scholarly journals In Situ Microstructure Observation of Steel Grades in the Semi-Solid State for Thixoforging Process by Using Confoncal Laser Scanning Microscopy

2014 ◽  
Vol 217-218 ◽  
pp. 15-22 ◽  
Author(s):  
Guo Chao Gu ◽  
Raphaël Pesci ◽  
Eric Becker ◽  
Laurent Langlois ◽  
Régis Bigot
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Microstructure Evolution ◽  
Laser Scanning ◽  
Diffusion Rate ◽  
Laser Scanning Microscopy ◽  
Alloying Elements ◽  
Steel Grades ◽  
Semi Solid

It is necessary to well understand the microstructure evolution during high speed heating and forming for steel thixoforging, since it determines the thixotropic flow behavior of materials in the semi-solid state. A new in situ technique - high temperature Confocal Laser Scanning Microscopy (CLSM) - was developed and used for studying the microstructure evolution directly at high temperature where the microstructure in the semi-solid state could not be preserved by quenching experiments for conventional 2D characterization. Several steel grades (C38LTT, 100Cr6 and M2) were investigated during heating from the as-received state to the semi-solid state and finally cooled to the solid state).It has been found that there is a significant difference in diffusion rate of alloying elements between these grades during heating and cooling. In M2, thanks to the high content of alloying elements and their low diffusion rate, the semi-solid temperature range is greater and its microstructure in the semi-solid state could be preserved by quenching or even at a low cooling rate, which means the microstructure of M2 in the semi-solid state can be characterized in room temperature on quenched M2 samples. On the contrary, the microstructure of other steel grades 100Cr6 and C38LTT in semi-solid state can only be revealed by CLSM at high temperature because of the lower volume fraction of alloying elements and their high diffusion rate. It is very interesting to use high temperature CLSM to in situ investigate the microstructure evolution in the semi-solid state, especially at low liquid fraction.

Development of Unconventional Processing of Steels in Semi-Solid State

2016 ◽  
Vol 256 ◽  
pp. 251-256
Author(s):  
Bohuslav Mašek ◽  
David Aišman ◽  
Filip Vančura ◽  
Martin F.X. Wagner ◽  
Hana Jirková ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
High Temperature ◽  
Solid State ◽  
Severe Plastic Deformation ◽  
Rapid Solidification ◽  
Process Conditions ◽  
In Situ Observation ◽  
Semi Solid

This paper describes selected capabilities of unconventional processing of steels in semi-solid state under various process conditions and with the use of various steel chemistries for obtaining unusual structures formed by rapid solidification in combination with other procedures. This investigation involves the use of severe plastic deformation techniques (SPD) and in-situ observation of the transformation of microstructure from solid state to semi-solid state at temperatures above 1200°C using a high-temperature microscope.

scholarly journals Determination of Quantity and Localization of Liquid in the Semi-Solid State Using both 3D X-Ray Microtomography and 2D Techniques for Steel Thixoforming

2012 ◽  
Vol 192-193 ◽  
pp. 191-196
Author(s):  
Guo Chao Gu ◽  
Raphaël Pesci ◽  
Eric Becker ◽  
Laurent Langlois ◽  
Régis Bigot
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Solid State ◽  
Room Temperature ◽  
Great Influence ◽  
Ex Situ ◽  
X Ray ◽  
Semi Solid

The distribution of liquid at the semi solid state is one of the most important parameters for steel thixoforging. It has a great influence on the viscosity of the material, on the flows and finally on the final shape and mechanical properties of the thixoforged parts. Both ex situ and in situ 3D X-ray microtomography characterizations have been carried out to determine the quantity and localization of liquid at high temperature of M2 steel slugs. Microtomography was first performed ex situ at room temperature on samples heated and quenched from semi-solid state. The specimens were also scanned in situ directly at high temperature. The obtained results have been compared to 2D observations using EDS technique in SEM on heated and quenched specimens. They showed a good correlation making both approaches very efficient for the study of the liquid zones at the semi-solid state

Real time and in situ observation of graphene growth on liquid metal surfaces via a carbon segregation method using high-temperature confocal laser scanning microscopy

RSC Advances ◽  
2016 ◽  
Vol 6 (103) ◽  
pp. 101235-101241 ◽  
Author(s):  
Pengcheng Yan ◽  
Yeon Joo Jeong ◽  
Mohammad F. Islam ◽  
P. Chris Pistorius
Keyword(s):  
High Temperature ◽  
Liquid Metal ◽  
Confocal Laser Scanning Microscopy ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
In Situ Observation ◽  
Laser Scanning Confocal Microscope

Determination of graphene formation and growth using direct,in situimaging with high-temperature laser scanning confocal microscope.

High-temperature in situ observation of Nd–Sm–Ba–Cu–O system by laser-scanning microscopy

2001 ◽  
Vol 357-360 ◽  
pp. 702-705
Author(s):  
S. Banzai ◽  
N. Sakai ◽  
N. Takazawa ◽  
S. Yoshizawa ◽  
G. Osabe ◽  
...  
Keyword(s):  
High Temperature ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Scanning Microscopy ◽  
In Situ Observation

3-D imaging of cells using a confocal laser scanning microscope and digital image processing

1988 ◽  
Vol 46 ◽  
pp. 96-97
Author(s):  
Thomas M. Jovin ◽  
Michel Robert-Nicoud ◽  
Donna J. Arndt-Jovin ◽  
Thorsten Schormann
Keyword(s):  
Laser Scanning ◽  
Confocal Laser Scanning Microscope ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Scanning Microscope ◽  
Laser Scanning Microscope ◽  
Biochemical Processes ◽  
Adjacent Structures

Light microscopic techniques for visualizing biomolecules and biochemical processes in situ have become indispensable in studies concerning the structural organization of supramolecular assemblies in cells and of processes during the cell cycle, transformation, differentiation, and development. Confocal laser scanning microscopy offers a number of advantages for the in situ localization and quantitation of fluorescence labeled targets and probes: (i) rejection of interfering signals emanating from out-of-focus and adjacent structures, allowing the “optical sectioning” of the specimen and 3-D reconstruction without time consuming deconvolution; (ii) increased spatial resolution; (iii) electronic control of contrast and magnification; (iv) simultanous imaging of the specimen by optical phenomena based on incident, scattered, emitted, and transmitted light; and (v) simultanous use of different fluorescent probes and types of detectors.We currently use a confocal laser scanning microscope CLSM (Zeiss, Oberkochen) equipped with 3-laser excitation (u.v - visible) and confocal optics in the fluorescence mode, as well as a computer-controlled X-Y-Z scanning stage with 0.1 μ resolution.

scholarly journals Influence of Aging on Corrosion Behaviour of the 6061 Cast Aluminium Alloy

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1821
Author(s):  
Ting He ◽  
Wei Shi ◽  
Song Xiang ◽  
Chaowen Huang ◽  
Ronald G. Ballinger
Keyword(s):  
Aluminium Alloy ◽  
Laser Scanning ◽  
Corrosion Behaviour ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Kelvin Probe ◽  
Force Microscopy ◽  
The Matrix ◽  
6061 Aluminium Alloy

The influence of AlFeSi and Mg2Si phases on corrosion behaviour of the cast 6061 aluminium alloy was investigated. Scanning Kelvin probe force microscopy (SKPFM), electron probe microanalysis (EPMA), and in situ observations by confocal laser scanning microscopy (CLSM) were used. It was found that Mg2Si phases were anodic relative to the matrix and dissolved preferentially without significantly affecting corrosion propagation. The AlFeSi phases’ influence on 6061 aluminium alloy local corrosion was greater than that of the Mg2Si phases. The corroded region width reached five times that of the AlFeSi phase, and the accelerating effect was terminated as the AlFeSi dissolved.

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