Measuring Residual Stress on the Nanometer Scale - Novel Tools for Fundamental and Applied Research

2012 ◽  
Vol 1424 ◽  
Author(s):  
R. B. Wehrspohn ◽  
M. Krause ◽  
C. Schriever

ABSTRACTIn the present paper, strain measurements based on second harmonic generation (SHG) and electron backscatter diffraction (EBSD) is demonstrated via two illustrative applications. While SHG gains access to strains in buried interfaces, EBSD can be used to measure strains in crystalline thin films with high spatial resolution on the order of tens of nanometers and high surface sensitivity. In addition, target preparation using low-voltage ion beam milling is demonstrated, gaining access to unstrained sample positions in strained silicon on insulator (sSOI) systems which are necessary for common “pattern-shift” methodologies.

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Orkun Furat ◽  
Lukas Petrich ◽  
Donal P. Finegan ◽  
David Diercks ◽  
Francois Usseglio-Viretta ◽  
...  

AbstractAccurately capturing the architecture of single lithium-ion electrode particles is necessary for understanding their performance limitations and degradation mechanisms through multi-physics modeling. Information is drawn from multimodal microscopy techniques to artificially generate LiNi0.5Mn0.3Co0.2O2 particles with full sub-particle grain detail. Statistical representations of particle architectures are derived from X-ray nano-computed tomography data supporting an ‘outer shell’ model, and sub-particle grain representations are derived from focused-ion beam electron backscatter diffraction data supporting a ‘grain’ model. A random field model used to characterize and generate the outer shells, and a random tessellation model used to characterize and generate grain architectures, are combined to form a multi-scale model for the generation of virtual electrode particles with full-grain detail. This work demonstrates the possibility of generating representative single electrode particle architectures for modeling and characterization that can guide synthesis approaches of particle architectures with enhanced performance.


2012 ◽  
Vol 715-716 ◽  
pp. 41-50 ◽  
Author(s):  
Michael Ferry ◽  
Wan Qiang Xu ◽  
M. Zakaria Quadir ◽  
Nasima Afrin Zinnia ◽  
Kevin J. Laws ◽  
...  

A focused ion beam (FIB) coupled with high resolution electron backscatter diffraction (EBSD) has emerged as a useful tool for generating crystallographic information in reasonably large volumes of microstructure. In principle, data generation is reasonably straightforward whereby the FIB is used as a high precision serial sectioning device for generating consecutive milled surfaces suitable for mapping by EBSD. The successive EBSD maps generated by serial sectioning are combined using various post-processing methods to generate crystallographic volumes of the microstructure. This paper provides an overview of the use of 3D-EBSD in the study of various phenomena associated with thermomechanical processing of both crystalline and semi-crystalline alloys and includes investigations on the crystallographic nature of microbands, void formation at particles, phase redistribution during plastic forming, and nucleation of recrystallization within various regions of the deformation microstructure.


2020 ◽  
Vol 20 (11) ◽  
pp. 6890-6896
Author(s):  
Woojin An ◽  
Jaewon Heo ◽  
Dongchan Jang ◽  
Kwang Jun Euh ◽  
Im Doo Jung ◽  
...  

The microstructural evolution of Al–Zn–Mg–Cu alloys has been investigated for the homogenization time effect on the texture, grain orientation and dislocation density. The Al–Zn–Mg–Cu alloys were casted and homogenized for 4, 8, 16 and 24 hours. Electron backscatter diffraction (EBSD) analysis was conducted to characterize the microstructural behavior. Micropillars were fabricated using focused ion beam (FIB) milling in grains of specific crystallographic orientations. Coarse precipitations in the grain boundaries are S (Al2CuMg) and T (Al2Mg3Zn3) phases verified by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) observation. With increasing homogenization time, equiaxed cell sizes increased. The volume fraction of S and T phases decreased with the diffusion of atomic elements into matrix. The Vickers hardness and tensile strength values decreased with homogenization temperature. The micropillar compression analysis was compared to macro tensile test results to understand the size effect and strain burst phenomenon on the mechanical properties of Al–Zn–Mg–Cu alloys.


2011 ◽  
Vol 702-703 ◽  
pp. 469-474
Author(s):  
Michael Ferry ◽  
M. Zakaria Quadir ◽  
Nasima Afrin Zinnia ◽  
Lori Bassman ◽  
Cassandra George ◽  
...  

A focused ion beam (FIB) coupled with high resolution electron backscatter diffraction (EBSD) has emerged as a useful tool for generating crystallographic information in reasonably large volumes of microstructure. In principle, data generation is reasonably straightforward whereby the FIB is used as a high precision serial sectioning device for generating consecutive milled surfaces suitable for mapping by EBSD. However, there are several challenges facing the technique including the need for accurate reconstruction of the EBSD slice data and the development of methods for representing the myriad microstructural features of interest including, for example, orientation gradients arising from plastic deformation through to the structure of grains and their interfaces in both single-phase and multi-phase materials. This paper provides an overview of the use of 3D-EBSD in the study of texture development in alloys during deformation and annealing and includes an update on current research on the crystallographic nature of microbands in some body centred and face centred cubic alloys and the nucleation and growth of grains in an extra low carbon steel.


2008 ◽  
Vol 47 (30) ◽  
pp. 5637-5640 ◽  
Author(s):  
Eli Stavitski ◽  
Martyn R. Drury ◽  
D. A. Matthijs de Winter ◽  
Marianne H. F. Kox ◽  
Bert M. Weckhuysen

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5063 ◽  
Author(s):  
Hsia ◽  
Hsiao ◽  
Huang

This article presents a high-voltage (HV) pulse driver based on silicon-on-insulator (SOI) technology for biomedical ultrasound actuators and multi-channel portable imaging systems specifically. The pulse driver, which receives an external low-voltage drive signal and produces high-voltage pulses with a balanced rising and falling edge, is designed by synthesizing high-speed, capacitor-coupled level-shifters with a high-voltage H-bridge output stage. In addition, an on-chip floating power supply has also been developed to simplify powering the entire system and reduce static power consumption. The electrical and acoustic performance of the integrated eight-channel pulse driver has been verified by using medical-grade ultrasound probes to acquire the transmit/echo signals. The driver can produce pulse signals >100 Vpp with rise and fall times within 18.6 and 18.5 ns, respectively. The static power required to support the overall system is less than 3.6 mW, and the power consumption of the system during excitation is less than 50 mW per channel. The second harmonic distortion of the output pulse signal is as low as −40 dBc, indicating that the integrated multi-channel pulse driver can be used in advanced portable ultrasonic imaging systems.


2007 ◽  
Vol 558-559 ◽  
pp. 413-418 ◽  
Author(s):  
Wan Qiang Xu ◽  
Michael Ferry ◽  
Julie M. Cairney ◽  
John F. Humphreys

A typical dual-beam platform combines a focused ion beam (FIB) microscope with a field emission gun scanning electron microscope (FEGSEM). Using FIB-FEGSEM, it is possible to sequentially mill away > ~ 50 nm sections of a material by FIB and characterize, at high resolution, the crystallographic features of each new surface by electron backscatter diffraction (EBSD). The successive images can be combined to generate 3D crystallographic maps of the microstructure. A useful technique is described for FIB milling that allows the reliable reconstruction of 3D microstructures using EBSD. This serial sectioning technique was used to investigate the recrystallization behaviour of a particle-containing nickel alloy, which revealed a number of features of the recrystallizing grains that are not clearly evident in 2D EBSD micrographs such as clear evidence of particle stimulated nucleation (PSN) and twin formation and growth during PSN.


2012 ◽  
Vol 715-716 ◽  
pp. 498-501 ◽  
Author(s):  
Ali Gholinia ◽  
Ian Brough ◽  
John F. Humphreys ◽  
Pete S. Bate

A combination of electron backscatter diffraction (EBSD) and focused ion beam (FIB) techniques were used to obtain 3D EBSD data in an investigation of dynamic recrystallization in a Cu-2%Sn bronze alloy. The results of this investigation show the origin of the nucleation sites for dynamic recrystallization and also elucidates the orientation relationship of the recrystallized grains to the deformed, prior grains and between the dynamically recrystallized grains.


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