scholarly journals Effect of Grain Size and Micromorphology of Cu Foil on the Velocity of Flyer of Exploding Foil Detonator

2021 ◽  
Vol 11 (14) ◽  
pp. 6598
Author(s):  
Kehua Han ◽  
Peng Deng ◽  
Enyi Chu ◽  
Qingjie Jiao
Keyword(s):  
Grain Size ◽  
Energy Conversion ◽  
Current Density ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Stimulus Response ◽  
The Core ◽  
Grain Sizes ◽  
Cu Film ◽  
Cu Foil

In this paper, the effect of grain size and micromorphology of Cu foil on the velocity of the flyer of an exploding foil detonator was studied. A Cu foil with different grain sizes and micromorphologies was prepared by the physical vapor deposition sputtering method. The flyer velocity of the Cu foil was measured by the photon Doppler technique (PDT). The influence of the grain size and micromorphology of the Cu foil (which was the core transducer of the exploding foil detonator) on the flyer velocity and reacted morphology was discussed. The results show that the grain size and micromorphology of the Cu film can greatly affect the velocity and morphology of the flyer. The grain size of the Cu film is more uniform, and the stimulus response in the middle area of the bridge foil is more concentrated. In addition, the current density becomes more uniform, resulting in a better explosion performance. Consequently, the speed of the formed flyer becomes higher, leading to a smoother flyer surface, which is more conductive to energy conversion.

Grain size, Grain Uniformity, and (111) Texture Enhancement by Solid-phase Crystallization of F- and C-implanted SiGe Films

2000 ◽  
Vol 15 (7) ◽  
pp. 1630-1634 ◽  
Author(s):  
A. Rodríguez ◽  
J. Olivares ◽  
C. González ◽  
J. Sangrador ◽  
T. Rodríguez ◽  
...  
Keyword(s):  
Grain Size ◽  
Vapor Deposition ◽  
Solid Phase ◽  
Chemical Vapor ◽  
Solid Phase Crystallization ◽  
Grain Sizes ◽  
Pressure Chemical ◽  
Film Microstructure ◽  
Si Films ◽  
Size Dispersion

The crystallization kinetics and film microstructure of poly-SiGe layers obtained by solid-phase crystallization of unimplanted and C- and F-implanted 100-nm-thick amorphous SiGe films deposited by low-pressure chemical vapor deposition on thermally oxidized Si wafers were studied. After crystallization, the F- and C-implanted SiGe films showed larger grain sizes, both in-plane and perpendicular to the surface of the sample, than the unimplanted SiGe films. Also, the (111) texture was strongly enhanced when compared to the unimplanted SiGe or Si films. The crystallized F-implanted SiGe samples showed the dendrite-shaped grains characteristic of solid-phase crystallized pure Si. The structure of the unimplanted SiGe and C-implanted SiGe samples consisted of a mixture of grains with well-defined contour and a small number of quasi-dendritic grains. These samples also showed a very low grain-size dispersion.

Study on Two Plasma Physical Vapor Deposition Methods for Preparing Ultrafine Al Powders

2014 ◽  
Vol 556-562 ◽  
pp. 81-85
Author(s):  
Qiong Yu ◽  
Ming Li Li ◽  
Song Ji ◽  
Kun Ming Qian ◽  
Yu Song Zhou
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Direct Current ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Arc Plasma ◽  
Deposition Method ◽  
Micro Structure ◽  
Physical Vapor Deposition Method ◽  
Better Than

Plasma physical vapor deposition method was most widely used to prepare ultrafine Al powders. Direct Current Arc Plasma (DCAP) and Radio Frequency Induction Plasma (RFIP) were adopted individually to produce Al powders with different particle size. The micro structure such as grain size, morphology and crystal phase was examined by SEM, TEM and XRD methods. The results show that the Al production by RFIP was better than by DCAP. DCAP has outstanding advantages in producing nanoAl powders with the particle size below 300nm while the RFIP is better to produce Al powders with the particle size 300nm to 1 μm.

Experimental Investigation of Grain and Specimen Size Effects During Electrical-Assisted Forming

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Michael S. Siopis ◽  
Brad L. Kinsey
Keyword(s):  
Grain Size ◽  
Current Density ◽  
Stress Reduction ◽  
Elevated Temperatures ◽  
Pure Copper ◽  
Electrical Current ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Grain Sizes ◽  
Reduction Effect

Alternative manufacturing processes such as hot working and electrical-assisted forming (EAF), which involves passing a high density electrical current through the workpiece during deformation, have been shown to increase the potential strain induced in materials and reduce required forces for deformation. While forming at elevated temperatures is common, the EAF process provides more significant improvements in formability without the undesirable effects associated with forming at elevated temperatures. This research investigates the effect of grain size and current density on annealed pure copper during the EAF process. The flow stress reduction effect of the process was shown to decrease with increasing grain sizes. A threshold current density, required to achieve a significant reduction in the flow stresses, becomes more apparent at larger grain sizes, and the value increases with increasing grain size. The effects increase with increasing strain due to dislocations being generated during deformation. Therefore, the dislocation density, related in part by the grain size, appears to be a factor in the EAF process.

Experimental Investigation of Grain and Specimen Size Effects During Electrical-Assisted Forming

2009 ◽  
Author(s):  
Michael S. Siopis ◽  
Brad L. Kinsey
Keyword(s):  
Grain Size ◽  
Current Density ◽  
Stress Reduction ◽  
Elevated Temperatures ◽  
Pure Copper ◽  
Electrical Current ◽  
Threshold Current ◽  
Threshold Current Density ◽  
Grain Sizes ◽  
Reduction Effect

Alternative manufacturing processes such as hot working and Electrical-Assisted Forming (EAF), which involves passing a high density electrical current through the workpiece during deformation, have been shown to increase the potential strain induced in materials and reduce required forces for deformation. While forming at elevated temperatures is common, the EAF process provides more significant improvements in formability without the undesirable affects associated with forming at elevated temperatures. This research investigates the effect of grain size and current density on annealed pure copper during the EAF process. The flow stress reduction effect of the process was shown to decrease with increasing grain sizes. A threshold current density, required to achieve a significant reduction in the flow stresses, becomes more apparent at larger grain sizes and the value increases with increasing grain size. The effects increase with increasing strain due to dislocations being generated during deformation. Therefore the dislocation density, related in part by the grain size, appears to be a factor in the EAF process.

CRYSTAL STRUCTURE EFFECT ON ELECTRICAL PROPERTIES OF YSZ CERAMICS

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4005-4009
Author(s):  
CHUNXIA ZHANG ◽  
SHENGKAI GONG ◽  
CHUNGEN ZHOU ◽  
HUIBIN XU
Keyword(s):  
Crystal Structure ◽  
Grain Size ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Nano Particle ◽  
Impedance Spectra ◽  
Two Samples ◽  
Measurement Results ◽  
Molten Particle ◽  
Ac Impedance Spectra

YSZ samples were prepared by Plasma Spray (PS) and Electron Beam Physical Vapor Deposition (EB-PVD) respectively. Microstructure and morphology were observed by SEM and XRD. Grain size of PS-YSZ was non-uniform caused by the inclusion of nano particle by molten particle and column crystal structure was observed for EB-PVD-YSZ. The Arrhenius plots of two samples were graphed by analysis of the measurement results of AC impedance spectra. The conductive mechanisms for EB-PVD and PS YSZ were different due to the crystal structure.

A Microstructural Comparison of Cu(In,Ga)Se2 Thin Films Grown from CuxSe and (In,Ga)2Se3 Precursors

1994 ◽  
Vol 343 ◽  
Author(s):  
Andrew M Gabor ◽  
J. R. Tuttle ◽  
D. S. Albin ◽  
R. Matson ◽  
A. Franz ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Vapor Deposition ◽  
Thin Film Solar Cell ◽  
Physical Vapor Deposition ◽  
The Other ◽  
Device Performance ◽  
Grain Sizes ◽  
Third Stage ◽  
Photovoltaic Solar Cells

ABSTRACTWe fabricated CulnSe2 and Cu(In,Ga)Se2 thin films by two different pathways using physical vapor deposition. In the first we formed a Cu-Se precursor and then reacted it with a flux of (In,Ga) + Se. These films had large grains but were too rough for optimal device performance. In the other pathway, we first formed a smooth precursor of (In,Ga)2Se3 and then exposed it to a flux of Cu+Se. We overshot the optimal film composition to allow recrystallization of the film by a secondary CuxSe phase. We then consumed the excess CuxSe in a third stage deposition of (In,Ga) + Se. The recrystallization step increased the grain sizes, and the resulting films remained smooth. Photovoltaic solar cells made from these films have produced the highest total-area efficiencies of any non-single-crystal, thin-film solar cell.

A Study on the Oxidation Behavior of Nickel Coatings with Different Grain Sizes and Preferred Orientations

2011 ◽  
Vol 183-185 ◽  
pp. 1762-1766 ◽  
Author(s):  
Li Ma ◽  
Ke Chao Zhou ◽  
Lei Zhang ◽  
Zhi You Li
Keyword(s):  
Grain Size ◽  
Oxidation Resistance ◽  
Direct Current ◽  
Current Density ◽  
Oxidation Behavior ◽  
Oxidation Mechanism ◽  
Preferred Orientation ◽  
Size Reduction ◽  
Grain Sizes ◽  
Nickel Coatings

Ni coatings with different grain sizes and preferred orientations were produced by the control of current density during a direct current electrodepositing process. The effects of grain size reduction and preferred orientation on the oxidation behavior in air at 600°C and 960°C of Ni coatings were investigated respectively. An important and interesting result is that after oxidation at 600°C, the Ni coating obtained at lower current density has a better oxidation resistance, whereas after oxidation at 960°C, the Ni coating obtained at higher current density has a more compact scale and a better oxidation resistance. For the Ni coatings oxidation at 600°C, the oxidation behavior was mainly influenced by grain size, whereas in the case of the Ni coatings oxidation at 960°C, the oxidation behavior was only slightly influenced by grain size. The changes in oxidation behavior of Ni coatings at 960°C can be attributed to the different preferred orientation and the corresponding oxidation mechanism.

Grain Size Effect on Optimum Clearance Determination in Blanking Non-Oriented Electrical Steel Sheet

2018 ◽  
Vol 920 ◽  
pp. 34-39
Author(s):  
Zhe Wang ◽  
Rong Gao Cui ◽  
Xin Ke Wang ◽  
Ji He ◽  
Shu Hui Li
Keyword(s):  
Grain Size ◽  
Size Effect ◽  
Electrical Steel ◽  
General Tendency ◽  
Steel Sheets ◽  
The Core ◽  
Grain Sizes ◽  
Edge Quality ◽  
Electrical Steel Sheet ◽  
Electrical Steel Sheets

Non-oriented electrical steel, as the core magnetic material, is firstly blanked into lamination in motor manufacturing. As for the newly developed steel, there is a general tendency toward thinner and coarser-grained. Due to blanking clearance and thickness are both down to the sub-millimeter scale, grain size becomes an important role in formation of blanked edge quality, which mainly determines the deterioration level of magnetic properties. This paper aims to systemically investigate the influence of blanking clearance and grain size on blanked edge quality. In this research, non-oriented electrical steel sheets of the same chemical composition, 3 thicknesses and 3 grain sizes are prepared for blanking tests over the conventional relative blanking clearance range. The blanking edges are quantitatively examined by means of optical microscopy to visualize the distribution of plastic deformation. The results show that there exists an optimum clearance that leads to a fine blanked edge. In further study, an approximate linear equation of the ratio of clearance/grain size (c/D) vs. D is found for optimizing the blanked edge quality. This research thus provides an in-depth understanding and guidance for optimum blanking clearance determination influenced by size effect.

Aspects of microanalysis in a transmission electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 510-511
Author(s):  
R. Sinclair ◽  
B.E. Jacobson
Keyword(s):  
Grain Size ◽  
Electron Beam ◽  
Electron Microscope ◽  
Chemical Analysis ◽  
Transmission Electron Microscope ◽  
Vapor Deposition ◽  
Critical Currents ◽  
X Ray ◽  
Fine Grain ◽  
Transmission Electron

INTRODUCTIONThe prospect of performing chemical analysis of thin specimens at any desired level of resolution is particularly appealing to the materials scientist. Commercial TEM-based systems are now available which virtually provide this capability. The purpose of this contribution is to illustrate its application to problems which would have been intractable until recently, pointing out some current limitations.X-RAY ANALYSISIn an attempt to fabricate superconducting materials with high critical currents and temperature, thin Nb3Sn films have been prepared by electron beam vapor deposition [1]. Fine-grain size material is desirable which may be achieved by codeposition with small amounts of Al2O3 . Figure 1 shows the STEM microstructure, with large (∽ 200 Å dia) voids present at the grain boundaries. Higher quality TEM micrographs (e.g. fig. 2) reveal the presence of small voids within the grains which are absent in pure Nb3Sn prepared under identical conditions. The X-ray spectrum from large (∽ lμ dia) or small (∽100 Ǻ dia) areas within the grains indicates only small amounts of A1 (fig.3).

Sign in / Sign up

Export Citation Format

Share Document