of MPCMS on Straight, Dimple-cavity & Rib-groove microchannel heat sinks – a comparative study
Published in Experimental Heat Transfer, 2022
John Peter R, K R Balasubramanian, Divakar s, Jinshah B s
The core phase change material used in this experiment was paraffin, with the monomers TEOS (Tetraethyl orthosilicate) and TNBT (Tetra-n-butyl titanate). CTAB (Cetyltrimethylammonium bromide) and n-Amyl alcohol were used as a surfactant and co-surfactant, respectively, and the ammonia solution was used to precipitate the reaction and ethanol was used as a solvent. All chemical reagents of analytical grade were purchased from Thermo-Fisher Scientific and used without further purification. De-ionized water with a resistivity of 18.2 MΩ-cm was utilized throughout the experiment. For microscopic characterization, a Field Emission Gun-based High-Resolution Scanning Electron Microscope (HRSEM) was used. The phase transition temperature and latent heat of the MPCM were measured using a differential scanning calorimeter [Perkin Elmer DSC6000].
Sintering anisotropy of binder jetted 316L stainless steel: part II – microstructure evolution during sintering
Published in Powder Metallurgy, 2022
Alberto Cabo Rios, Eduard Hryha, Eugene Olevsky, Peter Harlin
A scanning electron microscope Zeiss Leo Gemini 1550 with a field emission gun (FEGSEM) was used for microstructure characterisation. Grains with different lattice structures were identified by the electron backscattered diffraction (EBSD) technique and data were postprocessed by using open-source MTEX code [24]. All EBSD measurements were performed with a step size of 0.5 μm and an acceleration voltage of 20 kV. The acquired phase maps were processed after the acquisition, i.e. minor noise reduction was applied. High angle grain boundaries (twin boundaries) were defined by a misorientation of ∼60° and are illustrated by white lines in the resulting maps. The misorientation value of ∼60° found for the twin boundaries is typical for annealed 316L stainless steels [25]. Non-indexed data were related to the porous areas and is illustrated by black coloured areas in the resulting maps.
Improved Titanium Transfer in Submerged Arc Welding of Carbon Steel through Aluminum Addition
Published in Mineral Processing and Extractive Metallurgy Review, 2022
Theresa Coetsee, Frederik Johannes De Bruin
Welding experiments were conducted with and without metal powders (Al and Ti) to illustrate the process concept of oxygen potential control at the molten flux-weld pool interface. SAW welding tests were made as bead-on-plate runs onto steel plates of 350 mm length, 12 mm plate thickness and 300 mm plate width. Weld heat input was 2.0 kJ/mm (500 A, 28 V, 42 cm/minute) welded DCEP (Direct Current Electrode Positive) with 3.2 mm diameter wire. Structural steel grade EN 10025–2 was used as base plate material. The weld wire major element levels are from the supplier’s specification sheet as supplied by Afrox Ltd., South-Africa. The rest of the element analyses in Table 1 were obtained from laboratory analyses. The base plate steel was analyzed by optical emission spectroscopy (OES). The oxygen content in the base plate and weld wire was analyzed by combustion method. The welded plate was sectioned to remove cross section samples of the weld metal for major element analyses by OES, and total oxygen content analyses by combustion method. A Zeiss crossbeam 540 FEG (Field emission gun) SEM (Scanning electron microscope) was used in this study. EDS (energy dispersive spectrometer) analyses were done at 20 kV and 5.6 mm working distance. Commercial agglomerated flux of composition in Table 2 was used in the welding experiments. This is an Aluminate Basic flux (Basicity Index (BI) = 1.4) and was extensively analyzed as reported previously (Coetsee 2020). Al of (99.7% Al) as supplied by Sigma-Aldrich, and Ti of (99.5% Ti) as supplied by PLS Technik GmbH & Co. were used.