S.E.M.-T.E.M. Image Comparison

1971 ◽  
Vol 29 ◽  
pp. 132-133
Author(s):  
G. M. Greene ◽  
J. W. Sprys
Keyword(s):  
Electron Microscope ◽  
Low Carbon Steel ◽  
Secondary Emission ◽  
Low Carbon ◽  
Preparation Time ◽  
Actual Surface ◽  
Fine Detail ◽  
Transmission Electron ◽  
Transmission Study ◽  
Large Sections

The present study demonstrates that fracture surfaces appear strikingly different when observed in the transmission electron microscope by replication and in the scanning electron microscope by backscattering and secondary emission. It is important to know what form these differences take because of the limitations of each instrument. Replication is useful for study of surfaces too large for insertion into the S.E.M. and for resolution of fine detail at high magnification with the T.E.M. Scanning microscopy reduces sample preparation time and allows large sections of the actual surface to be viewed.In the present investigation various modes of the S.E.M. along with the transmission mode in the T.E.M. were used to study one area of a fatigue surface of a low carbon steel. Following transmission study of a platinum carbon replica in the T.E.M. and S.E.M. the replica was coated with a gold layer approximately 200A° in thickness to improve electron emission.

Microstructure of the Acid Welding Slag

2012 ◽  
Vol 249-250 ◽  
pp. 914-917
Author(s):  
Yuan Bin Zhang ◽  
Kai Zhang
Keyword(s):  
Electron Microscope ◽  
Amorphous Matrix ◽  
Low Carbon Steel ◽  
Optical Microscope ◽  
Crystal Phase ◽  
Low Carbon ◽  
Extrusion Press ◽  
Transmission Electron ◽  
Welding Slag ◽  
Welding Electrode

Several E4303 type welding electrodes with different coating compositions were designed and manufactured using TL-25 welding electrode extrusion press. Welding slags of these electrodes were collected after welding on the low carbon steel, then the microstructure and the phase constitutes of the slags were investigated by optical microscope,scan electron microscope (SEM), electron probe microanalyzer (EPMA), Transmission electron microscope (TEM) and X-ray diffraction (XRD). It was indicated that the slags were mainly composed of amorphous matrix and Fe2MnTi3O10 crystal phase. Fe, Mn and Ti were the main elements to form the crystal phase, while Si, Al and Ca were mostly distributed in the amorphous matrix. The formation of the crystal phase in the slag could be controlled by adjusting the amount and the proportion of Fe, Mn and Ti in the welding rod coating.

scholarly journals Detection and Determination of Solute Carbon in Grain Interior to Correlate with the Overall Carbon Content and Grain Size in Ultra-Low-Carbon Steel

2013 ◽  
Vol 19 (S5) ◽  
pp. 66-68 ◽  
Author(s):  
Jiling Dong ◽  
Yinsheng He ◽  
Chan-Gyu Lee ◽  
Byungho Lee ◽  
Jeongbong Yoon ◽  
...  
Keyword(s):  
Grain Size ◽  
Electron Microscope ◽  
Carbon Content ◽  
Three Dimensional ◽  
Low Carbon Steel ◽  
Atom Probe ◽  
Optical Microscope ◽  
Low Carbon ◽  
Transmission Electron ◽  
Solute Carbon

AbstractIn this study, every effort was exerted to determine and accumulate data to correlate microstructural and compositional elements in ultra-low-carbon (ULC) steels to variation of carbon content (12–44 ppm), manganese (0.18–0.36%), and sulfur (0.0066–0.001%). Quantitative analysis of the ULC steel using optical microscope, scanning electron microscope, transmission electron microscope, and three-dimensional atom probe revealed the decrease of grain size and dislocation density with the increase of carbon contents and/or increase of the final delivery temperature. For a given carbon content, the grain interior carbon concentration increases as the grain size increases.

Mechanism of Forming Joining on Backward Extrusion Forged Bonding Process

2014 ◽  
Vol 966-967 ◽  
pp. 461-470
Author(s):  
Yoshinori Yoshida ◽  
Takashi Ishikawa ◽  
Tomoaki Suganuma
Keyword(s):  
Electron Microscope ◽  
Tensile Test ◽  
Bonding Strength ◽  
Pure Aluminum ◽  
Low Carbon Steel ◽  
Scanning Transmission Electron Microscope ◽  
Low Carbon ◽  
Backward Extrusion ◽  
Transmission Electron ◽  
Scanning Transmission

A backward extrusion forged bonding using low carbon steel and pure aluminum is conducted. The bonding strength between the materials is evaluated by a micro tensile test that is cut out at the bonding boundary. The maximum bonding strength is larger than that of the aluminum. In addition, the metallurgical mechanism of the joining of the backward extrusion forged bonding is investigated by means of a scanning transmission electron microscope (STEM). An intermetallic compound (IMC) layer is produced at the boundary with a thickness of about 3 nm. The process is applied for bonding between aluminum-nickel and between aluminum-copper. The bonding strength between the materials was evaluated by using a micro tensile test and the maximum bonding strength is shown. Fractured surfaces of the tensile specimens are observed by scanning electron microscope (SEM) and relationship between bonding strength and position on the boundary is discussed.

scholarly journals Magnetism and Microstructure Characterization of Phase Transitions in a Steel

2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
M. Güler
Keyword(s):  
Mössbauer Spectroscopy ◽  
Phase Transitions ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Mossbauer Spectroscopy ◽  
Low Carbon Steel ◽  
Magnetic Characteristics ◽  
Low Carbon ◽  
Mößbauer Spectroscopy ◽  
Scanning Electron

We present phase transitions in a low carbon steel according to existing phases and their magnetism. Scanning electron microscope employed research to clarify and evaluate the microstructural details. Additionally, we utilized from Mössbauer spectroscopy for magnetic characteristics of different existed phases. Scanning electron microscope examinations showed that the pure state of the steel was fully in the ferrite phase with equiaxed grains. Moreover, subsequent heat treatments on the studied steel also ensured the first austenite and then pearlite phase formation. Mössbauer spectroscopy of these phases appeared as a paramagnetic single-line absorption peak for the austenite phase and ferromagnetic six-line spectra for both ferrite and pearlite phases. From Mössbauer data, we determined that the internal magnetic fields of ferrite and pearlite phases were as 32.2 Tesla and 31.3 Tesla, respectively.

Early Scanning Electron Microscopy

1969 ◽  
Vol 27 ◽  
pp. 2-3
Author(s):  
W.C. Nixon
Keyword(s):  
Electron Microscope ◽  
Electron Emission ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Secondary Emission ◽  
Specimen Surface ◽  
Time Base ◽  
Transmission Electron ◽  
Cathode Ray Tube ◽  
Scanning Electron

The transmission electron microscope can be traced back to the work of K. Knoll and E. Ruska in Berlin who succeeded in 1931 in demonstrating a two lens electron microscope. The scanning electron microscope may also be traced back to the work of M. Knoll in 1935, during a study of secondary electron emission from surfaces. Two cathode ray tubes were used with a time-base generator supplying deflection signals to both tubes at once. The specimen under test was sealed into the first tube and the electron beam from the gun was scanned across the specimen surface and the variations in specimen current formed the signal. This signal was used to modulate the grid of the second cathode ray tube and the image displayed gave the variation in secondary emission on the specimen surface. In one case the word “Stuggart” was shown.

Scanning Electron Miscroscopy of Marsilea Sperm

1975 ◽  
Vol 33 ◽  
pp. 574-575
Author(s):  
C. Y. Shih
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Light Microscope ◽  
Fine Detail ◽  
Transmission Electron ◽  
Whole Mount ◽  
Surface Detail ◽  
Scanning Electron

Although spermatogenesis in Marsilea has been studied initially by Sharp with the light microscope (LM), and subsequently by Mizukami and Gall with the transmission electron microscope (TEM), the overall organization of the sperm has not been recorded in detail with photomicrograph. The small size of the sperm (about 16 micrometers in diameter) makes it difficult to resolve the fine detail with the IM and the specimens are too thick to derive useful information by studying whole mount preparations with the TEM. The SEM with a magnification and resolution range which is intermediate between the LM and TEM can be useful to characterize the organization and surface detail of the Marsilea sperm.Marsilea is a water fern which has the appearance of a four leaf clover. The sporangia are enclosed within a hard, rounded sporocarp which is located at the base of the leaf. Germination of the mature sporocarp can be hastened in the laboratory by excising a small piece of the wall and immersing the sporocarp in water.

Fatigue Damage Detection in 2024-T3 Aluminum, Titanium, and Low Carbon Steel by Optical Correlation

1977 ◽  
Vol 99 (4) ◽  
pp. 319-323 ◽  
Author(s):  
W. L. Haworth ◽  
V. K. Singh ◽  
R. K. Mueller
Keyword(s):  
Carbon Steel ◽  
Fatigue Damage ◽  
Large Fraction ◽  
Low Carbon Steel ◽  
Initial Surface ◽  
Low Carbon ◽  
Optical Correlation ◽  
Actual Surface ◽  
Notched Specimens ◽  
Third Stage

Optical correlation techniques were used to monitor fatigue damage in three metals of different strength and ductility, namely 2024-T3 aluminum alloy, commercial purity titanium, and low carbon steel. Topographical information from the specimen surface is stored holographically and compared with the actual surface as the fatigue test proceeds. Results are presented as curves of correlation intensity (CI) versus number of fatigue cycles, and data are compared for unnotched aluminum sheet specimens and notched specimens of all three materials. CI curves from both notched and unnotched 2024-T3 specimens show the same general three-stage form, and the onset of the third stage corresponds to the presence of a growing fatigue crack. The overall loss of CI over the effective life of the specimen, however, is lower for notched specimens, where fatigue damage is limited to a relatively small area of the illuminated surface. CI curves from titanium and steel specimens also develop in three stages, but for steel the initial region of the curve is protracted and the overall loss in CI is relatively large. This behavior occurs because the steel is relatively ductile and consequently the fatigue damage develops over a large fraction of the illuminated surface. Finally, the effect of the initial surface finish on the CI curve is discussed for all three materials.

Microstructures of Infiltrated Layer and Friction Properties of Low-Carbon Cr-Ni-Mo Bearing Steel during Duplex Surface Finishing Process

2014 ◽  
Vol 788 ◽  
pp. 317-322
Author(s):  
Chuan Xu ◽  
Mao Sheng Yang ◽  
Ai Qiong Ma ◽  
Shan Ju Zheng
Keyword(s):  
Electron Microscope ◽  
Point Contact ◽  
Bearing Steel ◽  
Surface Finishing ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
Gradient Distribution ◽  
Transmission Electron ◽  
Finishing Process ◽  
Carburizing Process

The carburizing behavior of low-carbon Cr-Ni-Mo, the nitriding behavior of C-Cr-W bearing steel and the carburizing process prior to nitriding of low-carbon Cr-Ni-Mo bearing steel were mainly investigated in this paper through the contrastive analysis of microstructures and properties by employing scanning electron microscope (SEM), transmission electron microscope (TEM) and X-Ray Diffraction XRD, etc. The result indicated that compared to the simple carburizing and nitriding process, the material that experienced the duplex surface finishing process could obtain a good infiltrated layer’s microstructure and excellent mechanical properties. The thickness of infiltrated layer was 1.8mm. The hardness of surface could reach 1100HV, and the infiltrated layer had a reasonable hardness gradient distribution. Meanwhile the test materials through duplex surface finishing process exhibited good friction properties in the aspect of point contact in dry friction.

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