Microstructure of 7N01 Aluminum Alloy Microalloyed with Er and Zr in the Homogenization Process

2020 ◽  
Vol 993 ◽  
pp. 123-129
Author(s):  
Pei Hao Zhao ◽  
Xiao Lan Wu ◽  
Kun Yuan Gao ◽  
Yu Sheng Ding ◽  
Hui Huang ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Electron Microscope ◽  
Cast Alloy ◽  
Secondary Phase ◽  
Dendritic Segregation ◽  
Secondary Phases ◽  
Sem Images ◽  
Homogenization Process ◽  
Transmission Electron ◽  
Before And After

The microstructure and segregation of 7N01 aluminum alloy microalloyed with Er and Zr before and after homogenization process at 470 °C for 24 h have been investigated using transmission electron microscope (TEM), and scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscope (EDS) and transmission electron detecter (STEM). SEM images and EDS line scan results showed that there were dendritic segregation of Mg and Zn and micron-sized primary phases along dendrites in the as-cast alloy. The primary phases were mainly Al2Mg3Zn3 containing Al, Zn, Mg and Mn. And a small amount of primary phases were the particles containing Al, Zn, Mg, Mn, Cr and Er and the particles containing Al, Zn, Mg, Er, Mn, Fe and Cr. After homogenization at 470°C for 24 h, dendritic segregation of Mg and Zn was eliminated, Al2Mg3Zn3 and the particles containing Al, Zn, Mg and Mn were basically dissolved. The particles containing Al, Zn, Mg, Mn, Cr and Er and the particles containing Al, Zn, Mg, Er, Mn, Fe and Cr remained. Meanwhile, TEM and STEM images showed that a large number of secondary phases appeared after the homogenization, which were mainly distributed in the inter-dendrite area. EDS results showed that the block-shaped and rod-shaped phases with the width of 10-70 nm and length of 100-500 nm were the particles containing Al, Cr and Mn or Al, Mg, Cr and Mn, and the ellipsoid secondary phase with the size of 50-100 nm was MgZn2.

Neptunium-Doped Synroc: Partitioning, Leach Data and Secondary Phase Development

1995 ◽  
Vol 412 ◽  
Author(s):  
Katherine L. Smith ◽  
Mark G. Blackford ◽  
Gregory R. Lumpkin ◽  
Kaye P. Hart ◽  
Brett J. Robinson
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Transmission Electron Microscope ◽  
Secondary Phase ◽  
Secondary Phases ◽  
Phase Development ◽  
Transmission Electron ◽  
Total Differential ◽  
Scanning Electron

AbstractNp-doped Synroc was subjected to modified MCC-1 leach tests in demineralised water at 70°C. Normalised total differential Np leach rates were about 10−4 g m−2 d−1 initially, decreased to about 10−5 g m−2 d−1 after 60 days and stayed approximately constant for periods totalling up to 2283 d. Scanning electron microscope (SEM) and analytical transmission electron microscope (AEM) examination of discs leached for periods totalling 56 d or longer showed that they were covered with crystalline anatase, brookite and ilmenite. The crystalline secondary phases initially nucleated in polishing scratches and on perovskite grains. However, after leaching for a total of 422 d most of the surface was covered. None of the secondary phases contained observable amounts of Np (< 0.2 wt%). These data are discussed in relation to previous work.

An Electron Microscope Study of Interdiffusion and Compound Formation in Ta-Au Thin Films

1973 ◽  
Vol 31 ◽  
pp. 32-33 ◽  
Author(s):  
T. C. Tisone ◽  
S. Lau
Keyword(s):  
Electron Microscope ◽  
Electron Microscope Study ◽  
Thermally Grown Oxide ◽  
Ion Milling ◽  
Compound Formation ◽  
Technology Application ◽  
Transmission Electron ◽  
Before And After ◽  
Au Thin Films

In a study of the properties of a Ta-Au metallization system for thin film technology application, the interdiffusion between Ta(bcc)-Au, βTa-Au and Ta2M-Au films was studied. Considered here is a discussion of the use of the transmission electron microscope(TEM) in the identification of phases formed and characterization of the film microstructures before and after annealing.The films were deposited by sputtering onto silicon wafers with 5000 Å of thermally grown oxide. The film thicknesses were 2000 Å of Ta and 2000 Å of Au. Samples for TEM observation were prepared by ultrasonically cutting 3mm disks from the wafers. The disks were first chemically etched from the silicon side using a HNO3 :HF(19:5) solution followed by ion milling to perforation of the Au side.

scholarly journals Characterization of Precipitation in 7055 Aluminum Alloy by Laser Ultrasonics

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 275
Author(s):  
Zhenge Zhu ◽  
Hao Peng ◽  
Yacheng Xu ◽  
Xueyong Song ◽  
Jinrong Zuo ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Electron Microscope ◽  
Laser Ultrasonics ◽  
Precipitate Size ◽  
Destructive Testing ◽  
Laser Ultrasonic ◽  
Precipitated Phase ◽  
Transmission Electron ◽  
7055 Aluminum Alloy ◽  
The Time Domain

After different rolling conditions, four 7055 aluminum alloy samples with different precipitation sizes were measured by scanning electron microscope, transmission electron microscope and laser ultrasonic. The attenuation coefficients of ultrasound measured by laser ultrasonic were calculated in the time domain, frequency domain and wavelet denoising, respectively. The relationship between the precipitate size and attenuation coefficient was established. The results show that the attenuation of the ultrasonic wave is related to the size of the precipitated phase; this provides a new method for rapid non-destructive testing of the precipitation of aluminum alloys.

scholarly journals Fabrication of Mesostructured Silica and Titania Rods on Substrates by Using Polycarbonate Membranes

2010 ◽  
Vol 2010 ◽  
pp. 1-4 ◽  
Author(s):  
Norihiro Suzuki ◽  
Yusuke Yamauchi
Keyword(s):  
Electron Microscope ◽  
Longitudinal Axis ◽  
Sem Images ◽  
One Pot ◽  
Polycarbonate Membrane ◽  
Entire Area ◽  
Transmission Electron ◽  
Polycarbonate Membranes ◽  
Fibrous Morphology ◽  
Oriented Parallel

By using the polycarbonate membrane a template, mesoporous silica rods are fabricated on a silicon substrate in one pot. From scanning electron microscope (SEM) images, the creation of fibrous morphology is confirmed over the entire area. The diameter of the obtained rods is consistent with that of the template. Transmission electron microscope (TEM) images revealed that the tubular mesochannels are uniaxially oriented parallel to the longitudinal axis of the silica rods. The mesoporous titania rods with anatase crystalline frameworks are also fabricated.

Microstructural Characterization of an Al-Mg-Si Aluminum Alloy Processed by Equal Channel Angular Pressing

2013 ◽  
Vol 745-746 ◽  
pp. 303-308
Author(s):  
Zhen Zhang ◽  
Man Ping Liu ◽  
Ying Da Yu ◽  
Pål C. Skaret ◽  
Hans Jørgen Roven
Keyword(s):  
Aluminum Alloy ◽  
Electron Microscope ◽  
High Resolution ◽  
Dislocation Density ◽  
Equal Channel Angular Pressing ◽  
Transmission Electron Microscope ◽  
Microstructural Characterization ◽  
Dark Field ◽  
Angular Pressing ◽  
Transmission Electron

In the present work, a peak-aged 6061 Al-Mg-Si aluminum alloy was subjected to equal channel angular pressing (ECAP) at 110 °C. The microstructure of the sample was characterized by high-resolution transmission electron microscope and weak-beam dark-field method. It was shown that the dislocation density in some local areas is much lower than the average dislocation density expected in the usual alloys processed by severe plastic deformation. High-resolution transmission electron microscope observations indicated that many full dislocations were dissociated into partial dislocations connected by stacking faults. In addition, a Z-shaped defect (i.e., a type of dislocation locks) probably formed by the reactions of the partials in different {111} planes was first observed in the ECAPed alloy. Furthermore, the precipitation behavior and sequence in the present ECAPed sample were identified by high-resolution transmission electron microscopy.

Elaboration and characterization of novel polyamide-12-layered titanoniobates nanocomposites

2009 ◽  
Vol 24 (11) ◽  
pp. 3358-3371 ◽  
Author(s):  
Sophie Chausson ◽  
Richard Retoux ◽  
Jean-Michel Rueff ◽  
Loïc LE Pluart ◽  
Pierre-Jean Madec ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
Thermomechanical Properties ◽  
Polyamide 12 ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Before And After ◽  
Basic Reaction

This article describes the synthesis and the characterization of a polyamide-12 filled with a nanostructured organic/inorganic titanoniobate hybrid material. The pristine oxide KTiNbO5 has been successfully organomodified by N-alkyl amines via an acido-basic reaction after a cationic exchange step as shown by x-ray diffraction. Transmission electron microscope study and scanning transmission electron microscope observations have been used to describe the change of morphology of the nanofillers before and after processing; the micronic aggregates were changed into single sheets and dispersed in the polymer. Thermomechanical properties of the composites have been determined, and their analyses with structure-properties models are consistent with the exfoliation of the organomodified titanoniobates.

Microstructure and Creep Behaviors of As-Cast Mg-Zn-Er Alloys

2017 ◽  
Vol 898 ◽  
pp. 305-310
Author(s):  
Rui Jing Li ◽  
Shu Bo Li ◽  
Ke Liu ◽  
Zhao Hui Wang ◽  
Xian Du ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Creep Strain ◽  
Volume Fraction ◽  
Cast Alloy ◽  
Optical Microscope ◽  
Quasicrystalline Phase ◽  
X Ray Diffraction ◽  
Creep Tests ◽  
Transmission Electron ◽  
Icosahedral Quasicrystalline

The microstructure and creep behaviors of cast Mg-xZn-yEr (x=3,6,9 wt.%, x/y=6) alloys were investigated by X-ray diffraction (XRD), optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). XRD results indicated that the main phase compositions of as-cast Mg-xZn-yEr alloys were the icosahedral quasicrystalline phase (I-phase) and α-Mg solid solution. The I-phase mainly distributed in the dendritic and staccato strips. The creep tests were conducted under the condition of 448 K, 70 MPa for 100 h. As the addition of Er increased from 0.5 wt.% to 1.5 wt.%, the total creep strain decreased from 0.962% to 0.512%, and the steady state creep rate decreased from 1.411×10-8s-1 to 4.917×10-9s-1. The I-phase had a tendency to be bulky and continuous, as the volume fraction of Er element increased. Ascribed to the I-phase, the creep strain happened and effectively blocked the movement of dislocations, resulting in the strengthened as-cast Mg-Zn-Er alloys and improved creep resistance. Based on the investigation of creep behaviors, the creep mechanism of the as-cast alloy was mainly grain boundary slipping.

Liquid Infiltration of MgO and Al2O3 Thin Films

1993 ◽  
Vol 318 ◽  
Author(s):  
Michael P. Mallamaci ◽  
Sundar Ramamurthy ◽  
C. Barry Carter
Keyword(s):  
Thin Films ◽  
Electron Microscope ◽  
Grain Boundaries ◽  
Transmission Electron Microscope ◽  
Bulk Materials ◽  
Ceramic Substrates ◽  
Liquid Infiltration ◽  
Transmission Electron ◽  
Before And After ◽  
Novel Method

ABSTRACTThe deposition of glass films on thin ceramic substrates is a novel method for investigation of the initial stages of liquid infiltration into the grain boundaries of these materials. By maintaining electron transparency at all stages of the experiment, the transmission electron microscope (TEM) can be used to characterize individual grain boundaries before and after penetration by a liquid. The method has been tested for the MgO and AI2O3 systems, which have extensively studied experimental counterparts in which the corresponding bulk materials are infiltrated by a siliceous liquid.

Microstructure Evolution of Al-Zn-Mg-Cu Alloy with Erbium during Homogenization

2021 ◽  
Vol 1035 ◽  
pp. 253-258
Author(s):  
Zheng Jie Tian ◽  
Bo Long Li ◽  
Bo Hou Zhang ◽  
Peng Qi ◽  
Zuo Ren Nie
Keyword(s):  
Electron Microscope ◽  
Microstructure Evolution ◽  
Optical Microscope ◽  
Eutectic Phase ◽  
Two Stage ◽  
Dispersion Phase ◽  
Homogenization Process ◽  
Cu Alloy ◽  
Transmission Electron ◽  
Residual Al

The microstructure evolution of Al-Zn-Mg-Cu alloy with erbium was studied by optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) during homogenization process. The results showed that there were serious component segregation in the as-cast structure of the alloy, mainly composed of T(AlZnMgCu) , S(Al2CuMg) and a small amount of Al8Cu4Er and Al7Cu2Fe. The overheating temperature of the alloy was 482.5 °C. After homogenized at 470 °C for 24 h, the dissolution of T(AlZnMgCu) phase and S(Al2CuMg) phase reached to a balance, but the residual Al8Cu4Er phase could not be dissolved completely. Compared with single-stage homogenization, Al3(Er,Zr) dispersion phase with smaller grain size and more uniform distribution can be obtained after two stage homogenization process of 400 °C for 8 h followed by 470 °C for 24 h. By comparing the residue of non-equilibrium eutectic phase, two-stage homogenization is the best.

Research on Fabricating CVD Diamond Microstructures Using RIE Process

2009 ◽  
Vol 407-408 ◽  
pp. 41-44
Author(s):  
Wen Chen Chou ◽  
Choung Lii Chao ◽  
Wei Haw Fan ◽  
Kung Jeng Ma
Keyword(s):  
Electron Microscope ◽  
Aspect Ratio ◽  
High Hardness ◽  
Etching Time ◽  
Micro Structure ◽  
Transmission Electron ◽  
Chemical Inertness ◽  
Mask Material ◽  
Before And After ◽  
Afm Probe

Diamond is one of the most important engineering materials for its extreme hardness, high thermal conductivity value and chemical inertness. Due to its high hardness and strength, it can be ideal candidates for AFM probe or micro-needle. In this research, micro cone-like shaped diamond tips with high aspect ratio formed using reactive ion etching (RIE) method. The scanning electron microscope (SEM), transmission electron microscope (TEM) and micro-Raman spectroscopy were used to study the surface morphology and sub-surface micro-structure before and after RIE process. The results showed that gold could be adopted as mask material during the RIE process. Different microstructures could be obtained using different RIE parameters such as etch duration and reactant gas. After RIE (O2 50sccm, 200W) for 5min the micro cone-like structures (aspect ratio~8) could be observed on the surface if a thin layer of gold was applied as mask. However, under the same RIE conditions, the irregular pillar-like microstructures started to emerge if the etching time was stretched longer.

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