scholarly journals Structure analysis of precursor alloy and diffusion during dealloying of Ag–Al alloy

RSC Advances ◽  
2018 ◽  
Vol 8 (17) ◽  
pp. 9462-9470 ◽  
Author(s):  
Runwei Zhang ◽  
Xu Wang ◽  
Zhichao Zhang ◽  
Jacob C. Huang ◽  
Feng Shi ◽  
...  
Keyword(s):  
Structure Analysis ◽  
Eutectic Composition ◽  
Al Alloy ◽  
Silver Nps ◽  
Precursor Alloy ◽  
And Diffusion

Nanoporous silver (NPS) was fabricated by dealloying Ag–Al alloy ribbons with nominal compositions of 30, 35 and 40 at% Ag (corresponding to hypoeutectic composition, eutectic composition and hypereutectic composition, respectively).

Influence of Silicon on Performance of Al/SiC Composites

2014 ◽  
Vol 592-594 ◽  
pp. 421-425
Author(s):  
G.G. Sozhamannan ◽  
M. Muttharasan ◽  
K. Kaviarasan ◽  
S. Balasivanandha Prabu ◽  
V.S.K. Venkatachalapathy
Keyword(s):  
Hardness Test ◽  
Interface Region ◽  
Al Alloy ◽  
Interface Bonding ◽  
The Matrix ◽  
Different Temperatures ◽  
Matrix Region ◽  
Sic Composites ◽  
And Diffusion ◽  
Hardness Values

Silicon is an important alloying element in Al alloys because the presence of Si improves the hardening strength of Al alloy and improves the wetting between the matrix and the reinforcement. In the present study, Al/SiC bonded specimens were fabricated by means of different temperatures and holding times. The microstructure of the composite was examined by scanning electron microscope. The concentration of Si elements at the interface region was observed by EDS techniques and diffusion of the Si elements in the matrix region was calculated by the Arrhenius equation. The hardness test was performed at the interface region. The results revealed that processing temperatures and holding times influences the concentration of Si and the hardness values near the interface region. Keywords: Al/SiC Interface bonding; SEM; EDS analysis; Micro hardness

X-ray structure analysis of NiTiAl and CuTiAl alloy glasses

1991 ◽  
Vol 134 ◽  
pp. 983-986 ◽  
Author(s):  
M Yamada ◽  
N Matsui ◽  
K Kurita ◽  
K Tanaka ◽  
T Fukunaga ◽  
...  
Keyword(s):  
Structure Analysis ◽  
Al Alloy ◽  
X Ray

Microstructure and Erosion Resistance of Hot-Dip-Aluminized 3Cr13 Steel

2013 ◽  
Vol 750-752 ◽  
pp. 2008-2011
Author(s):  
Zhi Gang Zhao ◽  
Xiu Lin Ji ◽  
Hai Shuai Wang ◽  
Shu Qi Wang
Keyword(s):  
Diffusion Process ◽  
Erosion Resistance ◽  
Alloy Layer ◽  
Ductile Material ◽  
Al Alloy ◽  
Erosion Behavior ◽  
Intermetallic Coating ◽  
Diffusion Temperature ◽  
Erosion Loss ◽  
And Diffusion

Fe-Al intermetallic coating was prepared on 3Cr13 steel by hot-dip aluminizing and diffusion process. The morphology and phase of the coating were analyzed; the erosion behavior of hot-dip-aluminized 3Cr13 steel was investigated. Results showed that the thickness of the coating increased with diffusion temperature, but decreased when diffusion temperature exceeded 800°C. The Fe-Al alloy layer diffused at 900°C presented compacted microstructure, and mainly contained FeAl and a few Fe3Al. Fe-Al intermetallic coating possessed obviously declined erosion loss compared with unaluminized 3Cr13 steel and represented typical erosion characteristics of ductile material.

scholarly journals Pore Structure Analysis of various water-binder ratios Ternary blended Concrete made with

2020 ◽  
Vol 184 ◽  
pp. 01115
Author(s):  
D Adinarayana ◽  
P Srinivasa Rao ◽  
V Srinivasa Reddy
Keyword(s):  
Fly Ash ◽  
Pore Structure ◽  
Structure Analysis ◽  
Chloride Ion ◽  
Chloride Ion Penetration ◽  
Binder Ratio ◽  
Micro Silica ◽  
And Diffusion ◽  
Ternary Blended Concrete ◽  
Pore Structure Analysis

This paper presents the chloride ion penetration and diffusion capability of ternary blended concrete made with various water cement ratios. Ternary blended concrete is made with various combinations of microsilica (MS) and fly ash (FA) for water-binder ratio of 0.55, 0.45 and 0.35. A total of five combinations such as 5% micro-silica + 15% fly ash, 5% micro-silica + 20% fly ash, 10% micro-silica + 15% fly ash , 10% micro-silica + 20% fly ash and 0% micro-silica + 0% fly ash by weight of cement were studied for compressive strength, chloride ion permeability and pore structure analysis. It was found that 5% micro-silica + 15% fly ash showed better performance due to due to well-developed pore structure and microstructure.

scholarly journals Genetic diversity analysis of the invasive gall pest Leptocybe invasa (Hymenoptera: Apodemidae) from China

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258610
Author(s):  
Xin Peng ◽  
Hantang Wang ◽  
Chunhui Guo ◽  
Ping Hu ◽  
Lei Xu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Phylogenetic Tree ◽  
Structure Analysis ◽  
Introgressive Hybridization ◽  
Invasive Pest ◽  
K Value ◽  
Leptocybe Invasa ◽  
And Diffusion ◽  
Amova Analysis

Leptocybe invasa Fisher et LaSalle is a global invasive pest that seriously damages Eucalyptus plants. Studying the genetic diversity, genetic structure and introgression hybridization of L. invasa in China is of great significance for clarifying the breeding strategy, future invasion and diffusion trends of L. invasa in China and developing scientific prevention and control measures. Genetic diversity and phylogenetic analyses of 320 L. invasa female adults from 14 geographic populations in China were conducted using 10 polymorphic microsatellite loci (SSRs) and mitochondrial DNA cytochrome oxidase I gene sequences (COIs). (1) The Bayesian phylogenetic tree and haplotype network diagram showed that only haplotype Hap3 existed in L. invasa lineage B in China, while haplotypes Hap1 and Hap2 existed in lineage A, among which haplotype Hap2 was found for the first time. The nucleotide and haplotype diversities of lineage A were higher than those of lineage B. (2) The SSR genetic diversity of the Wuzhou Guangxi, Ganzhou Jiangxi and Panzhihua Sichuan populations was higher than that of the other 11 populations, and the SSR genetic diversity of lineage A was higher than that of lineage B. (3) The AMOVA analysis of mitochondrial COI data showed that 75.55% of the variation was among populations, and 99.86% of the variation was between lineages, while the AMOVA analysis of nuclear SSR data showed that 35.26% of the variation was among populations, and 47.04% of the variation was between lineages. There were obvious differences in the sources of variation between the COI and SSR data. (4) The optimal K value of COI and SSR data in structure analysis was 2, and PCoA analysis also divided the dataset into two obvious categories. The UPMGA phylogenetic tree based on SSR data clustered 14 geographic species into two groups. The results of genetic structure analysis supported the existence of two lineages, A and B, in China. (5) Structural analysis showed that there was obvious introgressive hybridization in Wuzhou Guangxi, Ganzhou Jiangxi, Panzhihua Sichuan and other populations. These results suggest that lineage introgressive hybridization has occurred in the L. invasa population in China. The introgressive hybridization degree and genetic diversity of lineage A are obviously higher than those of lineage B. Lineage introgressive hybridization may be the driving force for further L. invasa invasion and diffusion in China in the future.

Meridional Circulation, Turbulence, and Diffusion Processes in Stars

1976 ◽  
Vol 32 ◽  
pp. 109-116 ◽  
Author(s):  
S. Vauclair
Keyword(s):  
Convection Zone ◽  
Diffusion Processes ◽  
Meridional Circulation ◽  
Diffusion Time ◽  
Work In Progress ◽  
First Results ◽  
Stellar Envelopes ◽  
And Diffusion ◽  
Turbulence And Diffusion ◽  
Hr Diagram

This paper gives the first results of a work in progress, in collaboration with G. Michaud and G. Vauclair. It is a first attempt to compute the effects of meridional circulation and turbulence on diffusion processes in stellar envelopes. Computations have been made for a 2 Mʘstar, which lies in the Am - δ Scuti region of the HR diagram.Let us recall that in Am stars diffusion cannot occur between the two outer convection zones, contrary to what was assumed by Watson (1970, 1971) and Smith (1971), since they are linked by overshooting (Latour, 1972; Toomre et al., 1975). But diffusion may occur at the bottom of the second convection zone. According to Vauclair et al. (1974), the second convection zone, due to He II ionization, disappears after a time equal to the helium diffusion time, and then diffusion may happen at the bottom of the first convection zone, so that the arguments by Watson and Smith are preserved.

Effets of surfaces on precipitate morphology in irradiated thin foils

1978 ◽  
Vol 36 (1) ◽  
pp. 654-655
Author(s):  
D.I. Potter ◽  
A. Taylor
Keyword(s):  
Ion Irradiation ◽  
Dark Field Image ◽  
Thin Foil ◽  
Dark Field ◽  
Al Alloy ◽  
Bright Field Image ◽  
Dislocation Loops ◽  
Precipitate Morphology ◽  
Thin Foils

Thermal aging of Ni-12.8 at. % A1 and Ni-12.7 at. % Si produces spatially homogeneous dispersions of cuboidal γ'-Ni3Al or Ni3Si precipitate particles arrayed in the Ni solid solution. We have used 3.5-MeV 58Ni+ ion irradiation to examine the effect of irradiation during precipitation on precipitate morphology and distribution. The nearness of free surfaces produced unusual morphologies in foils thinned prior to irradiation. These thin-foil effects will be important during in-situ investigations of precipitation in the HVEM. The thin foil results can be interpreted in terms of observations from bulk irradiations which are described first.Figure 1a is a dark field image of the γ' precipitate 5000 Å beneath the surface(∿1200 Å short of peak damage) of the Ni-Al alloy irradiated in bulk form. The inhomogeneous spatial distribution of γ' results from the presence of voids and dislocation loops which can be seen in the bright field image of the same area, Fig. 1b.

200kv superconducting cryo electron microscope

1987 ◽  
Vol 45 ◽  
pp. 642-643
Author(s):  
M. Iwatsuki ◽  
Y. Kokubo ◽  
Y. Harada ◽  
J. Lehman
Keyword(s):  
Electron Microscope ◽  
Structure Analysis ◽  
Organic Materials ◽  
Strong Interactions ◽  
Specimen Preparation ◽  
Great Effort ◽  
Electron Microscopic ◽  
Crystal Fields ◽  
Special Skill ◽  
Long Time

In recent years, the electron microscope has been significantly improved in resolution and we can obtain routinely atomic-level high resolution images without any special skill. With this improvement, the structure analysis of organic materials has become one of the interesting targets in the biological and polymer crystal fields.Up to now, X-ray structure analysis has been mainly used for such materials. With this method, however, great effort and a long time are required for specimen preparation because of the need for larger crystals. This method can analyze average crystal structure but is insufficient for interpreting it on the atomic or molecular level. The electron microscopic method for organic materials has not only the advantage of specimen preparation but also the capability of providing various information from extremely small specimen regions, using strong interactions between electrons and the substance. On the other hand, however, this strong interaction has a big disadvantage in high radiation damage.

A microscopic marker experiment study on high temperature oxidation of Ni-Al alloy

1986 ◽  
Vol 44 ◽  
pp. 514-515
Author(s):  
Shou-kong Fan
Keyword(s):  
Transport Mechanism ◽  
High Temperature Oxidation ◽  
Transverse Section ◽  
Al Alloy ◽  
Metal Interface ◽  
Electron Microscopic ◽  
Temperature Oxidation ◽  
Analytical Electron ◽  
Microscopic Studies ◽  
First Time

Transmission and analytical electron microscopic studies of scale microstructures and microscopic marker experiments have been carried out in order to determine the transport mechanism in the oxidation of Ni-Al alloy. According to the classical theory, the oxidation of nickel takes place by transport of Ni cations across the scale forming new oxide at the scale/gas interface. Any markers deposited on the Ni surface are expected to remain at the scale/metal interface after oxidation. This investigation using TEM transverse section techniques and deposited microscopic markers shows a different result,which indicates that a considerable amount of oxygen was transported inward. This is the first time that such fine-scale markers have been coupled with high resolution characterization instruments such as TEM/STEM to provide detailed information about evolution of oxide scale microstructure.

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