scholarly journals Effect of Aging Time on Crushing Performance of Al-0.5Mg-0.4Si Alloy for Safety Components of Automobile

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 608
Author(s):  
Jinkun Lu ◽  
Haichun Jiang ◽  
Lingying Ye ◽  
Daxiang Sun ◽  
Yong Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Tensile Test ◽  
Aging Time ◽  
Uniform Elongation ◽  
Total Elongation ◽  
Localized Deformation ◽  
Ductility Index ◽  
Transmission Electron ◽  
The Difference

The effect of aging time on the crushing performance of Al-0.5Mg-0.4Si alloy used for safety components of automobile was investigated by tensile test and crush test. Moreover, the microstructure of the alloy was investigated by transmission electron microscopy (TEM). The results show that the localized deformation ductility index, ΔAabs, which is defined as the difference between total elongation and uniform elongation, of Al-0.5Mg-0.4Si alloy is 6.5%, 7.0% and 8.5%, respectively, after being aged at 210 °C for 1, 3 and 6 h, and this tendency is the same as that of the crushing performance. The spacing of grain boundary precipitates (GBPs) from TEM results are found to be 94.9, 193.6 and 408.2 nm after being aged at 210 °C for 1, 3 and 6 h, respectively, and this tendency is same to that of ΔAabs. A mechanism about the relation between the spacing of GBPs and the ductility index ΔAabs has been proposed based on localized deformation around GBPs. With the increase of GBPs spacing, the ΔAabs increases, and the crushing performance is improved.

Influence of doping on crystal growth, structure and optical properties of nanocrystalline CaTiO3: a case study using small-angle neutron scattering

2015 ◽  
Vol 48 (3) ◽  
pp. 836-843 ◽  
Author(s):  
Oindrila Mondal ◽  
Manisha Pal ◽  
Ripandeep Singh ◽  
Debasis Sen ◽  
Subhasish Mazumder ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Optical Properties ◽  
Crystal Growth ◽  
Small Angle Neutron Scattering ◽  
Ionic Radius ◽  
Ionic Radii ◽  
Growth Structure ◽  
Transmission Electron ◽  
The Difference

The effect of dopant size (ionic radius) on the crystal growth, structure and optical properties of nanocrystalline calcium titanate, CaTiO3(CTO), have been studied using small-angle neutron scattering. X-ray diffraction, along with high-resolution transmission electron microscopy, confirms the growth of pure nanocrystalline CTO. Rietveld analysis reveals that the difference of ionic radii between dopant and host ions induces strain within the lattice, which significantly affects the lattice parameters. The induced strain, due to the difference of ionic radii, causes the shrinkage of the optical band gap, which is manifested by the redshift of the absorbance band. Mesoscopic structural analysis using scattering techniques demonstrates that the ionic radius of the dopant influences the agglomeration behaviour and particle size. A high-resolution transmission electron microscopy study reconfirms the formation of pure highly crystalline CTO nanoparticles.

Discrete angle rotations of Bi nanoparticles embedded in a Ga matrix

Open Physics ◽  
2010 ◽  
Vol 8 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Avraham Be’er ◽  
Richard Kofman ◽  
Yossi Lereah
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Time Resolved ◽  
Transmission Electron ◽  
The Difference ◽  
First Time ◽  
Microscopy Images ◽  
Bi Nanoparticles

AbstractSpontaneous instabilities of nanoparticles are known to be influenced by the temperature, and strongly depend on the particle size. However, it is not clear what is the role of the surrounding material that is in contact with the particle. Here we report on the difference between spontaneous rotations of Bi nanoparticles embedded in amorphous SiO and those embedded in liquid Ga. The phenomenon was studied quantitatively by time resolved transmission electron microscopy using Fourier Transform analysis of highresolution electron microscopy images. While rotations of Bi nanoparticles embedded in amorphous SiO occur by all angles, the rotations of Bi nanoparticles embedded in liquid Ga occur by discrete angles. Our results point quantitatively, for the first time, to the role and importance of the contacting surrounding surface during the rotation of nanoparticles.

DIRECT MEASUREMENTS OF SURFACE STRESS USING TRANSMISSION ELECTRON MICROSCOPY

1997 ◽  
Vol 04 (02) ◽  
pp. 245-269 ◽  
Author(s):  
R. D. TWESTEN ◽  
J. M. GIBSON ◽  
O. C. HELLMAN
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Surface Stress ◽  
Metastable Phase ◽  
Strain Fields ◽  
Imaging Parameters ◽  
Transmission Electron ◽  
Direct Measurements ◽  
The Difference ◽  
Image Simulations

Surface stress and energy are concepts which are often misunderstood. In this work, we will clarify the difference between the two. We describe the use of transmission electron microscopy to measure surface stress by quantitative analysis of strain contrast images. We find that images of surface-stress-induced strain fields can be used to measure quantitative differences in surface stress provided the imaging parameters are accurately determined. We have applied this method to measure the stress difference between the 7×7 and high temperature "1×1" phases of the Si(111) surface at the phase coexistence temperature and between metastable phase boundaries on the Si(111) and amorphous-Ge interface. We discuss the significance of these measurements and pitfalls to be avoided in image simulations.

scholarly journals Correlation between Taylor Model Prediction and Transmission Electron Microscopy-Based Microstructural Investigations of Quasi-In Situ Tensile Deformation of Additively Manufactured FeCo Alloy

2021 ◽  
Author(s):  
Sudipta Pramanik ◽  
Lennart Tasche ◽  
Kay-Peter Hoyer ◽  
Mirko Schaper
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Tensile Test ◽  
Deformation Behavior ◽  
Dislocation Cell ◽  
Taylor Model ◽  
Feco Alloy ◽  
Transmission Electron ◽  
Before And After ◽  
Active Slip

AbstractWithin this research, the multiscale microstructural evolution before and after the tensile test of a FeCo alloy is addressed. X-ray µ-computer tomography (CT), electron backscattered diffraction (EBSD), and transmission electron microscopy (TEM) are employed to determine the microstructure on different length scales. Microstructural evolution is studied by performing EBSD of the same area before and after the tensile test. As a result, $$\langle$$ ⟨ 001$$\rangle$$ ⟩ ||TD, $$\langle$$ ⟨ 011$$\rangle$$ ⟩ ||TD are hard orientations and $$\langle$$ ⟨ 111$$\rangle$$ ⟩ ||TD is soft orientations for deformation accommodation. It is not possible to predict the deformation of a single grain with the Taylor model. However, the Taylor model accurately predicts the orientation of all grains after deformation. {123}$$\langle$$ ⟨ 111$$\rangle$$ ⟩ is the most active slip system, and {112}$$\langle$$ ⟨ 111$$\rangle$$ ⟩ is the least active slip system. Both EBSD micrographs show grain subdivision after tensile testing. TEM images show the formation of dislocation cells. Correlative HRTEM images show unresolved lattice fringes at dislocation cell boundaries, whereas resolved lattice fringes are observed at dislocation cell interior. Since Schmid’s law is unable to predict the deformation behavior of grains, the boundary slip transmission accurately predicts the grain deformation behavior.

Role of Interface Boundaries in the Deformation Behavior of TiAl Polysynthetically Twinned Crystal: In situ Transmission Electron Microscopy Deformation Study

2005 ◽  
Vol 20 (7) ◽  
pp. 1888-1901 ◽  
Author(s):  
Sung G. Pyo ◽  
Nack J. Kim
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Deformation Behavior ◽  
Localized Deformation ◽  
Deformation Twins ◽  
Thin Foils ◽  
Transmission Electron ◽  
Longitudinal Orientation

To understand the role of boundaries in the deformation behavior of TiAl, in situ straining experiments in transmission electron microscopy have been performed on thin foils of polysynthetically twinned (PST) crystal of Ti–49.3 at.% Al. The deformation behavior of PST TiAl is anisotropic, depending on the angle between the lamellar boundaries and the straining axes. For L-orientation, deformation twins and ordinary dislocations transmit across the true-twin (TT) boundaries but are reflected at the pseudo-twin (PT) and rotational order-fault (RO) boundaries. For transverse (T) orientation, deformation twins are transmitted across all TT, PT, and RO boundaries. For I-orientation, shear deformation occurs parallel to the lamellar boundaries. There is a transmission of deformation across the interphase (IP) boundary in longitudinal orientation, but deformation is blocked and reflected at the IP boundary in T-orientation. The role of the various types of boundaries in localized deformation behavior was evaluated by considering Schmid factors and geometric compatibility factors.

Structural Characterization of Prismatic Stacking Faults of Two Types of Carrot Defects in 4H-SiC Epi Wafers

2020 ◽  
Vol 1004 ◽  
pp. 421-426
Author(s):  
Hideki Sako ◽  
Kentaro Ohira ◽  
Kenji Kobayashi ◽  
Toshiyuki Isshiki
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stacking Faults ◽  
Wafer Surface ◽  
Cross Sectional ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
The Difference

Two types of carrot defects with and without a shallow pit were found by mirror projection electron microscopy (MPJ) inspection in 4H-SiC epi wafer. Surface morphology and cross-sectional structure of prismatic stacking faults (PSFs) were investigated using MPJ and atomic force microscopy (AFM), transmission electron microscopy (TEM) and high-resolution scanning transmission electron microscopy (STEM). The depths of the surface grooves due to the PSFs, the stacking sequences around the PSFs and the structure of the Frank-type stacking faults which were connected to the PSFs were different. We discuss the difference between the two types of carrot defects.

Effect of Heavy Mass Ion (Gold) and Light Mass Ion (Boron) Irradiation on Microstructure of Tungsten

2019 ◽  
Vol 25 (6) ◽  
pp. 1442-1448
Author(s):  
Prashant Sharma ◽  
Padivattathumana Maya ◽  
Satyaprasad Akkireddy ◽  
Prakash M. Raole ◽  
Anil K. Tyagi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Defect Structures ◽  
Transmission Electron ◽  
Tungsten Foil ◽  
The Difference ◽  
Boron Ions ◽  
Small Clusters ◽  
Gold Ion

AbstractThe difference in the defect structures produced by different ion masses in a tungsten lattice is investigated using 80 MeV Au7+ ions and 10 MeV B3+ ions. The details of the defects produced by ions in recrystallized tungsten foil samples are studied using transmission electron microscopy. Dislocations of type b = 1/2[111] and [001] were observed in the analysis. While highly energetic gold ion produced small clusters of defects with very few dislocation lines, boron has produced large and sparse clusters with numerous dislocation lines. The difference in the defect structures could be due to the difference in separation between primary knock-on atoms produced by gold and boron ions.

Heat-treatment retention time dependence of polyvinylidenechloride-based carbons on their application to electric double-layer capacitors

2003 ◽  
Vol 18 (3) ◽  
pp. 693-701 ◽  
Author(s):  
M. Endo ◽  
Y. J. Kim ◽  
K. Ishii ◽  
T. Inoue ◽  
T. Nomura ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Transmission Electron Microscopy ◽  
Double Layer ◽  
Retention Time ◽  
Electric Double Layer ◽  
Electrode System ◽  
Treatment Retention ◽  
Transmission Electron ◽  
The Difference

The heat-treatment retention time effect of carbonized polyvinylidenechloride (PVDC) was investigated. Homogeneous PVDC with a crystallite size of 267 Å was used as a precursor material for an electric double-layer capacitor electrode. The P-120m material, which was heat treated for 120 min at 700 °C, shows a larger specific capacitance than any other material in this study. It shows the largest values reported up to now, reaching values as high as 100.2 F/g for a two-electrode system, which is equivalent to 400.8 F/g in a conventional three-compartment electrode system. It is difficult to distinguish the difference in the pore-size distribution by way of gas adsorption as the retention time is varied. However, the difference can be clarified using a novel method based on the analysis of transmission electron microscopy images. As the retention time for heat treatment increases, the pore size grows through the coalescence of small pores. Furthermore, a new concept for the electric double-layer capacitance is suggested on the basis of analysis of the transmission electron microscopy observations.

Nano-Crystalline Structure in Mg2Si/Mg-2.5Er-5Zn Composite on the Route of Repeated Plastic Working Process

2010 ◽  
Vol 667-669 ◽  
pp. 635-639
Author(s):  
Wen Bo Du ◽  
Xu Dong Wang ◽  
Zhao Hui Wang ◽  
Shu Bo Li
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Second Phase ◽  
Plastic Working ◽  
Nano Crystalline ◽  
Transmission Electron ◽  
The Matrix ◽  
Nonequilibrium Grain Boundaries ◽  
The Difference

The Mg-5Zn-2.5Er matrix composite reinforced with the in-situ synthesized Mg2Si second phase particles was fabricated via repeated plastic working (RPW) process. The microstructures and the nanocrystals in the composite have been investigated using transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HREM) and energy dispersive X-ray (EDX). Great deals of nanocrystals were found in the matrix, and they were around the in-situ synthesized Mg2Si. The HREM analysis showed that the size of nanocrystals was in the range of 5-10 nm, and the difference in their crystallographic orientation was bigger than 15°. It is suggested that the formation of nanocrystals in the matrix is attributed to the RPW deformation process and to the intensive stresse fields around the in-situ synthesized Mg2Si particles, which suppress the growth of nanocrystals by forming nonequilibrium grain boundaries containing disordered dislocation networks and junction disclinations.

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