Characterization of Deformation Mechanics and Microstructure Evolution During Indirect Extrusion in Small Length Scales

2015 ◽  
Author(s):  
Marzyeh Moradi ◽  
Saurabh Basu ◽  
Meenakshisundaram Shankar
Keyword(s):  
High Speed ◽  
Orientation Imaging Microscopy ◽  
Image Correlation ◽  
Dynamic Strain ◽  
Small Length ◽  
In Situ Characterization ◽  
Pure Lead ◽  
Deformation Mechanics

In situ characterization of mechanics of deformation including dynamic strain, strain-rate and rotation of material elements was performed in prototypical small length-scale forming operation- indirect extrusion (IE) of commercially pure Lead (Pb) and Aluminum (Al 1100) using Digital Image Correlation (DIC) technique. Effects of scaling and deformation rate over a range of dimensions and velocities on mechanical response of CP Pb and the resultant anomalies were studied. Additionally, previous and post-deformation characterization of microstructure in Al was accomplished by performing Orientation Imaging Microscopy (OIM) on workpiece materials with different grain sizes. Finally, In situ characterization aided by high speed imaging of indirect extrusion of Al coupled with a Visco-Plastic Self-Consistent (VPSC) model was used to predict the evolved textures in various regions of deformation zone and the results were compared to OIM observations.

scholarly journals In-situ characterization of laser-powder interaction and cooling rates through high-speed imaging of powder bed fusion additive manufacturing

2017 ◽  
Vol 135 ◽  
pp. 385-396 ◽  
Author(s):  
Umberto Scipioni Bertoli ◽  
Gabe Guss ◽  
Sheldon Wu ◽  
Manyalibo J. Matthews ◽  
Julie M. Schoenung
Keyword(s):  
Additive Manufacturing ◽  
High Speed ◽  
Powder Bed Fusion ◽  
In Situ Characterization ◽  
High Speed Imaging ◽  
Cooling Rates ◽  
Powder Bed

In Situ Analysis of Deformation Mechanics of Constrained Cutting Towards Enhanced Material Removal

2019 ◽  
Author(s):  
Yang Guo ◽  
Jisheng Chen ◽  
Amr Saleh
Keyword(s):  
Free Surface ◽  
Surface Finish ◽  
Simple Shear ◽  
Chip Formation ◽  
Material Removal ◽  
High Speed ◽  
Image Correlation ◽  
High Speed Imaging ◽  
Deformation Mechanics

Abstract Chip formation in conventional cutting occurs by deformation that is only partially bounded by the cutting tool. The unconstrained free surface is a complication in determining the deformation of chip formation. The constrained cutting employs a constraining tool in the cutting process to confine the otherwise free surface and enable direct control of the chip formation deformation. A study has been made on the deformation mechanics of plane-strain constrained cutting using high speed imaging and digital image correlation (DIC) methods. For different constrained levels (including unconstrained free cutting), material flow of chip formation is directly observed; strain rate and strain in the chip as well as the subsurface region are quantified; cutting forces are measured; and surface finish are examed. The study shows that chip formation in constrained cutting can occur in two different deformation modes, i.e., simple shear and complex extrusion, depending on the constrained level. Constrained cutting in simple shear regime can reduce strain, reduce cutting force and energy, and improve surface finish compared to free cutting, therefore it is more efficient for material removal than free cutting. Constrained cutting in the complex extrusion regime imposes a significant amount of surface / subsurface deformation and consumes a very high cutting energy, and therefore is not suitable for material removal. Furthermore, the mechanics of chip formation in both free cutting and constrained cutting, especially the roles played by the free surface and the constraining tool, are discussed.

In-Situ Characterization of High-Speed I/O Chip-Package Systems

2007 ◽  
Author(s):  
Jongshick Ahn ◽  
Sudeep Puligundla ◽  
Rizwan Bashirullah ◽  
Robert M. Fox ◽  
William R. Eisenstadt
Keyword(s):  
High Speed ◽  
In Situ Characterization

Wide band frequency and in situ characterization of high permittivity insulators (high-k) for high-speed integrated passives

2005 ◽  
Vol 82 (3-4) ◽  
pp. 548-553 ◽  
Author(s):  
T. Lacrevaz ◽  
B. Fléchet ◽  
A. Farcy ◽  
J. Torres ◽  
M. Gros-Jean ◽  
...  
Keyword(s):  
High Speed ◽  
Wide Band ◽  
In Situ Characterization ◽  
High Permittivity ◽  
Band Frequency ◽  
Integrated Passives ◽  
High K

scholarly journals In situ Characterization of Laser Powder Bed Fusion Using High-Speed Synchrotron X-ray Imaging Technique

2019 ◽  
Vol 25 (S2) ◽  
pp. 2566-2567 ◽  
Author(s):  
Niranjan Parab ◽  
Cang Zhao ◽  
Ross Cunningham ◽  
Luis I. Escano ◽  
Kamel Fezzaa ◽  
...  
Keyword(s):  
High Speed ◽  
Imaging Technique ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
In Situ Characterization ◽  
Powder Bed ◽  
X Ray ◽  
X Ray Imaging

scholarly journals In situ characterization of laser-generated melt pools using synchronized ultrasound and high-speed X-ray imaging

2021 ◽  
Vol 150 (4) ◽  
pp. 2409-2420
Author(s):  
Jared Gillespie ◽  
Wei Yi Yeoh ◽  
Cang Zhao ◽  
Niranjan D. Parab ◽  
Tao Sun ◽  
...  
Keyword(s):  
High Speed ◽  
In Situ Characterization ◽  
X Ray ◽  
X Ray Imaging

Characterization of the glycoconjugates of boar testis and epididymis

Reproduction ◽  
2000 ◽  
pp. 325-335 ◽  
Author(s):  
A Calvo ◽  
LM Pastor ◽  
S Bonet ◽  
E Pinart ◽  
M Ventura
Keyword(s):  
Ricinus Communis ◽  
Lectin Histochemistry ◽  
Apical Part ◽  
Seminiferous Tubules ◽  
In Situ Characterization ◽  
Intense Staining ◽  
Terminal Galactose ◽  
Boar Spermatozoa

Lectin histochemistry was used to perform in situ characterization of the glycoconjugates present in boar testis and epididymis. Thirteen horseradish peroxidase- or digoxigenin-labelled lectins were used in samples obtained from healthy fertile boars. The acrosomes of the spermatids were stained intensely by lectins with affinity for galactose and N-acetyl-galactosamine residues, these being soybean, peanut and Ricinus communis agglutinins. Sertoli cells were stained selectively by Maackia ammurensis agglutinin. The lamina propria of seminiferous tubules showed the most intense staining with fucose-binding lectins. The Golgi area and the apical part of the principal cells of the epididymis were stained intensely with many lectins and their distribution was similar in the three zones of the epididymis. On the basis of lectin affinity, both testis and epididymis appear to have N- and O-linked glycoconjugates. Spermatozoa from different epididymal regions showed different expression of terminal galactose and N-acetyl-galactosamine. Sialic acid (specifically alpha2,3 neuraminic-5 acid) was probably incorporated into spermatozoa along the extratesticular ducts. These findings indicate that the development and maturation of boar spermatozoa are accompanied by changes in glycoconjugates. As some lectins stain cellular or extracellular compartments specifically, these lectins could be useful markers in histopathological evaluation of diseases of boar testis and epididymis.

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