Numerical Modeling of Microporosity Formation in Aluminum-Rich Aluminum-Copper Alloys in Microgravity Conditions

Mapping Intimacies ◽

10.1115/imece2000-1379 ◽

2000 ◽

Author(s):

M. Xiong ◽

A. V. Kuznetsov

Keyword(s):

Copper Alloys ◽

Heat Transfer Fluid ◽

Gas Phases ◽

Alloy Casting ◽

Cu Alloy ◽

Aluminum Copper Alloys ◽

Three Phase ◽

Microgravity Conditions ◽

Parametric Analyses ◽

Solid Liquid

Abstract The microporosity formation in a vertical unidirectionally solidifying Al-4.1%Cu alloy casting is modeled in both microgravity and standard gravity as well as in the conditions of decreased (Moon, Mars) and increased (Jupiter) gravity. Due to the unique opportunities offered by a low-gravity environment (absence of metallostatic pressure and of natural convection in the solidifying alloy) future microgravity experiments will significantly contribute to attaining a better physical understanding of the mechanisms of microporosity formation. One of the aims of the present theoretical investigation is to predict what microporosity patterns will look like in microgravity in order to help plan a future microgravity experiment. To perform these simulations, the authors suggest a novel three-phase model of solidification that accounts for the solid, liquid, and gas phases in the mushy zone. This model accounts for heat transfer, fluid flow, macrosegregation, and microporosity formation in the solidifying alloy. Special attention is given to the investigation of the influence of microporosity formation on the inverse segregation. Parametric analyses for different initial hydrogen concentrations and different gravity conditions are carried out.

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Generalized Young Equation for Cylindrical Droplets within a Homogeneous and Smooth Regular Triangular Prism Filled with Gas in Three Convex Corners

Mechanical Engineering Research ◽

10.5539/mer.v6n1p14 ◽

2016 ◽

Vol 6 (1) ◽

pp. 14

Author(s):

Long Zhou ◽

Guang-Hua Sun ◽

Ai-Jun Hu ◽

Xiao-Song Wang

Keyword(s):

Line Tension ◽

Phase System ◽

Triangular Prism ◽

Gas Phases ◽

Three Phase ◽

Dividing Surface ◽

Solid Liquid ◽

Wetting Behaviors ◽

Young Equation ◽

Dividing Line

<p class="1Body">Based on the approaches of Gibbs’s dividing surface and Rusanov’s dividing line, the wetting behaviors of cylindrical droplets that at equilibrium are sitting inside a homogeneous and smooth regular triangular prism filled with gas in three convex corners are studied. For the three-phase system, which is composed of solid, liquid and gas phases, a generalized Young equation for cylindrical drops in a homogeneous and smooth regular triangular prism imbued with gas within three apex corners has been successfully derived including the effects of the line tension.</p>

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Effects of Mold Temperature and Casting Temperature on Hot Cracking in Al-4.5 wt.% Cu Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.747.623 ◽

2013 ◽

Vol 747 ◽

pp. 623-626

Author(s):

R. Burapa ◽

S. Rawangwong ◽

J. Chatthong ◽

Worapong Boonchouytan

Keyword(s):

High Resistance ◽

Copper Alloys ◽

Mold Temperature ◽

Hot Cracking ◽

The Other ◽

Casting Temperature ◽

Experimental Conditions ◽

Cu Alloy ◽

Aluminum Copper Alloys ◽

Cracking Tendency

Hot cracking is an important defect that occurs during solidification of aluminum-copper alloys. In this present work, the effects of mold temperature and casting temperature on hot cracking in the Al-4.5 wt.% Cu alloy has been studied using a ring mold for hot cracking assessment. For the experimental conditions, three mold temperatures between 150 and 350°C and three casting temperatures between 670 and 770°C were studied and Al-7 wt.% Si alloy was used as reference for comparison. The results showed Al-7 wt.% Si alloy has high resistance to hot cracking and no hot cracking forms under three different mold temperatures, while Al-4.5 wt.% Cu alloy shows significant hot cracking tendency under the same casting conditions. The severity of hot cracking in Al-4.5 wt.% Cu alloy decreased significantly with increasing the mold temperature and decreasing the casting temperature. On the other hand, an increasing casting temperature resulted in severer hot cracking in Al-4.5 wt.% Cu alloy.

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3D Numerical Analysis of the Asymmetric Three-Phase Line of Floating Zone for Silicon Crystal Growth

Crystals ◽

10.3390/cryst10020121 ◽

2020 ◽

Vol 10 (2) ◽

pp. 121 ◽

Cited By ~ 1

Author(s):

Xue-Feng Han ◽

Xin Liu ◽

Satoshi Nakano ◽

Hirofumi Harada ◽

Yoshiji Miyamura ◽

...

Keyword(s):

Heat Transfer ◽

Silicon Crystal ◽

Three Dimensional ◽

Heat Transfer Fluid ◽

Floating Zone ◽

Phase Line ◽

Three Phase ◽

Em Field ◽

Solid Liquid Interface ◽

Solid Liquid

A numerical simulation has been carried out to study the asymmetric heat transfer, fluid flow, and three-phase line to explain the phenomenon of the spillage of the melt in floating zone (FZ) silicon growth. A three-dimensional high-frequency electromagnetic (EM) field is coupled with the heat transfer in the melt and crystal calculation domains. The current density along the three-phase line is investigated to demonstrate the inhomogeneous heating along the three-phase line. The asymmetric heating is found to affect the flow pattern and temperature distribution of the melt. The three-dimensional solid–liquid interface results show that, below the current supplies, the interface is deflected due to strong heating below the current supplies. The calculated asymmetric three-phase line shows a similar trend as the experimentally observed results. The results indicate that the re-melting and spillage phenomenon could occur below the current supplies.

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Al-Cu Alloy Films Characterization and Studies Using TOF-SIMS, XPS, AFM, EBSD and TEM

ISTFA 2014: Conference Proceedings from the 40th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2014p0496 ◽

2014 ◽

Author(s):

J.J. Shao ◽

Y.Q. Shen ◽

Y. Shen ◽

Y.K. Zhou ◽

K. Li ◽

...

Keyword(s):

Thin Films ◽

Failure Analysis ◽

Copper Alloys ◽

Chemical Properties ◽

Physical And Chemical Properties ◽

Cu Alloy ◽

Tof Sims ◽

Aluminum Copper Alloys ◽

Physical And Chemical ◽

And Chemical Properties

Abstract Aluminum-copper alloys are popular for many applications that take advantage of the combination of properties in the alloys. This paper describes the use of multiple advanced failure analysis tools to analyze the physical and chemical properties of Al-Cu alloy thin films.

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Surfaces Modification of Al-Cu Alloys by Plasma-Assisted CVD

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.199.496 ◽

2013 ◽

Vol 199 ◽

pp. 496-501 ◽

Cited By ~ 5

Author(s):

Karol Kyzioł ◽

Łukasz Kaczmarek ◽

Stanisława Jonas

Keyword(s):

Wear Resistance ◽

Copper Alloys ◽

Chemical Vapour ◽

Argon Plasma ◽

High Strength ◽

Aviation Industry ◽

Cu Alloy ◽

Cu Alloys ◽

Aluminum Copper Alloys ◽

Pre Treatment

Aluminum-copper alloys (Al-Cu) are nowadays widely used in various applications, mainly in automotive and aviation industry, because of their unique properties such as high strength, low density and good corrosion resistance. However, usages of aluminum alloys are partially limited due to their reduced hardness, wear resistance and poor tribological parameters. Desired useful parameters can be improved by application of PA CVD technology. This work presents the results concerning determination and analysis of the structure and the selected properties of the modified surfaces of Al-Cu alloys (2xxx series) that were prepared using plasma assisted MW CVD (Micro-Wave Chemical Vapour Deposition) method. To ensure effectiveness of the substrate modification process, the covered surface was subjected to pre-treatment with argon plasma and/or nitriding process. In conclusion, the research has confirmed that the wear resistance of the Al-Cu alloy can be successfully modified by application of MW CVD technique. The obtained results can serve as a basis in the design of the technology of a-Si:C:N:H layers for diverse applications.

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Effect of copper-enriched layers on localized corrosion of aluminium-copper alloys

Revista Facultad de Ingeniería ◽

10.19053/01211129.v27.n48.2018.8016 ◽

2018 ◽

Vol 27 (48) ◽

Author(s):

María Ángeles Arenas-Vara ◽

Peter Skeldon ◽

Sandra Judith García-Vergara

Keyword(s):

Chloride Solution ◽

Sodium Chloride Solution ◽

Copper Alloys ◽

Localized Corrosion ◽

Pitting Potential ◽

Cu Alloy ◽

Aluminum Copper Alloys ◽

Aluminium Copper ◽

Sputter Deposited ◽

Effect Of Copper

Copper-enriched layers were developed onto aluminum-copper alloys using alkaline etching in sodium hydroxide, for both, sputter deposited and bulk conditions. Enriched alloys were evaluated by potentiodynamic polarization in sodium chloride solution in order to determine the effect of the enriched layers on the pitting potential of the alloys. Rutherford backscattering spectroscopy was employed to quantify the enrichments and their locations just beneath the alumina-based oxides remaining from the etching. For the sputter deposited aluminum-copper alloys, the results show some scattering of the pitting potential data, and no correlation between pitting potential and the alloy enriched layer. In the case of bulk Al-2wt.%Cu alloy, with the copper in solid-solution, the pitting potential increased for the enriched specimens, indicating also a different pit morphology, with respect to the non-enriched alloy.

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