scholarly journals Enhancing the Oxidation Resistance of Al2O3-SiC-C Castables via Introducing Micronized Andalusite

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4775 ◽  
Author(s):  
Xiaoyu Wang ◽  
Saixin Wang ◽  
Yuandong Mu ◽  
Ruijie Zhao ◽  
Qingfeng Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Oxygen Diffusion ◽  
Area Ratio ◽  
Modulus Of Rupture ◽  
Thermal Shock Test ◽  
X Ray Diffraction ◽  
Shock Test ◽  
X Ray ◽  
The Matrix ◽  
Scanning Electron

Additions of andalusite aggregates (19 wt%) were shown in previous literature to enhance the antioxidation of Al2O3-SiC-C (ASC) castables. This work aims to investigate whether micronized andalusite has a greater influence on antioxidation improvement than andalusite aggregates. Various low contents (5 wt% and below) of micronized andalusite (≤5 μm) were introduced as a substitute for brown fused alumina in the matrix of ASC castables. The antioxidation of castable specimens was estimated by the oxidized area ratio on the fracture surface after a thermal shock test. The microstructure and phases of micronized andalusite and the castable specimens were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The results suggest that the antioxidation effects of ASC castables with a low addition of micronized andalusite are effectively enhanced. The heat-induced transformation of andalusite produces SiO2-rich glass, favoring the sintering of the castable matrix and impeding oxygen diffusion into the castable’s interior. Therefore, the castable antioxidation is enhanced without deteriorating the hot modulus of rupture.

Characteristics of Ni–Cr–Fe laser clad layers on EA4T steel

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744031
Author(s):  
Wenjing Chen ◽  
Hui Chen ◽  
Yongjing Wang ◽  
Congchen Li ◽  
Xiaoli Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cladding Layer ◽  
Metallurgical Bonding ◽  
The Matrix ◽  
Feeding Speed ◽  
Upper Bainite ◽  
Scanning Electron

The Ni–Cr–Fe metal powder was deposited on EA4T steel by laser cladding technology. The microstructure and chemical composition of the cladding layer were analyzed by optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The bonding ability between the cladding layer and the matrix was measured. The results showed that the bonding between the cladding layer and the EA4T steel was metallurgical bonding. The microstructure of cladding layer was composed of planar crystals, columnar crystals and dendrite, which consisted of Cr2Ni3, [Formula: see text] phase, M[Formula: see text]C6 and Ni3B phases. When the powder feeding speed reached 4 g/min, the upper bainite occurred in the heat affected zone (HAZ). Moreover, the tensile strength of the joint increased, while the yield strength and the ductility decreased.

Fabrication of TiAl/Ti2AlC Composite by Reaction Hot Pressing

2011 ◽  
Vol 52-54 ◽  
pp. 842-845 ◽  
Author(s):  
Jian Feng Zhu ◽  
Wen Wen Yang ◽  
Yi Ping Gong
Keyword(s):  
Electron Microscopy ◽  
Reaction Process ◽  
Hot Press ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Composite ◽  
The Matrix ◽  
Morphology Characteristics ◽  
Scanning Electron

TiAl/Ti2AlC in situ composite was successfully fabricated by hot-press-assisted reaction process from the mixture of Ti, Al and carbon black. The phase formation and transformation were investigated in detail by X-ray diffraction (XRD) and the morphology characteristics were also studied by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The results show that when the mixed powders were hot pressed at 1300 °C for 1 h, full dense and highly pure TiAl/Ti2AlC composite was synthesized. The TiAl was the matrix phase and the in situ synthesized Ti2AlC was reinforcing phase. The reaction process was also discussed.

Metallography, Microanalysis & Corrosion of the Athlit Ram

2011 ◽  
Vol 1319 ◽  
Author(s):  
M. R. Notis ◽  
M. Hoban ◽  
D-N. Wang
Keyword(s):  
Electron Microscopy ◽  
Cell Walls ◽  
Optical Metallography ◽  
Metal Corrosion ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Matrix ◽  
Wood Analysis ◽  
Maritime Museum ◽  
Scanning Electron

ABSTRACTThe Athlit ram, a bronze warship ram from a 2nd Century BCE Roman-era galley, was found in 1980 off the coast of Israel at Athlit, and is now displayed at the National Maritime Museum, Haifa, Israel. It meant to fit on the prow of a medium-sized oared warship. This ram is the only known surviving example of this ancient naval weapon. Inside the bronze ram some of the ship’s wood is still preserved. We have recently studied a piece of the ram removed during early conservation. Remnant metal, corrosion products, and mineralized and pseudomorphed wood have all been found and examined by light optical metallography, x-ray diffraction, scanning electron microscopy, and microanalysis using energy dispersive x-ray mapping. The main corrosion product on the Athlit Ram is identified as covellite (CuS), and the entrained material is pseudomorphed cedar wood. Analysis indicates the lumen to be replaced by calcium carbonate and the cell walls to be replaced by covellite, consistent with the matrix.

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.

Effect of Nd Addition on Microstructure of Mg-Zn-Nd Master Alloys

2012 ◽  
Vol 500 ◽  
pp. 646-650 ◽  
Author(s):  
Zhen Wei Zhao ◽  
Xin Ying Teng ◽  
Guo Rong Zhou
Keyword(s):  
Electron Microscopy ◽  
Growth Process ◽  
Energy Dispersive Spectrometer ◽  
X Ray Diffraction ◽  
Growth Morphology ◽  
X Ray ◽  
Nd Addition ◽  
Master Alloys ◽  
The Matrix ◽  
Scanning Electron

Mg-Zn-Nd master alloys containing spherical quasicrystal phase were prepared under conventional casting conditions. The microstructures and phases of Mg-Zn-Nd ternary alloy have been investigated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). The results show that the microstructure of Mg-Zn-Nd master alloys has been changed significantly with the addition of Nd. When adding 5wt% Nd, it is clear that a lot of spherical I-phase with high roundness and size below 10μm distributed evenly in the matrix. With the increase of Nd, the number of spherical I-phases is reduced and rod-like phases increased. The growth process and the final growth morphology of quasicrystal phase are restricted by the element Nd, thus the growth rates of all quasicrystal growth surfaces tend to be consistent, which contributes to the formation of spherical quasicrystal phase.

scholarly journals Influence of Lithium on Nanosized Films of Fe2O3

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
A. Turković ◽  
M. Ivanda ◽  
M. Bitenc ◽  
Z. Crnjak Orel
Keyword(s):  
Electron Microscopy ◽  
Morphological Changes ◽  
X Ray Diffraction ◽  
Metal Oxide Films ◽  
X Ray ◽  
Structural And Electrical Properties ◽  
The Matrix ◽  
The Impact ◽  
Nanosized Films ◽  
Scanning Electron

We have investigated nanosized thin films ofα-Fe2O3(hematite) andα-Fe2O3with addition of Li, by the impedance spectroscopy (IS), the Raman spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD). Combining all of these methods, and earlier obtained thermally stimulated currents (TSC) on the same samples, the dependence of structural and electrical properties upon percentage of Li added into the matrix of these metal-oxide films was found. The comparison of IS, Raman, SEM, XRD, and TSC results reveals the increase of the size of nanoparticles upon inducing 1% of Li inFe2O3matrix followed by the decrease of the size of nanoparticles in the case of samples with 10% Li, as well as the decrease (increase) of conductivity, respectively. These changes are explained by the structural and morphological changes caused by the impact ofLi+ions in the charge transfers. This material is suitable for application in the galvanic cell of second generation that could be used as solar-cells backup.

Effects of Magnesia Fines on Physical Properties of Al2O3-MgO Unfired Bricks

2013 ◽  
Vol 750-752 ◽  
pp. 554-557
Author(s):  
Jun Cong Wei ◽  
Sen Sen Niu ◽  
Yi Long Wang ◽  
Wei Ping Ma ◽  
Jun Bo Tu
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Bulk Density ◽  
Modulus Of Rupture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Strength Change ◽  
Magnesia Content ◽  
Increased Strength ◽  
Scanning Electron

Al2O3-MgO unfired bricks were prepared by using brown corundum, white corundum, fused magnesia and α-A12O3 micropowder as main starting materials, Al2O3-SiO2 gel powder as a binder. The effects of magnesia fines addition on physical performance of Al2O3-MgO unfired bricks were investigated. The phase composition and microstructure were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS). The results showed that with the increase of magnesia fines addition, bulk density of Al2O3-MgO unfired bricks after dried decreased and strength increased. After heat treatment at 1100 °C, apparent porosity (AP) slightly reduced, bulk density (BD) slightly increased. Strength had little change. After heat treatment at 1500 °C, AP first decreased and then increased, and strength change correspondingly. The hot modulus of rupture (HMOR) first increased and then decreased with increasing magnesia content. The optimum magnesia addition is at 6.0 wt. %.

scholarly journals Magnetic nanowires (Fe, Fe-Co, Fe-Ni) – magnetic moment reorientation in respect of wires composition

Nukleonika ◽  
2015 ◽  
Vol 60 (1) ◽  
pp. 63-67 ◽  
Author(s):  
Beata Kalska-Szostko ◽  
Urszula Wykowska ◽  
Dariusz Satuła
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Strong Dependence ◽  
Magnetic Nanowires ◽  
Deposition Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ni Alloy ◽  
The Matrix ◽  
Scanning Electron

Abstract Magnetic nanowires of Fe, Fe-Co, and Fe-Ni alloy and layered structure were prepared by electrochemical alternating current (AC) deposition method. The morphology of the nanowires in and without the matrix was studied by energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and X-ray diffraction (XRD), respectively. The wires either show strong dependence on the combination of elements deposition (alloy or layered) or chemical composition (Co or Ni). The magnetic properties of the nanostructures were determined on the basis of Mössbauer spectroscopy (MS).

Effect of Ca on Microstructure and Properties of Mg-Al-Si Alloys

2011 ◽  
Vol 194-196 ◽  
pp. 1369-1373 ◽  
Author(s):  
Chun Xiang Xu ◽  
Hui Ju ◽  
Yang Zhou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Chinese Script ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ca Addition ◽  
The Matrix ◽  
Morphology Modification ◽  
Scanning Electron

Effect of Ca addition on the morphology modification in Mg-7Al-0.8Zn-0.2Mn-1Si (AS71) alloys has been investigated using X-ray diffraction (XRD), optical microscopy (OM), and scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and various testing machines. The results show that when adding 0.1 wt% Ca, a small fraction of Mg2Si change from Chinese script type to polygonal type; with the Ca addition up to 0.3 wt%, edges and angles of polygonal type Mg2Si phase are changed; further increase in Ca addition, the morphology of Mg2Si is changed to strip-like or spot-like one. Meanwhile, the addition of Ca results in the morphology of β- Mg17Al12 phase changing from discontinuous net-like to dispersive island-like. Ca exists as solid-soluting atomic in the matrix with small Ca addition while in the form of CaSi2 with large Ca addition. Optimal mechanical properties can be achieved when Ca addition is 0.3 wt%.

Development and Evaluation of Mechanical Properties of Al/Ilmenite Nanocomposite

2014 ◽  
Vol 704 ◽  
pp. 32-38
Author(s):  
Lanka Rasidhar ◽  
A. Rama Krishna ◽  
Ch. Srinivasa Rao ◽  
K. Vijaya Lakshmi
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Secondary Phase ◽  
Stir Casting ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Matrix ◽  
Scanning Electron

In the present investigation, microstructure and mechanical properties of nanocomposites fabricated via stir casting were evaluated. The composites were based on Al (99.7) reinforced with ilmenite nanoparticles. The characterization of the nanoparticles and nanocomposites was investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) facilities. Microstructure of specimens show that reasonable distribution of FeTiO3 nanoparticles in the matrix, secondary phase FeAl3 observed in the microstructure. Ultimate tensile strength and compression tests were carried out in order to identify the mechanical properties. The hardness of the composites is enhanced with the addition of nanoparticles. The optimum value for ultimate tensile and compression strength are obtained with the addition of 3 % ilmenite nanoparticles. Ductile fracture in tensile fractured samples was observed by fractrography examination.

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