Line width Dependence of Stress Relaxation and Yield Behavior of Passivated Al(Cu) Lines

1994 ◽  
Vol 338 ◽  
Author(s):  
I.-S. Yeo ◽  
S.G.H. Anderson ◽  
C.-N. Liao ◽  
D. Jawarani ◽  
H. Kawasaki ◽  
...  

ABSTRACTStress relaxation behavior of thermally induced stresses in passivated line structures is strongly influenced by the metal yield strength. For some line geometries, stress relaxation can lead to void formation. In this study, bending beam measurements have been carried out to measure the thermal stress and stress relaxation behavior of passivated Al(l wt.% Cu) line structures with 3, 1, and 0.5 µm line widths. Our results reveal that stress relaxation in Al(Cu) films and lines shows log(time) kinetics consistent with a thermally activated dislocation glide mechanism. The kinetics of stress relaxation depend on line geometry and temperature, which can be explained by a combined effect of temperature (mass transport) and shear stress (driving force).

2018 ◽  
Vol 25 (5) ◽  
pp. 1015-1019 ◽  
Author(s):  
Muhammad Mansoor ◽  
Muhammad Shahid

AbstractThe mechanical properties and stress relaxation behavior of annealed aluminum-carbon nanotube composite were studied and compared with those of pure aluminum. The composite was prepared using an induction furnace, where 1.6 vol.% of multiwall carbon nanotubes were added in aluminum as strengthening material. It was found that the mechanical strength of the annealed composite was almost twice that of aluminum. The stress relaxation behavior of both materials was logarithmic in nature. However, the stress relaxation, hardening component, and intrinsic height of the thermally activated barrier were significantly influenced by the presence of nanotubes in the aluminum matrix. It was found that the stress relaxation rate of the composite was reduced (>30%) and the hardening component was increased (>100%) compared with that of aluminum. The calculated strengths of the thermally activated barriers for aluminum and the composite were 1.7 and 2.6 eV, respectively.


2014 ◽  
Vol 492 ◽  
pp. 86-89 ◽  
Author(s):  
Yan Yan Luo ◽  
Li Xin Wang ◽  
Ke Li ◽  
Ming Ming Lei ◽  
Guo Jin Liu ◽  
...  

This paper mainly studies the effect of temperature cycling on stress relaxation behavior of contacts for electrical connectors. Based on the analysis of the test specifications of electrical connectors, this paper provides a kind of test method on stress relaxation behavior of electrical connector contacts under temperature cycling conditions. The detecting circuit is designed; the test is carried out and finally, according to the test data, it can be concluded that 1) for the same temperature change, the absolute change of strain within the temperatures above zero is bigger than that within the subzero temperatures; 2) the deformation of contacts gradually increases as the number of cycles increases. The length of the degradation process for electrical connectors might be related with the high temperature value, temperature variation or temperature variation rate.


2016 ◽  
Vol 49 (5) ◽  
pp. 381-396 ◽  
Author(s):  
Farzad A Nobari Azar ◽  
Murat Şen

Natural rubber/chloroprene rubber (NR/CR) blends are among the commonly used rubber blends in industry and continuously are exposed to severe weather changes. To investigate the effects of accelerator type on the network structure and stress relaxation of unaged and aged NR/CE vulcanizates, tetramethyl thiuram disulfide, 2-mercaptobenzothiazole, and diphenyl guanidine accelerators have been chosen to represent fast, moderate, and slow accelerator groups, respectively. Three batches have been prepared with exactly the same components and mixing conditions differing only in accelerator type. Temperatures scanning stress relaxation and pulse nuclear magnetic resonance techniques have been used to reveal the structural changes of differently accelerated rubber blends before and after weathering. Nonoxidative thermal decomposition analyses have been carried out using a thermogravimetric analyzer. Results indicate that there is a strong interdependence between accelerator type and stress relaxation behavior, network structure, cross-linking density, and aging behavior of the blends. Accelerator type also affects decomposition energy of the blends.


2010 ◽  
Vol 107 (6) ◽  
pp. 063509 ◽  
Author(s):  
Xuanhe Zhao ◽  
Nathaniel Huebsch ◽  
David J. Mooney ◽  
Zhigang Suo

Sign in / Sign up

Export Citation Format

Share Document