Coarsening Kinetics of Semi-solid A356–5wt%TiB2 in situ Composite

2015 ◽  
Vol 68 (6) ◽  
pp. 1075-1080 ◽  
Author(s):  
S. Deepak Kumar ◽  
Mihira Acharya ◽  
A. Mandal ◽  
M. Chakraborty
2017 ◽  
Vol 127 ◽  
pp. 230-243 ◽  
Author(s):  
X. Li ◽  
F. Bottler ◽  
R. Spatschek ◽  
A. Schmitt ◽  
M. Heilmaier ◽  
...  

2006 ◽  
Vol 116-117 ◽  
pp. 205-208 ◽  
Author(s):  
P. Babaghorbani ◽  
S. Salarfar ◽  
Mahmoud Nili-Ahmadabadi

Reheating process in the semi-solid state is a very important step in the thixoforming process. In this research semi-solid ductile cast iron and Al alloys (Al-2.5Si, Al356) prepared by inclined plate method, were reheated to examine the effect of reheating conditions on the microstructure and coarsening kinetics of the alloys. For ductile cast iron, solid fraction at different reheating temperatures and holding times was obtained and based on these results the optimum reheating temperature range was determined. In the case of Al alloys increase of holding time in the semi-solid state, leads to increase of liquid fraction, solid grain size and improvement of sphericity of solid particles. In addition, the results show that coarsening kinetics of microstructures of both alloys during reheating was diffusion controlled and can be mostly treated by Ostwald ripening theory.


2019 ◽  
Vol 154 ◽  
pp. 116-126 ◽  
Author(s):  
Lingling Fan ◽  
Mingyang Zhou ◽  
Yuwenxi Zhang ◽  
Qi Tang ◽  
Gaofeng Quan ◽  
...  

Author(s):  
J. Drucker ◽  
R. Sharma ◽  
J. Kouvetakis ◽  
K.H.J. Weiss

Patterning of metals is a key element in the fabrication of integrated microelectronics. For circuit repair and engineering changes constructive lithography, writing techniques, based on electron, ion or photon beam-induced decomposition of precursor molecule and its deposition on top of a structure have gained wide acceptance Recently, scanning probe techniques have been used for line drawing and wire growth of W on a silicon substrate for quantum effect devices. The kinetics of electron beam induced W deposition from WF6 gas has been studied by adsorbing the gas on SiO2 surface and measuring the growth in a TEM for various exposure times. Our environmental cell allows us to control not only electron exposure time but also the gas pressure flow and the temperature. We have studied the growth kinetics of Au Chemical vapor deposition (CVD), in situ, at different temperatures with/without the electron beam on highly clean Si surfaces in an environmental cell fitted inside a TEM column.


Author(s):  
R-R. Lee

Partially-stabilized ZrO2 (PSZ) ceramics have considerable potential for advanced structural applications because of their high strength and toughness. These properties derive from small tetragonal ZrO2 (t-ZrO2) precipitates in a cubic (c) ZrO2 matrix, which transform martensitically to monoclinic (m) symmetry under applied stresses. The kinetics of the martensitic transformation is believed to be nucleation controlled and the nucleation is always stress induced. In situ observation of the martensitic transformation using transmission electron microscopy provides considerable information about the nucleation and growth aspects of the transformation.


Author(s):  
M. Park ◽  
S.J. Krause ◽  
S.R. Wilson

Cu alloying in Al interconnection lines on semiconductor chips improves their resistance to electromigration and hillock growth. Excess Cu in Al can result in the formation of Cu-rich Al2Cu (θ) precipitates. These precipitates can significantly increase corrosion susceptibility due to the galvanic action between the θ-phase and the adjacent Cu-depleted matrix. The size and distribution of the θ-phase are also closely related to the film susceptibility to electromigration voiding. Thus, an important issue is the precipitation phenomena which occur during thermal device processing steps. In bulk alloys, it was found that the θ precipitates can grow via the grain boundary “collector plate mechanism” at rates far greater than allowed by volume diffusion. In a thin film, however, one might expect that the growth rate of a θ precipitate might be altered by interfacial diffusion. In this work, we report on the growth (lengthening) kinetics of the θ-phase in Al-Cu thin films as examined by in-situ isothermal aging in transmission electron microscopy (TEM).


2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell

We have directly observed the <i>in situ</i> self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. This work has elucidated one general kinetic pathway for the process of PEC micelle formation, which provides useful physical insights for increasing our fundamental understanding of complexation and self-assembly dynamics driven by electrostatic interactions that occur on ultrafast timescales.


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