Laser-processing-induced phase transformation in Zn–Al-based alloy

1999 ◽  
Vol 14 (11) ◽  
pp. 4188-4194 ◽  
Author(s):  
Y. H. Zhu ◽  
J. A. Chavez-Carvayar ◽  
H. C. Man ◽  
M. Villagran
Keyword(s):  
Electron Microscopy ◽  
Phase Transformation ◽  
Laser Beam ◽  
Phase Transformations ◽  
Laser Processing ◽  
Thermomechanical Processing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Backscattered Scanning Electron Microscopy ◽  
Scanning Electron

Microstructure and phase transformation of a furnace-cooled eutectoid Zn–Al-based alloy were studied after laser beam bombardment using low-angle x-ray diffraction (XRD) and backscattered scanning electron microscopy (BSEM). It was found that the microstructure of the laser-beam-treated specimen consisted mainly of the supersaturated Zn-rich β′s phase particulates of about 1−2 μm in diameter. Three structure morphologies were observed. Microcracking occurred in the laserbeam-affected zone during laser processing. Two laser-processing-induced phase transformations, i.e., decomposition of the η′FC phase and a four-phase transformation, were detected using XRD and BSEM techniques, similar to phase transformations that occurred in the same eutectoid Zn–Al-based alloy after various thermal and thermomechanical processing procedures.

scholarly journals The Effect of Laser Beam Processing on the Properties of WC-Co Coatings Deposited on Steel

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 538
Author(s):  
Norbert Radek ◽  
Janusz Konstanty ◽  
Jacek Pietraszek ◽  
Łukasz Orman ◽  
Marcin Szczepaniak ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Laser Beam ◽  
Laser Processing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Protective Layers ◽  
Carbide Coatings ◽  
Steel Substrates ◽  
Roughness Measurements ◽  
Scanning Electron

The main objective of the present work is to determine the effects of laser processing on properties of WC-Co electro-spark deposited (ESD) coatings on steel substrates. Tungsten carbide coatings have been applied to steel substrates using a manual electrode feeder, model EIL-8A. The laser beam processing (LBP) of electro-spark coatings was performed using an Nd:YAG fiber laser. The microstructure and properties of laser treated/melted coatings were evaluated by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), surface geometric structure (SGS) and roughness measurements and adhesion, microhardness, residual stresses, corrosion resistance and application tests. The obtained experimental data were subjected to statistical analysis and multidimensional numerical and visual exploratory techniques. It has been shown conclusively that the laser-treated ESD WC-Co coatings are characterized by lower microhardness, higher resistance to corrosion, increased roughness and better adhesion to the substrate. LBP homogenizes the chemical composition, refines the microstructure and heals microcracks and pores of ESD coatings. The laser treated ESD WC-Co coatings can be used in frictional sliding nodes (e.g., on the front seal rings used in pumps) and as protective layers.

scholarly journals Effects of Calcination Temperatures on Photocatalytic Activity of Ordered Titanate Nanoribbon/SnO2Films Fabricated during an EPD Process

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Li Zhao ◽  
Jingrun Ran ◽  
Zhan Shu ◽  
Guotian Dai ◽  
Pengcheng Zhai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Transformation ◽  
Photocatalytic Activity ◽  
Charge Carriers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcination Temperatures ◽  
Fto Glass ◽  
Scanning Electron

Ordered titanate nanoribbon (TNR)/SnO2films were fabricated by electrophoretic deposition (EPD) process using hydrothermally prepared titanate nanoribbon as a precursor. The formation mechanism of ordered TNR film on the fluorine-doped SnO2coated (FTO) glass was investigated by scanning electron microscopy (SEM). The effects of calcination temperatures on the phase structure and photocatalytic activity of ordered TNR/SnO2films were investigated and discussed. The X-ray diffraction (XRD) results indicate that the phase transformation of titanate to anatase occurs at 400°C and with increasing calcination temperature, the crystallization of anatase increases. At 600°C, the nanoribbon morphology still hold and the TiO2/SnO2film exhibits the highest photocatalytic activity due to the good crystallization, unique morphology, and efficient photogenerated charge carriers separation and transfer at the interface of TiO2and SnO2.

STUDY OF HYDROTHERMAL SYNTHESIS AND PROPERTIES OF Bi2Fe4O9

2010 ◽  
Vol 03 (03) ◽  
pp. 173-176 ◽  
Author(s):  
YIBO WANG ◽  
HUAJUN SUN ◽  
JING ZHOU ◽  
BO LI ◽  
CHENGYONG ZHANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase Transformation ◽  
Dielectric Properties ◽  
X Ray Diffraction ◽  
Impedance Analyzer ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Highly oriented Bi2Fe4O9 nanosheets can be fabricated with Fe(NO3)3 ⋅ 9H2O and Bi(NO3)3 ⋅ 5H2O using the low-temperature hydrothermal method. The as-prepared powders are characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM), which exhibit an excellent orientation along the (00l) planes. The leakage current density and dielectric properties of the nanosheet samples are measured by Radiant Precision Workstation and HP4291B Impedance Analyzer, respectively. The effects of NaOH concentration on the phase transformation, sheet size and morphologies of the Bi2Fe4O9 crystallites are studied in this paper.

PHASE TRANSFORMATION AND MICROSTRUCTURE BEHAVIOUR OF CU-AL-NI SHAPE MEMORY ALLOYS INCORPORATED WITH COBALT ADDITION

2015 ◽  
Vol 74 (10) ◽  
Author(s):  
Y. C. Wee ◽  
T. Abubakar ◽  
E. Hamzah ◽  
Safaa N. Saud
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Transformation ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Transformation Temperatures ◽  
X Ray ◽  
Co Addition ◽  
Cobalt Addition ◽  
Scanning Electron

The effect of Co addition on phase transformation temperatures and microstructures of Cu-Al-Ni SMA were investigated via differential scanning calorimetry, field emission scanning electron microscopy corresponding with energy dispersive spectroscopy and x-ray diffraction. The results revealed that the β1’ and γ1’ phases’ morphology and orientation were varied after the addition of Co along with the presence of intermetallic compounds known as γ2. This phase was indicated using the EDS and XRD is related to the intermetallic compound of Al75Co22Ni3. In addition, the phase transformation temperatures tend to increase with the addition of Co and this enhancement is mainly attributed to the variation of phase morphology and the existence of γ2 precipitates. 

Synthesis and Decomposition of Ti3SiC2 under 1-5GPa at 1400°C

2014 ◽  
Vol 602-603 ◽  
pp. 499-502 ◽  
Author(s):  
Yuan Yuan Zhu ◽  
Shang Sheng Li ◽  
Liang Li ◽  
Ai Guo Zhou
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Pressure ◽  
Phase Transformation ◽  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ternary Carbide ◽  
Scanning Electron

Ternary carbide Ti3SiC2 is a good binder to make superhard composites with diamonds or cubic boron nitride. Superhard composites are normally made at high temperature and under high pressure around 5 GPa to avoid the phase transformation of diamonds or cubic boron nitride. This paper researched the synthesis of Ti3SiC2 from the powders of Ti, Si, and graphite by a cubic presser under 1 GPa to 4 GPa at 1400°C. The decomposition of Ti3SiC2 under 5GPa at 1400°C was also researched. From X-ray diffraction (XRD) and scanning electron microscopy (SEM) results, Ti3SiC2 was synthesized in 30 min under 1 GPa at 1400°C. The impurities were TiSi2, Ti5Si3Cx, and TiC. As the pressure increased from 1GPa to 4GPa, less Ti3SiC2 more TiSi2 was synthesized. Therefore, high presser > 1GPa is unfavorable for the synthesis of Ti3SiC2. After treated under 5GPa at 1400°C, pure Ti3SiC2 was decomposed.

Influence of CeO2 Additive on the Phase Transformations of Zirconia from Zircon Ore by Carbothermal Reduction Process

2014 ◽  
Vol 602-603 ◽  
pp. 238-241 ◽  
Author(s):  
Teng Yu Wang ◽  
You Guo Xu ◽  
Zhao Hui Huang ◽  
Ming Hao Fang ◽  
Yan Gai Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Transformations ◽  
Carbothermal Reduction ◽  
Heating Temperature ◽  
Reduction Process ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
X Ray ◽  
Additive Increase ◽  
Scanning Electron

This paper mainly discusses the influences of heating temperatures and CeO2 additive contents on the phase transformations of zirconia from zircon ore by carbothermal reduction. The phase transformations of zirconia from zircon ore by carbothermal reduction were monitored by X-ray diffraction. The microstructure of the product was characterized by scanning electron microscopy. The results show that without adding CeO2, the optimized heating temperature of zircon carbothermal reduction was 1600 °C and the main phases of the product were m-ZrO2, ZrC and β-SiC, t-ZrO2; After adding CeO2, the main phase of the products consists of t-ZrO2, m-ZrO2, ZrC and β-SiC when the heating temperature is 1600 °C. CeO2 additive can be introduced into zirconia lattice and can cause it to form cerium stabilized zirconia. Zirconia in the product would be turned into partially stabilized zirconia with cerium addition from 5 wt% to 20 wt%. However, the form of zirconia in the product is not changed greatly with the amount of CeO2 additive increase.

Preparation of β-TCP/HAP Composite Bioceramics

2007 ◽  
Vol 336-338 ◽  
pp. 1642-1645 ◽  
Author(s):  
Tong Jun Liu ◽  
De An Yang ◽  
Li Zhi Di
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Compressive Strength ◽  
Phase Transformation ◽  
Composite Ceramics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The β-TCP granules with the range of diameter from 314μm to 800μm were prepared. The β-TCP/HAP composite bioceramics were prepared by dipping β-TCP discs made from the granules in HAP sol. The component and morphology of the ceramics were observed by X-ray diffraction (XRD) and scanning electron microscopy (SEM) respectively. The compressive strength of specimens was tested by Testometric M350-20KN. The results show that the samples can be calcined at 1150°C without phase transformation of β-TCP to α-TCP by doping the β-TCP with 1wt% MgO. And the compressive strength of the composite ceramics reaches 24MPa.

scholarly journals Phase Transformation of Zeolite P to Y and Analcime Zeolites due to Changing the Time and Temperature

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Seyed Naser Azizi ◽  
Akram Alavi Daghigh ◽  
Maryam Abrishamkar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Phase Transformation ◽  
Hydrothermal Condition ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Template Free ◽  
Zeolite P ◽  
Scanning Electron

In the present study, the synthesis of template free zeolite P under hydrothermal condition was investigated. The effects of parameters such as Si/Al ratios (3–45), crystallization temperatures (80–160°C), and cry (40–60 h) on the synthesis of zeolite P were studied. The phase transformation of zeolite P to two types of high crystallinity Y and analcime zeolites due to change of temperature was observed. The effect of temperature on the achievement of two different zeolite types (Y and analcime) with a constant initial synthetic composition under organic free synthesis of zeolite P was studied. The zeolitic products were characterized by X-ray diffraction, scanning electron microscopy, and IR spectroscopy techniques.

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.

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