scholarly journals A framework for studying dynamics and stability of diffusive–reactive interfaces with application to Cu 6 Sn 5 intermetallic compound growth

2016 ◽  
Vol 472 (2190) ◽  
pp. 20160134 ◽  
Author(s):  
Anirudh Udupa ◽  
Subramanya Sadasiva ◽  
Ganesh Subbarayan
Keyword(s):  
Intermetallic Compound ◽  
Surface Diffusion ◽  
Reaction Rate ◽  
Surface Reaction ◽  
Phase Interface ◽  
Bulk Diffusion ◽  
Diffuse Interface ◽  
Surface Diffusivity ◽  
Intermetallic Compound Growth ◽  
The One

Often during phase growth, the rate of accretion, on the one hand, is determined by a competition between bulk diffusion and surface reaction rate. The morphology of the phase interface, on the other hand, is determined by an interplay between surface diffusivity and surface reaction rate. In this study, a framework to predict the growth and the morphology of an interface by modelling the interplay between bulk diffusion, surface reaction rate and surface diffusion is developed. The framework is demonstrated using the example of Cu–Sn intermetallic compound growth that is of significance to modern microelectronic assemblies. In particular, the dynamics and stability of the interface created when Cu and Sn react to form the compound Cu 6 Sn 5 is explored. Prior experimental observations of the Cu 6 Sn 5 –Sn interface have shown it to possess either a scalloped, flat or needle-shaped morphology. Diffuse interface simulations are carried out to elucidate the mechanism behind the interface formation. The computational model accounts for the bulk diffusion of Cu through the intermetallic compound, reaction at the interface to form Cu 6 Sn 5 , surface diffusion of Cu 6 Sn 5 along the interface and the influence of the electric current density in accelerating the bulk diffusion of Cu. A stability analysis is performed to identify the conditions under which the interface evolves into a flat, scalloped or needle-shaped structure.

Direct observation of Fe-Al-Zn ternary intermetallic compound and its transformation during the early stage of hot-dip galvanizing

1993 ◽  
Vol 51 ◽  
pp. 1116-1117
Author(s):  
C. S. Lin ◽  
W. A. Chiou ◽  
M. Meshii
Keyword(s):  
Intermetallic Compound ◽  
Reaction Rate ◽  
Diffusion Rate ◽  
Early Stage ◽  
Zinc Bath ◽  
Steel Sheets ◽  
Direct Observations ◽  
Solid Iron ◽  
Iron And Zinc ◽  
Ternary Intermetallic Compound

The galvannealed steel sheets have received ever increased attention because of their excellent post-painting corrosion resistance and good weldability. However, its powdering and flaking tendency during press forming processes strongly impairs its performance. In order to optimize the properties of galvanneal coatings, it is critical to control the reaction rate between solid iron and molten zinc.In commercial galvannealing line, aluminum is added to zinc bath to retard the diffusion rate between iron and zinc by the formation of a thin layer of Al intermetallic compound on the surface of steel at initial hot-dip galvanizing. However, the form of this compound and its transformation are still speculated. In this paper, we report the direct observations of this compound and its transformation.The specimens were prepared in a hot-dip simulator in which the steel was galvanized in the zinc bath containing 0.14 wt% of Al at a temperature of 480 °C for 5 seconds and was quenched by liquid nitrogen.

scholarly journals Comparing hydrogen absorption kinetics of the samples of intermetallic compound and metal hydride compact on its basis

2021 ◽  
Vol 2057 (1) ◽  
pp. 012043
Author(s):  
I A Romanov ◽  
V I Borzenko ◽  
A N Kazakov
Keyword(s):  
Intermetallic Compound ◽  
Metal Hydride ◽  
Hydrogen Absorption ◽  
Reaction Rate ◽  
Nickel Foam ◽  
High Confidence ◽  
Compact Sample ◽  
Kinetics Of ◽  
Rate Controlling Step ◽  
Absorption Of Hydrogen

Abstract This work is devoted to an experimental study and comparison of the kinetics of hydrogen absorption by an intermetallic compound LaNi4.4Al0.3Fe0.3 in form of pure intermetallic compound free backfill and a compact based on it obtained by cold pressing with a spiral matrix of nickel-foam. To calculate the kinetic parameters of the hydrogen absorption reaction, the initial rates method is used. The PCT absorption isotherms are measured at temperatures of 313, 333, and 353 K. The experimental data are described with quite high confidence by the chosen model, which assumes that the reaction rate controlling step is the dissociative absorption of hydrogen on the surface of the a-phase. The rate of hydrogen absorption increases with increasing pressure drop and temperature. It is shown that the rate of hydrogen absorption by the sample of pure IMC is significantly less dependent on temperature compared to the compact sample. In addition, the reaction rate at temperatures of 313 and 333 K is higher for the free backfill sample, and at 353 K it is higher for the metal hydride compact. The values of the absorption constant and the activation energy of the hydrogen absorption reaction are determined for both samples.

Reaction rate of combustion synthesis of an intermetallic compound

1998 ◽  
Vol 95 (2) ◽  
pp. 175-181 ◽  
Author(s):  
Tomohiro Akiyama ◽  
Hiromichi Isogai ◽  
Jun-ichiro Yagi
Keyword(s):  
Intermetallic Compound ◽  
Combustion Synthesis ◽  
Reaction Rate ◽  
Rate Of Combustion

scholarly journals Tailoring atomic diffusion for in situ fabrication of different heterostructures

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hui Zhang ◽  
Tao Xu ◽  
Kaihao Yu ◽  
Wen Wang ◽  
Longbing He ◽  
...  
Keyword(s):  
Surface Diffusion ◽  
Bulk Diffusion ◽  
Diffusion Reaction ◽  
Atomic Diffusion ◽  
Solid Diffusion ◽  
In Situ Fabrication ◽  
State Diffusion ◽  
New Process ◽  
Insight Into

AbstractAtomic diffusion has been recognized as a particularly powerful tool in the synthesis of heterostructures. However, controlled atomic diffusion is very difficult to achieve in the fabrication of individual nanostructures. Here, an electrically driven in situ solid-solid diffusion reaction inside a TEM is reported for the controlled fabrication of two different hetero-nanostructures in the Ag-Te system. Remarkably, the morphology and structure of the as-formed heterostructures are strongly dependent on the path of atomic diffusion. Our experiments revealed that the surface diffusion of Te atoms to Ag nanowires leads to a core-shell structure, while the bulk diffusion of Ag atoms give rise to a Ag2Te-Te segmented heterostructure. Heat released by Joule heating caused the surface diffusion process to be replaced by bulk diffusion and thereby determined the structure of the final product. Our experimental results provide an insight into solid-state diffusion reactions under an electric field and also propose a new process for the fabrication of complex nanostructures.

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