Investigation and Numerical Modeling of Aluminum Alloys Depending on Different Thermomechanical Processes

Aluminum alloys produced with Twin Roll Casting (TRC) technology still necessitate to be thoroughly investigated in some areas. Corrosion mechanisms operating under special conditions with the contribution of unique features of the microstructure are among those. Materials produced with TRC have unique features inherently generated due to the solidification path of the material during casting. Contrary to the very fine particles at the locations close to the free surface, centerline segregation (CLS) occurring at the mid-plane of the thickness have different morphological and compositional features than rest of the microstructure. While, unless directly exposed, it has almost no contribution to the general corrosion behavior of the alloy, some manufacturing processes generation new free surfaces in the material for CLS to be exposed to the corrosive media can be harmful for overall general corrosion performance of the alloy. It differentiates itself in corrosion behaviour with its compositional and morphological features than rest of the microstructure. Hence, influence of CLS on corrosion behaviour of two different alloys in 3000 and 8000 series employed for heat exchangers and packaging applications, respectively, are studied in the present study. Since CLS does not disappear with rolling passes but only changes its morphology, samples were taken at appropriate thickness of the downstream process that allow corrosion tests to be conducted at the cross section of the samples. Metallographical preparation techniques were used to reveal the CLS. Samples were dipped in to the HCl-NaCl containing test solution to observe the progress of corrosion in the matrix and heavily populated CLS areas during the course of test. Open-circuit potential (OCP) measurements were carried out on the rolled free surface, quarter plane and mid plane of the samples after milling the surface of the samples. Different samples produced with compositional and thermomechanical processing route variants were used. Results show that composition of the alloy and applied thermomechanical processes influence the corrosion characteristics of CLS and accordingly the overall corrosion performance. Other important finding is the contribution of manufacturing method to corrosion mechanism whether if it reveals the CLS by creating new free cross sectional surfaces.

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Numerical Modeling of Ship Composite-Based on Aluminum Casting as Alternative Materials for Ship Building

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.789.143 ◽

2013 ◽

Vol 789 ◽

pp. 143-150 ◽

Cited By ~ 1

Author(s):

Prantasi Harmi Tjahjanti ◽

Djauhar Manfaat ◽

Eko Panunggal ◽

Darminto ◽

Wibowo Harso Nugroho

Keyword(s):

Numerical Modeling ◽

Aluminum Alloys ◽

Aluminum Casting ◽

Allowable Limit ◽

Ship Building ◽

Vessel Structure ◽

Alternative Material ◽

Wrought Aluminum Alloys ◽

Distribution Of Stress ◽

Wrought Aluminum

The structure and construction of the ship is made of aluminum alloy, generally are of wrought aluminum alloys, when experiencing fatigue failure caused by a cracked vessel structure, is a serious problem. Reviewing of 'weakness' of wrought aluminum alloys for the ship, then in this study tries to provide material alternative for ship building is composite material based on aluminum casting AlSi10Mg (b) and reinforcing material silicon carbide (SiC), which has been in-treatment with the optimum composition 15%. Analysis of numerical computation with the help of ANSYS software version 2.00 to be made numerical modeling ship to ship aluminum EN AC-AlSi10Mg (b) and ship composite EN AC-AlSi10Mg (b)+SiC*/ 15p whether the material can be applied to building ship for see the distribution of stress . The results of the stress distribution in both of model numerical of ship, its value does not exceed the stress permits (sigma 0.2) and have a factor of safety above the minimum allowable limit, so it is safe to use. The overall, in numerical modeling, the ship material aluminum and ship composite materials can be used as an alternative material for ship building, however is still needed comprehensive testing in the field.Keywords: Aluminum casting ; ship building ; composite EN AC-43100(AlSi10Mg (b))+SiC*/15p; ANSYS ver.12,0

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