In Situ Observation of Melting and Solidification

1999 ◽  
Vol 589 ◽  
Author(s):  
H. Saka ◽  
S. Arai ◽  
S. Muto ◽  
H. Miyai ◽  
S. Tsukimoto
Keyword(s):  
Electron Microscope ◽  
Grain Boundaries ◽  
Eutectic Alloy ◽  
Atomic Structure ◽  
In Situ Observation ◽  
Metallic Materials ◽  
Experimental Image ◽  
In Situ Heating ◽  
Melting And Solidification

AbstractMelting and solidification of metallic materials have been observed directly using an in-situ heating experiment in an electron microscope. In pure Al melting initiates at the surface, while in a eutectic alloy melting initiates preferentially at eutectic interfaces and grain boundaries. The atomic structure of a solidliquid interface was identified by comparing an experimental image with computed ones.

In situ TEM observations of melting in nanosized eutectic Pb-Cd inclusions embedded in Al

1996 ◽  
Vol 54 ◽  
pp. 986-987
Author(s):  
S. Hagège ◽  
U. Dahmen ◽  
E. Johnson ◽  
A. Johansen ◽  
V.S. Tuboltsev
Keyword(s):  
Electron Microscope ◽  
Melt Spinning ◽  
Ternary Alloys ◽  
Solid Matrix ◽  
Eutectic System ◽  
In Situ Tem ◽  
In Situ Observation ◽  
Orientation Relationships ◽  
Transmission Electron

Small particles of a low-melting phase embedded in a solid matrix with a higher melting point offer the possibility of studying the mechanisms of melting and solidification directly by in-situ observation in a transmission electron microscope. Previous studies of Pb, Cd and other low-melting inclusions embedded in an Al matrix have shown well-defined orientation relationships, strongly faceted shapes, and an unusual size-dependent superheating before melting.[e.g. 1,2].In the present study we have examined the shapes and thermal behavior of eutectic Pb-Cd inclusions in Al. Pb and Cd form a simple eutectic system with each other, but both elements are insoluble in solid Al. Ternary alloys of Al (Pb,Cd) were prepared from high purity elements by melt spinning or by sequential ion implantation of the two alloying additions to achieve a total alloying addition of up to lat%. TEM observations were made using a heating stage in a 200kV electron microscope equipped with a video system for recording dynamic behavior.

In situ observation of interaction between grain boundaries during directional solidification of Si

2018 ◽  
Vol 148 ◽  
pp. 37-41 ◽  
Author(s):  
Lu-Chung Chuang ◽  
Kensaku Maeda ◽  
Haruhiko Morito ◽  
Keiji Shiga ◽  
Wolfram Miller ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Directional Solidification ◽  
In Situ Observation

In situ observation of the motion of ferroelectric domain walls in Bi4Ti3O12 single crystals

2016 ◽  
Vol 49 (5) ◽  
pp. 1645-1652 ◽  
Author(s):  
Wanneng Ye ◽  
Lingli Tang ◽  
Chaojing Lu ◽  
Huabing Li ◽  
Yichun Zhou
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Single Crystals ◽  
Transmission Electron Microscope ◽  
Domain Walls ◽  
Domain Switching ◽  
Ferroelectric Domain ◽  
In Situ Observation ◽  
Transmission Electron

Five types of ferroelectric domain walls (DWs) are present in Bi4Ti3O12 single crystals (Ye et al., 2015). Here their motion was investigated in situ using transmission electron microscopy and optical microscopy. The motion of P (a)-90° DWs, P (a)-180° DWs and P (c)-180° DWs was observed through electron beam poling in a transmission electron microscope. The growth of new P s(a)-180° nanodomains was frequently seen and they tended to nucleate at preexisting P s(a)-90° DWs. Irregularly curved P (c)-180° DWs exhibit the highest mobility, while migration over a short range occurs occasionally for faceted P s(a)-90° DWs. In addition, the motion of P s(a)-90° DWs and the growth/annihilation of new needle-like P s(a)-90° domains in a 20 µm-thick crystal were observed under an external electric field on an optical microscope. Most of the new needle-like P s(a)-90° domains nucleate at preexisting P s(a)-90° DWs and the former are much smaller than the latter. This is very similar to the situation for P s(a)-180° domain switching induced by electron beam poling in a transmission electron microscope. Our observations suggest the energy hierarchy for different domains of P s(c)-180° ≤ P s(a)-180° ≤ P s(a)-90° ≤ new needle-like P s(a)-90° in ferroelectric Bi4Ti3O12.

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