Au-Sn bonding metallurgy of TAB contacts and its influence on the Kirkendall effect in the ternary Cu-Au-Sn system

Author(s):  
E. Zakel ◽  
H. Reichl
Keyword(s):  
2021 ◽  
Vol 493 ◽  
pp. 229688
Author(s):  
Minjun Kim ◽  
Hyunho Seok ◽  
N. Clament Sagaya Selvam ◽  
Jinil Cho ◽  
Gwan H. Choi ◽  
...  

Author(s):  
Nannan Chen ◽  
Hongliang Wang ◽  
Jingjing Li ◽  
Vic Liu ◽  
James Schroth

Abstract Dissimilar materials of copper (Cu) to aluminum (Al) with nickel-phosphorus (Ni-P) coatings were joined using resistance spot welding. The Ni-P coatings were electroless plated on the Al surfaces to eliminate the formation of brittle Cu-Al intermetallic compounds (IMCs) at the faying interface between Cu and Al. Three welding schedules with various heat input were employed to produce different interfacial microstructure. The evolution of interfaces in terms of phase constitution, elemental distribution and defects (gaps and voids) was characterized and the formation mechanisms were elucidated. During the welding process, the bonding between Cu and Ni-P forms through solid-state diffusion, while the faster diffusion rate of Cu relative to Ni and P atoms promotes the generation of sub-micron voids. As the heat input increases, gaps at the Cu/Ni-P interface diminish accompanied by increase of sub-micron voids. A moderate schedule helps to remove the gaps and inhibits the void formation. An Al3Ni layer and nanovoids were found around the interface of Ni-P/Al. The increased heat input decreases the grain size of Al3Ni at the interface by eutectic remelting and increases the nanovoids by enhanced nanoscale Kirkendall effect.


2018 ◽  
Vol 775 ◽  
pp. 441-447
Author(s):  
Dong Bok Lee ◽  
Min Jung Kim ◽  
Gyu Chul Cho ◽  
Soon Young Park ◽  
Poonam Yadav

The high-temperature corrosion behavior of Ni3Al+2.9 wt% Cr alloy was studied in SO2-containing environment. Corrosion tests were carried out at 900, 1000, and 1100 °C for 100 h in atmospheric Ar-0.2% SO2 gas. The alloy corroded relatively slowly due mainly to formation of Al2O3 in the scale. Its corrosion kinetics deviated from the parabolic corrosion rate law to a certain extent owing to ensuing scale spallation. This was attributed to (1) stress generated during scaling and the subsequent cooling period, (2) voids that formed due to the Kirkendall effect, and (3) incorporation of sulfur in the scale. The scale that formed after corrosion at 900 °C consisted of the outer NiO scale, middle NiAl2O4 scale, and inner Al2O3 scale. The increased corrosion rate at 1000 and 1100 °C led to formation of the outer NiO scale, and inner Al2O3 scale.


2008 ◽  
Vol 591-593 ◽  
pp. 673-678 ◽  
Author(s):  
Michelangelo Durazzo ◽  
Humberto Gracher Riella

The direct incorporation of Gd2O3 powder into UO2 powder by dry mechanical blending is the most attractive process for producing UO2-Gd2O3 nuclear fuel. However, previous experimental results by our group indicated that pore formation due to the Kirkendall effect delays densification and, consequently, diminishes the final density of this type of nuclear fuel. Considering this mechanism as responsible for the poor sintering behavior of UO2-Gd2O3 fuel prepared by the mechanical blending method, it was possible to propose, discuss and, in certain cases, preliminarily test feasible adjustments in fabrication procedures that would minimize, or even totally compensate, the negative effects of pore formation due to the Kirkendall effect. This work presents these considerations.


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