Electroplastic effect associated with the dislocation generation in the initially dislocation-free silicon whiskers

ABSTRACTAn approach is developed for understanding the cross-hatch morphology in lattice mismatched heteroepitaxial film growth. It is demonstrated that both strain relaxation associated with misfit dislocation formation and subsequent step elimination (e.g. by step-flow growth) are responsible for the appearance of nanoscopic surface height undulations (0.1-10 nm) on a mesoscopic (∼100 nm) lateral scale. The results of Monte Carlo simulations for dislocation- assisted strain relaxation and subsequent film growth predict the development of cross-hatch patterns with a characteristic surface undulation magnitude ∼50 Å in an approximately 70% strain relaxed In0.25Ga0.75As layers. The model is supported by atomic force microscopy (AFM) observations of cross-hatch morphology in the same composition samples grown well beyond the critical thickness for misfit dislocation generation.

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Mechanical and etching properties of dual ion beam deposited hydrogen-free silicon nitride films

Journal of Vacuum Science & Technology A Vacuum Surfaces and Films ◽

10.1116/1.1392397 ◽

2001 ◽

Vol 19 (5) ◽

pp. 2542-2548 ◽

Cited By ~ 5

Author(s):

M. P. Tsang ◽

C. W. Ong ◽

N. Chong ◽

C. L. Choy ◽

P. K. Lim ◽

...

Keyword(s):

Silicon Nitride ◽

Ion Beam ◽

Silicon Nitride Films ◽

Free Silicon

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Enhancement of the tensile shear strength for joining low-ductility aluminium to high-strength steel by using electrically-assisted mechanical clinching (EAMC)

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1177/0954405421995652 ◽

2021 ◽

pp. 095440542199565

Author(s):

Abozar Barimani-Varandi ◽

Abdolhossein Jalali Aghchai

Keyword(s):

Shear Strength ◽

High Strength Steel ◽

High Strength ◽

Fe Model ◽

Tensile Shear Strength ◽

Tensile Shear ◽

Electroplastic Effect ◽

Fracture Displacement ◽

Electrically Assisted ◽

Mechanical Clinching

The present work studied the enhancement of the tensile shear strength for joining AA6061-T6 aluminium to galvanized DP590 steel via electrically-assisted mechanical clinching (EAMC) using an integrated 2D FE model. To defeat the difficulties of joining low-ductility aluminium alloy to high-strength steel, the electroplastic effect obtained from the electrically-assisted process was applied to enhance the clinch-ability. For this purpose, the results of experiments performed by the chamfering punches with and without electrically-assisted pre-heating were compared. Joint cross-section, failure load, failure mode, fracture displacement, material flow, and failure mechanism were assessed in order to study the failure behaviour. The results showed that the joints clinched at the EAMC condition failed with the dominant dimpled mechanism observed on the fracture surface of AA6061 side, achieved from the athermal effect of the electroplasticity. Besides, these joints were strengthened 32% with a much more fracture displacement around 20% compared with non-electrically-assisted pre-heating.

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Dislocation-Free Silicon on Sapphire by Wafer Bonding

Japanese Journal of Applied Physics ◽

10.1143/jjap.33.514 ◽

1994 ◽

Vol 33 (Part 1, No. 1B) ◽

pp. 514-518 ◽

Cited By ~ 7

Author(s):

Takao Abe ◽

Konomu Ohki ◽

Atsuo Uchiyama ◽

Kazushi Nakazawa ◽

Yasuyuki Nakazato

Keyword(s):

Wafer Bonding ◽

Free Silicon

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Dislocation Generation and Crack Propagation in Metals Examined in Molecular Dynamics Simulations

MRS Proceedings ◽

10.1557/proc-278-173 ◽

1992 ◽

Vol 278 ◽

Cited By ~ 6

Author(s):

J. A. Rifkin ◽

C. S. Becquart ◽

D. Kim ◽

P. C. Clapp

Keyword(s):

Crack Propagation ◽

Atomistic Simulations ◽

Many Body ◽

Dislocation Generation ◽

Embedded Atom ◽

Stress Levels ◽

Different Temperatures ◽

The Many ◽

Dynamics Simulations ◽

Many Body Interactions

AbstractWe have carried out a series of atomistic simulations on arrays of about 10,000 atoms containing an atomically sharp crack and subjected to increasing stress levels. The ordered stoichiometric alloys B2 NiAl, B2 RuAl and A15 Nb3AI have been studied at different temperatures and stress levels, as well as the elements Al, Ni, Nb and Ru. The many body interactions used in the simulations were derived semi-empirically, using techniques related to the Embedded Atom Method. Trends in dislocation generation rates and crack propagation modes will be discussed and compared to experimental indications where possible, and some of the simulations will be demonstrated in the form of computer movies.

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